WorldWideScience

Sample records for climatology

  1. Climatology

    International Nuclear Information System (INIS)

    Climatology is an important field of continuing interest in nearly all fields of science and beyond. In view of this interdisciplinary role, the textbook gives an accurate and intelligible introduction to the fundamentals and modern aspects of general climatology. It covers the basic concepts of climate elements, the physical processes, atmospheric circulation and further components of the ''climate system'' (ocean, ice, continents), as well as an explanation of the observed field characteristics of the climate, problems of climate modelling fundamentals of bioclimatology, and, last but not least, key aspects of climate history and anthropogenic effects on climate. (orig.)

  2. Preciptation Climatologies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In the mid-1970s, the National Climate Center used precipitation data to calculate various climatology products, studying the climatic probability of precipitation....

  3. Urban Climatology

    Science.gov (United States)

    Brazel, Anthony J.; Quattrochi, Dale A.; Arnold, James E. (Technical Monitor)

    2002-01-01

    This section on Urban Climates provides a basic understanding of what comprises the urban climate and what factors control the overall development of the urban climate. We also discuss in this section, methods for evaluating urban climate characteristics and forcing functions as well as how the urban heat island effect comes into play as a dynamic influence on urban climatology. Additionally, we examine and discuss the major radiation and energy balance of city (i.e., shortwave and longwave radiation, albedo, net all-wave radiation, total energy balance, and sensible latent, and storage heat) and the interactions of these energy balances with the lower atmosphere. The use of remote sensing to measure urban surface temperatures as a driving force in the development of the urban heat island effect is presented. We also discuss how the overall moisture, precipitation, humidity, and air movement in cities (i,e,, wind speeds and wind direction) and wind environment of the city affects urban climatology.

  4. Preliminary Monthly Climatological Summaries

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Preliminary Local Climatological Data, recorded since 1970 on Weather Burean Form 1030 and then National Weather Service Form F-6. The preliminary climate data...

  5. Climatological Data National Summary

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CDNS was published from 1950 - 1980. Monthly and annual editions contain summarized climatological information from the following publications: Local...

  6. Global Synoptic Climatology Network

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Global Synoptic Climatology Network is a digital data set archived at the National Climatic Data Center (NCDC). This record combines the various types of data that...

  7. Historical Climatology Series

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Historical Climatology Series (HCS) is a set of climate-related publications published by NOAA's National Climatic Data Center beginning in 1978. HCS is...

  8. Reference Climatological Stations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Reference Climatological Stations (RCS) network represents the first effort by NOAA to create and maintain a nationwide network of stations located only in...

  9. Climatological Services Memorandums

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Climatological Services Memorandums were a series of memoranda issued by the Weather Bureau for the purpose of keeping all stations informed on the status and...

  10. Local Climatological Data ACSII Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Comma-delimited text files used to create the Local Climatological Data PDF files found in the Local Climatological Data library. Period of record begins in 1998,...

  11. Hydro-climatology

    DEFF Research Database (Denmark)

    The hydro-climatological approach of this volume illustrates the scientific and practical value of considering hydrological phenomena and processes in a climate context to improve understanding of controls, process interaction, and past and future variability/change. Contributions deal with...

  12. Situational Lightning Climatologies

    Science.gov (United States)

    Bauman, William; Crawford, Winifred

    2010-01-01

    Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. It was believed there were two flow systems, but it has been discovered that actually there are seven distinct flow regimes. The Applied Meteorology Unit (AMU) has recalculated the lightning climatologies for the Shuttle Landing Facility (SLF), and the eight airfields in the National Weather Service in Melbourne (NWS MLB) County Warning Area (CWA) using individual lightning strike data to improve the accuracy of the climatologies. The software determines the location of each CG lightning strike with 5-, 10-, 20-, and 30-nmi (.9.3-, 18.5-, 37-, 55.6-km) radii from each airfield. Each CG lightning strike is binned at 1-, 3-, and 6-hour intervals at each specified radius. The software merges the CG lightning strike time intervals and distance with each wind flow regime and creates probability statistics for each time interval, radii, and flow regime, and stratifies them by month and warm season. The AMU also updated the graphical user interface (GUI) with the new data.

  13. Applications of climatological measurements

    International Nuclear Information System (INIS)

    More than 18 years of meteorological data have been collected by the Meteorological Group at the Argonne National Laboratory. These data have been useful in the day-to-day operations of the Laboratory and in the preparation of reactor hazard reports as well as in support of atmospheric research projects, such as our radon, wind profile, plume rise and smoke diffusion studies. A climatological report, covering 15 years of data, has been prepared and will be published soon. A summary of a study of the meteorological conditions giving rise to dew point inversions (moisture content increasing with height near the ground) is given as an example of the type of studies that can be made with these data. (author)

  14. Regional climatology sensitivity studies

    International Nuclear Information System (INIS)

    Regional interest in understanding climate and climate change at regional scales has led to the application of mesoscale models for regional climatology studies. These models can provide an understanding of climate processes in a physically consistent way at much higher resolution than currently offered by general circulation models (GCMs). This paper presents results from two simple regional climate sensitivity experiments designed to test the impact of grid configuration on the prediction of precipitation. The simulated precipitation was first compared with observed data interpolated to model grid points. Assessing the accuracy of the modeling results is complicated by the fact that the mesoscale precipitation data set used for model validation is too sparse to provide a rigorous evaluation of the model's performance. The modeling results show that grid configuration must be given very careful consideration before a regional model can be implemented for climate studies over a particular area of interest. Results presented here suggest that seemingly minor changes in domain boundaries and grid resolution can have a dramatic impact upon predicted results

  15. Local Climatological Data (LCD) Publication

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Local Climatological Data (LCD) contains summaries from major airport weather stations that include a daily account of temperature extremes, degree days,...

  16. A global monthly sea surface temperature climatology

    Science.gov (United States)

    Shea, Dennis J.; Trenberth, Kevin E.; Reynolds, Richard W.

    1992-01-01

    The paper presents a new global 2 deg x 2 deg monthly sea surface temperature (SST) climatology, referred here to as the Shea-Trenberth-Reynolds (STR) climatology, which was derived by modifying a 1950-1979-based SST climatology from the Climate Analysis Center (CAC), by using data from the Comprehensive Ocean-Atmosphere Data Set to improve the SST estimates in the regions of the Kuroshio and the Gulf Stream. A comparison of the STR climatology with the Alexander and Mobley SST climatology showed that the STR climatology is warmer in the Northern Hemisphere, and colder poleward of 45 deg S.

  17. U.S. Local Climatological Data (LCD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Local Climatological Data (LCD) are summaries of climatological conditions from airport and other prominent weather stations managed by NWS, FAA, and DOD. The...

  18. Active Learning in Introductory Climatology.

    Science.gov (United States)

    Dewey, Kenneth F.; Meyer, Steven J.

    2000-01-01

    Introduces a software package available for the climatology curriculum that determines possible climatic events according to a long-term climate history. Describes the integration of the software into the curriculum and presents examples of active learning. (Contains 19 references.) (YDS)

  19. SPARC Data Initiative: climatology uncertainty assessment

    OpenAIRE

    Toohey, Matthew; T. von Clarmann; Hegglin, M.; Tegtmeier, Susann

    2011-01-01

    The SPARC Data Initiative aims to produce trace gas climatologies for a number of species from a number of instruments. In order to properly compare these climatologies, and interpret differences between them, it is necessary to know the uncertainty in each calculated climatological mean field. The inhomogeneous and finite temporal-spatial sampling pattern of each instrument can lead to biases and uncertainties in the mean climatologies. Sampling which is unevenly weighted in time and space l...

  20. TRMM-Based Lightning Climatology

    Science.gov (United States)

    Cecil, Daniel J.; Buechler, Dennis E.; Blakeslee, Richard J.

    2011-01-01

    Gridded climatologies of total lightning flash rates seen by the spaceborne Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) have been updated. OTD collected data from May 1995 to March 2000. LIS data (equatorward of about 38 deg) has been added for 1998-2010. Flash counts from each instrument are scaled by the best available estimates of detection efficiency. The long LIS record makes the merged climatology most robust in the tropics and subtropics, while the high latitude data is entirely from OTD. The mean global flash rate from the merged climatology is 46 flashes per second. The peak annual flash rate at 0.5 deg scale is 160 fl/square km/yr in eastern Congo. The peak monthly average flash rate at 2.5 scale is 18 fl/square km/mo, from early April to early May in the Brahmaputra Valley of far eastern India. Lightning decreases in this region during the monsoon season, but increases further north and west. A monthly average peak from early August to early September in northern Pakistan also exceeds any monthly averages from Africa, despite central Africa having the greatest yearly average. Most continental regions away from the equator have an annual cycle with lightning flash rates peaking in late spring or summer. The main exceptions are India and southeast Asia, with springtime peaks in April and May. For landmasses near the equator, flash rates peak near the equinoxes. For many oceanic regions, the peak flash rates occur in autumn. This is particularly noticeable for the Mediterranean and North Atlantic. Landmasses have a strong diurnal cycle of lightning, with flash rates generally peaking between 3-5 pm local solar time. The central United States flash rates peak later, in late evening or early night. Flash rates peak after midnight in northern Argentina. These regions are known for large, intense, long-lived mesoscale convective systems.

  1. International Satellite Cloud Climatology Project (ISCCP)

    Data.gov (United States)

    National Aeronautics and Space Administration — International Satellite Cloud Climatology Project (ISCCP) focuses on the distribution and variation of cloud radiative properties to improve the understanding of...

  2. The NEWS Water Cycle Climatology

    Science.gov (United States)

    Rodell, Matthew; Beaudoing, Hiroko Kato; L'Ecuyer, Tristan; William, Olson

    2012-01-01

    NASA's Energy and Water Cycle Study (NEWS) program fosters collaborative research towards improved quantification and prediction of water and energy cycle consequences of climate change. In order to measure change, it is first necessary to describe current conditions. The goal of the first phase of the NEWS Water and Energy Cycle Climatology project was to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. The project was a multi-institutional collaboration with more than 20 active contributors. This presentation will describe the results of the water cycle component of the first phase of the project, which include seasonal (monthly) climatologies of water fluxes over land, ocean, and atmosphere at continental and ocean basin scales. The requirement of closure of the water budget (i.e., mass conservation) at various scales was exploited to constrain the flux estimates via an optimization approach that will also be described. Further, error assessments were included with the input datasets, and we examine these in relation to inferred uncertainty in the optimized flux estimates in order to gauge our current ability to close the water budget within an expected uncertainty range.

  3. 30 CFR 779.18 - Climatological information.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Climatological information. 779.18 Section 779... PROGRAMS SURFACE MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR INFORMATION ON ENVIRONMENTAL RESOURCES § 779.18 Climatological information. (a) When requested by the regulatory authority, the...

  4. 30 CFR 783.18 - Climatological information.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Climatological information. 783.18 Section 783... PROGRAMS UNDERGROUND MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR INFORMATION ON ENVIRONMENTAL RESOURCES § 783.18 Climatological information. (a) When requested by the regulatory authority,...

  5. Climatological features of blocking anticyclones

    International Nuclear Information System (INIS)

    Several climatological studies have been previously performed using large observational data sets (i.e., 10 years or longer) in order to determine the predominant characteristics of blocking anticyclones, including favored development regions, duration, preferred seasonal occurrence, and frequency of occurrence. These studies have shown that blocking anticyclones occur most frequently from October to April over the eastern Atlantic and Pacific oceans downstream from both the North American and Asian continental regions and the storm track regions to the east of these continents. Some studies have also revealed the presence of a third region block formation in western Russia near 40 degrees E which is associated with another storm track region over the Mediterranean and western Asia

  6. Quality Controlled Local Climatological Data (QCLCD) Publication

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quality Controlled Local Climatological Data (QCLCD) contains summaries from major airport weather stations that include a daily account of temperature extremes,...

  7. U.S. Annual Climatological Summaries

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Annual Climatological Summary contains historical monthly and annual summaries for over 8000 U.S. locations. Observing stations are located in the United States of...

  8. Global Daily Climatology Network: Kazakhstan subset

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a compilation of in situ daily meteorological observations for Kazakhstan within the framework of joint efforts to create Global Daily Climatology...

  9. Climatology of ionospheric slab thickness

    Directory of Open Access Journals (Sweden)

    B. Jayachandran

    2004-01-01

    Full Text Available The ionospheric slab thickness τ defined as a ratio of the total electron content (TEC to the F-region peak electron density (NmF2 has been analysed during the solar maximum (1981 and minimum (1985 phases of an intense, the 21st, solar cycle. Hourly values of TEC and NmF2 collected at Hawaii (low-latitude, Boulder (mid-latitude and Goosebay (high-latitude are used in the study. Climatology of the slab thickness is described by the diurnal, seasonal, solar and magnetic activity variations of τ for the different latitude zones. It is found that, for magnetically quiet days of solar maximum, increased ionization of NmF2 and TEC during the daytime is accompanied by an increased thickness of the ionosphere compared to the night-time for non-auroral latitudes. However, the reverse is found to be true during the solar minimum compensating TEC against a weak night-time ionization of NmF2. For the high-latitude the night-time slab thickness is higher compared to the daytime for both the solar phases. Ratios of daily peak to minimum values of slab thickness vary from 1.3 to 3.75 with the peaks of τ often observed at pre-sunrise and post-sunset hours. The average night-to-day ratios of τ vary from 0.68 to 2.23. The day-to-day variability of τ, expressed in percentage standard deviation, varies from 10% by day (equinox, high-latitude to 67% by night (summer, mid-latitude during solar minimum and from 10% by day (winter and equinox, mid-latitude to 56% by night (equinox, high-latitude during solar maximum. A comprehensive review of slab thickness related literature is given in the paper.

    Key words. Ionospheric physics

  10. Climatology of hail in France

    Science.gov (United States)

    Vinet, Freddy

    Within the framework of a doctoral thesis in geography, we endeavored to draw up the first map showing hail risk in France. The creation of this map is mainly based on the data of hail measuring networks. This map is corroborated, moreover, by the analysis of hail damage maps. Insurance data used to measure relative hail damage are the base premium rate levels expressed as a percentage of assets insured on a single crop, in this case grapes. These levels reflect well, over the long term, the regional hierarchy of damage, without it being necessary to correlate them directly in terms of frequency and intensity of hail. The regions that suffer the most hail stretch from the southwest to the east-central area of France, passing through the Massif Central. One must also note the southern Alps as a strongly hail-prone region. From the diagonal line of high hail risk emerge two gradients of decreasing intensity and frequency of hail. Toward the west, the risk of hail diminishes strongly, attaining a minimum level in Brittany and on the English Channel coast. Toward the southeast, hail diminishes near the Mediterranean coast. The climatological explanations of this map are so far only hypotheses. Hail is not the exclusive feature of a single climate; it seems on the contrary to be the hallmark of regions of climatic contact. The line of maximal hail risk is situated at the frontier between the oceanic and Mediterranean influences. This conflict is readily measurable in the southwest part of France where the pyrenees channel the Mediterranean influences at low levels. The map of hail risk is also the reflection of the probability of southwestern flow at high altitudes. In the east-central area of France (around Lyon), the local topography can amplify hail energy especially on leeward slopes.

  11. A global satellite assisted precipitation climatology

    Science.gov (United States)

    Funk, Christopher C.; Verdin, Andrew P.; Michaelsen, Joel C.; Pedreros, Diego; Husak, Gregory J.; Peterson, P.

    2015-01-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05°) global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  12. A global satellite assisted precipitation climatology

    Directory of Open Access Journals (Sweden)

    C. Funk

    2015-05-01

    Full Text Available Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05° global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology

  13. A global satellite-assisted precipitation climatology

    Science.gov (United States)

    Funk, C.; Verdin, A.; Michaelsen, J.; Peterson, P.; Pedreros, D.; Husak, G.

    2015-10-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high-resolution (0.05°) global precipitation climatologies that perform reasonably well in data-sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  14. SPARC Intercomparison of Middle Atmosphere Climatologies

    Science.gov (United States)

    Randel, William; Fleming, Eric; Geller, Marvin; Hamilton, Kevin; Karoly, David; Ortland, Dave; Pawson, Steve; Swinbank, Richard; Udelhofen, Petra

    2002-01-01

    This atlas presents detailed incomparisons of several climatological wind and temperature data sets which cover the middle atmosphere (over altitudes approx. 10-80 km). A number of middle atmosphere climatologies have been developed in the research community based on a variety of meteorological analyses and satellite data sets. Here we present comparisons between these climatological data sets for a number of basic circulation statistics, such as zonal mean temperature, winds and eddy flux statistics. Special attention is focused on tropical winds and temperatures, where large differences exist among separate analyses. We also include comparisons between the global climatologies and historical rocketsonde wind and temperature measurements, and also with more recent lidar temperature data. These comparisons highlight differences and uncertainties in contemporary middle atmosphere data sets, and allow biases in particular analyses to be isolated. In addition, a brief atlas of zonal mean temperature and wind statistics is provided to highlight data availability and as a quick-look reference. This technical report is intended as a companion to the climatological data sets held in archive at the SPARC Data Center (http://www.sparc.sunysb.edu).

  15. The lightning climatology of South Africa

    Directory of Open Access Journals (Sweden)

    Morné Gijben

    2012-03-01

    Full Text Available In 2005, the South African Weather Service installed a state-of-the-art cloud-to-ground lightning detection network across the country. The data recorded by this network in 2006 was utilised in the development of an initial lightning climatology of South Africa. Until 2010, this climatology was based on data from a single year. This paper updates this climatology with the lightning data for the 2006–2010 period, which is the first actual lightning climatology by the South African Weather Service based on data covering 5 years. A number of different maps were created from these lightning data. These were lightning ground flash density, median peak kiloampere, percentage positive and average flash multiplicity maps. These four maps were in turn used to develop lightning intensity risk, positive lightning risk and total lightning risk maps. Analysis of the maps showed that the highest concentrations of lightning are found over the central to northern interior of the country, with areas along the northern parts of the eastern escarpment experiencing the highest flash densities and falling within the extreme risk category. Both the positive and total lightning risks are severe for almost the entire country. Only towards the west of the country does the lightning risk decrease. This lightning climatology can now be used throughout South Africa for various disciplines. It will be especially useful for setting lightning safety standards and identifying priority areas for installing lightning conductors and conducting public awareness campaigns.

  16. Comparative Climatology of Terrestrial Planets

    Science.gov (United States)

    Mackwell, Stephen J.; Simon-Miller, Amy A.; Harder, Jerald W.; Bullock, Mark A.

    stimulate further research on this critical subject. The study of climate involves much more than understanding atmospheric processes. This subtlety is particularly appreciated for Earth, where chemical cycles, geology, ocean influences, and biology are considered in most climate models. In Part IV, Surface and Interior, we look at the role that geochemical cycles, volcanism, and interior mantle processes play in the stability and evolution of terrestrial planetary climates. There is one vital commonality between the climates of all the planets of the solar system: Regardless of the different processes that dominate each of the climates of Earth, Mars, Venus, and Titan, they are all ultimately forced by radiation from the same star, albeit at variable distances. In Part V, Solar Influences, we discuss how the Sun's early evolution affected the climates of the terrestrial planets, and how it continues to control the temperatures and compositions of planetary atmospheres. This will be of particular interest as models of exoplanets, and the influences of much different stellar types and distances, are advanced by further observations. Comparisons of atmospheric and climate processes between the planets in our solar system has been a focus of numerous conferences over the past decade, including the Exoclimes conference series. In particular, this book project was closely tied to a conference on Comparative Climatology of Terrestrial Planets that was held in Boulder, Colorado, on June 25-28, 2012. This book benefited from the opportunity for the author teams to interact and obtain feedback from the broader community, but the chapters do not in general tie directly to presentations at the conference. The conference, which was organized by a diverse group of atmospheric and climate scientists led by Mark Bullock and Lori Glaze, sought to build connections between the various communities, focusing on synergies and complementary capabilities. Discussion panels at the end of most

  17. Dispersion climatology in a coastal zone

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling; Gryning, Sven-Erik

    1986-01-01

    system should be used to describe the dispersion. This dispersion classification scheme is used to organize 3 years of data from two meteorological masts, one placed directly at a shoreline and the other roughly 1 km inland. Differences in the dispersion climatology over land and water are studied by...... averaging the data selectively. The large differences for water and land surfaces between the seasonal and diurnal variation of the dispersion class distributions are illustrated. It is found that the water surface influences the dispersion climatology as far as 20 km inland....

  18. NORSEWInD satellite wind climatology

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Mouche, Alexis;

    provide new offshore wind climatology map for the entire area of interest based on satellite remote sensing. This has been based on Synthetic Aperture Radar (SAR) from Envisat ASAR using 9000 scenes re-processed with ECMWF wind direction and CMOD-IFR. The number of overlapping samples range from 450 in...

  19. Climatological variability in regional air pollution

    International Nuclear Information System (INIS)

    Although some air pollution modeling studies examine events that have already occurred (e.g., the Chernobyl plume) with relevant meteorological conditions largely known, most pollution modeling studies address expected or potential scenarios for the future. Future meteorological conditions, the major pollutant forcing function other than emissions, are inherently uncertain although much relevant information is contained in past observational data. For convenience in our discussions of regional pollutant variability unrelated to emission changes, we define meteorological variability as short-term (within-season) pollutant variability and climatological variability as year-to-year changes in seasonal averages and accumulations of pollutant variables. In observations and in some of our simulations the effects are confounded because for seasons of two different years both the mean and the within-season character of a pollutant variable may change. Effects of climatological and meteorological variability on means and distributions of air pollution parameters, particularly those related to regional visibility, are illustrated. Over periods of up to a decade climatological variability may mask or overstate improvements resulting from emission controls. The importance of including climatological uncertainties in assessing potential policies, particularly when based partly on calculated source-receptor relationships, is highlighted

  20. A novel tropopause-related climatology of ozone profiles

    NARCIS (Netherlands)

    Sofieva, V.F.; Tamminen, J.; Kyrola, E.; Mielonen, T.; Veefkind, J.P.; Hassler, B.; Bodeker, G.E.

    2014-01-01

    A new ozone climatology, based on ozonesonde and satellite measurements, spanning the altitude region between the earth's surface and ~60 km is presented (TpO3 climatology). This climatology is novel in that the ozone profiles are categorized according to calendar month, latitude and local tropopaus

  1. A new evaporation duct climatology over the South China Sea

    Science.gov (United States)

    Shi, Yang; Yang, Kunde; Yang, Yixin; Ma, Yuanliang

    2015-10-01

    The climatology of evaporation ducts is important for shipborne electromagnetic system design and application. The evaporation duct climatology that is currently used for such applications was developed in the mid 1980s; this study presents efforts to improve it over the South China Sea (SCS) by using a state-of-the-art evaporation duct model and an improved meteorology dataset. This new climatology provides better evaporation duct height (EDH) data over the SCS, at a higher resolution of 0.312°×0.313°. A comparison between the new climatology and the old one is performed. The monthly average EDH in the new climatology is between 10 and 12 m over the SCS, higher than that in the old climatology. The spatiotemporal characteristics of the evaporation duct over the SCS in different months are analyzed in detail, based on the new climatology.

  2. Regional and applied climatology-contributions

    International Nuclear Information System (INIS)

    The first three articles of this book, which is dedicated to Wolfgang Weischet, are closely related to his work on unban climatology: - A comprehensive research programme on urban climatology for the example of a medium-sized Swiss town; - A wind tunnel test in preparation of a large-scale urban construction project; - Modelling of human thermal comfort in different urban environments on the basis of comprehensive data sets of geofactors. At the same time, they provide a survey of the status and methods of modern urban climate research. The second group of contributions comprises texts which discuss the effects of individual climate elements in the biosphere and pedosphere. The third group consists of two contributions on the stability of tropical environments. Both of them discuss the semiarid regions of northern Kenia. Finally, there is a group of contributions stimulated and influenced by W. Weischet's work in Latin America. (orig./KW)

  3. Climatology of local flow patterns around Basel

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R.O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Recently a method has been developed to classify local-scale flow patterns from the wind measurements at a dense network of stations. It was found that in the MISTRAL area around Basel a dozen characteristic flow patterns occur. However, as the dense network of stations ran only during one year, no reliable climatology can be inferred from these data, especially the annual cycle of the flow patterns is not well determined from a single year of observations. As there exist several routinely operated stations in and near the MISTRAL area, a method was searched to identify the local flow patterns from the observations at the few routine stations. A linear discriminant analysis turned out to be the best method. Based of data from 11 stations which were simultaneously operated during 1990-1995 a six-year climatology of the flow patterns could be obtained. (author) 1 fig., 1 tab., 3 refs.

  4. The SPARC Intercomparison of Middle Atmosphere Climatologies

    Science.gov (United States)

    Randel, William; Fleming, Eric; Geller, Marvin; Gelman, Mel; Hamilton, Kevin; Karoly, David; Ortland, Dave; Pawson, Steve; Swinbank, Richard; Udelhofen, Petra

    2003-01-01

    Our current confidence in 'observed' climatological winds and temperatures in the middle atmosphere (over altitudes approx. 10-80 km) is assessed by detailed intercomparisons of contemporary and historic data sets. These data sets include global meteorological analyses and assimilations, climatologies derived from research satellite measurements, and historical reference atmosphere circulation statistics. We also include comparisons with historical rocketsonde wind and temperature data, and with more recent lidar temperature measurements. The comparisons focus on a few basic circulation statistics, such as temperature, zonal wind, and eddy flux statistics. Special attention is focused on tropical winds and temperatures, where large differences exist among separate analyses. Assimilated data sets provide the most realistic tropical variability, but substantial differences exist among current schemes.

  5. Recent Progresses on Ionospheric Climatology Investigations

    Institute of Scientific and Technical Information of China (English)

    LIU Libo; WAN Weixing; CHEN Yiding; LE Huijun; ZHAO Biqiang

    2012-01-01

    The ionosphere varies over multiple time scales, which are classified into two categories: the climatology and weather variations. In this national report, we give a brief summary of recent progresses in ionospheric climatology with focus on (i) the seasonal variations, (2) solar cycle effects, and (3) empirical modeling of the ionosphere. The seasonal variations of the ionosphere have been explored in many works to give a more detailed picture with regional and global features at various altitudes by analyzing the observation data from various sources and models. Moreover, a series of studies reported the response of the ionosphere to solar cycle variations, which revealed some novel and detailed features of solar activity dependence of ionospheric parameters at different altitudes. These investigations have improved our understanding on the states of the ionosphere and underlying fundamental processes, provided clues to future studies on ionospheric weather, and guided ionospheric modeling, forecasting and related applications.

  6. Results of large scale wind climatologically estimations

    Directory of Open Access Journals (Sweden)

    Andrea Kircsi

    2008-05-01

    Full Text Available The aim of this article is to describe theparticular field of climatology which analyzes airmovement characteristics regarding utilization of windfor energy generation. The article describes features ofwind energy potential available in Hungary compared towind conditions in other areas of the northern quartersphere in order to assist the wind energy use developmentin Hungary. Information on wind climate gives a solidbasis for financial and economic decisions ofstakeholders in the field of wind energy utilization.

  7. Development and application of Labrador Sea climatologies

    Science.gov (United States)

    Cetin, Nilgun

    2007-05-01

    Two yearly climatologies of the Labrador Sea are developed. One is based on the traditional geopotential coordinates, and the other employs isopycnal coordinates in the vertical. The analysis of the results show that the isopycnal climatology has more skill at describing the mean state of the Labrador Sea, without smoothing out important flow features such as strong boundary currents and fronts. Seasonal climatologies based on the isopycnal coordinates in the vertical are also developed to study seasonal variability of the Labrador Sea hydrography and freshwater and heat fluxes. The greatest seasonal variability is observed in winter, the season in which deep convective overturning takes place. By using the objective analysis technique which successfully represented the dynamics of the Labrador Sea, a pseudo time-series of water properties is developed to study their inter-annual variability. The contribution of the West Greenland Current to the interior Labrador Sea freshwater budget is found to be greater than that of the Labrador Current, even though the Labrador Current has a larger freshwater content. Diagnostic calculations show that the Labrador Current flows southward mostly parallel to the isobaths without much of its fresher waters ever crossing into the interior Labrador Sea.

  8. Climatological data summary 1994, with historical data

    International Nuclear Information System (INIS)

    This document presents the climatological data measured at the U.S. Department of Energy's Hanford Site for calendar year 1994. Pacific Northwest Laboratory operates the Hanford Meteorology Station and the Hanford Meteorological Monitoring Network from which these data were collected. The information contained herein includes updated historical climatologies for temperature, precipitation, normal and extreme values of temperature and precipitation, and other miscellaneous meteorological parameters. Further, the data are adjunct to and update Hoitink et al. (1994); however, Appendix B-Wind Climatology is excluded. 1994 was the second warmest year on record, averaging 56.2 degrees F, 2.9 degrees F above normal (53.3 degrees F). For the 12-month period, 10 were warmer than normal (7 were at least 3.5 degrees F and 2 were more than 5.0 degrees F above normal). Precipitation totaled 6.12 in., 98% of normal (6.26 in.); snowfall totaled 5.2 in., compared to the normal of 13.8 in. The average wind speed during 1994 was 7.3 mph, 0.4 mph below normal (7.7 mph). The peak gust during the year was 52 mph from the south-southwest on February 13. There were 29 days with peak gusts ≥40 mph, compared to a yearly average of 26

  9. Climatology 2011: An MLS and Sonde Derived Ozone Climatology for Satellite Retrieval Algorithms

    Science.gov (United States)

    McPeters, Richard D.; Labow, Gordon J.

    2012-01-01

    The ozone climatology used as the a priori for the version 8 Solar Backscatter Ultraviolet (SBUV) retrieval algorithms has been updated. The Microwave Limb Sounder (MLS) instrument on Aura has excellent latitude coverage and measures ozone daily from the upper troposphere to the lower mesosphere. The new climatology consists of monthly average ozone profiles for ten degree latitude zones covering pressure altitudes from 0 to 65 km. The climatology was formed by combining data from Aura MLS (2004-2010) with data from balloon sondes (1988-2010). Ozone below 8 km (below 12 km at high latitudes) is based on balloons sondes, while ozone above 16 km (21 km at high latitudes) is based on MLS measurements. Sonde and MLS data are blended in the transition region. Ozone accuracy in the upper troposphere is greatly improved because of the near uniform coverage by Aura MLS, while the addition of a large number of balloon sonde measurements improves the accuracy in the lower troposphere, in the tropics and southern hemisphere in particular. The addition of MLS data also improves the accuracy of climatology in the upper stratosphere and lower mesosphere. The revised climatology has been used for the latest reprocessing of SBUV and TOMS satellite ozone data.

  10. A novel tropopause-related climatology of ozone profiles

    Science.gov (United States)

    Sofieva, V. F.; Tamminen, J.; Kyrölä, E.; Mielonen, T.; Veefkind, P.; Hassler, B.; Bodeker, G. E.

    2014-01-01

    A new ozone climatology, based on ozonesonde and satellite measurements, spanning the altitude region between the earth's surface and ~60 km is presented (TpO3 climatology). This climatology is novel in that the ozone profiles are categorized according to calendar month, latitude and local tropopause heights. Compared to the standard latitude-month categorization, this presentation improves the representativeness of the ozone climatology in the upper troposphere and the lower stratosphere (UTLS). The probability distribution of tropopause heights in each latitude-month bin provides additional climatological information and allows transforming/comparing the TpO3 climatology to a standard climatology of zonal mean ozone profiles. The TpO3 climatology is based on high-vertical-resolution measurements of ozone from the satellite-based Stratospheric Aerosol and Gas Experiment II (in 1984 to 2005) and from balloon-borne ozonesondes from 1980 to 2006. The main benefits of the TpO3 climatology are reduced standard deviations on climatological ozone profiles in the UTLS, partial characterization of longitudinal variability, and characterization of ozone profiles in the presence of double tropopauses. The first successful application of the TpO3 climatology as a priori in ozone profile retrievals from Ozone Monitoring Instrument on board the Earth Observing System (EOS) Aura satellite shows an improvement of ozone precision in UTLS of up to 10% compared with the use of conventional climatologies. In addition to being advantageous for use as a priori in satellite retrieval algorithms, the TpO3 climatology might be also useful for validating the representation of ozone in climate model simulations.

  11. A novel tropopause-related climatology of ozone profiles

    Directory of Open Access Journals (Sweden)

    V. F. Sofieva

    2013-08-01

    Full Text Available A new ozone climatology, based on ozonesonde and satellite measurements, spanning the altitude region between the Earth's surface and ~60 km is presented (TpO3 climatology. This climatology is novel in that the ozone profiles are categorized according to calendar month, latitude and local tropopause heights. Compared to the standard latitude-month categorization, this presentation improves the representativeness of the ozone climatology in the upper troposphere and the lower stratosphere (UTLS. The probability distribution of tropopause heights in each latitude-month bin provides additional climatological information and allows transforming/comparing the TpO3 climatology to a standard climatology of zonally mean ozone profiles. The TpO3 climatology is based on high-vertical-resolution measurements of ozone from the satellite-based Stratospheric Aerosol and Gas Experiment II (in 1984 to 2005 and from balloon-borne ozonesondes in 1980 to 2006. The main benefits of the TpO3 climatology are reduced standard deviations on climatological ozone profiles in the UTLS, partial characterization of longitudinal variability, and characterization of ozone profiles in the presence of double tropopauses. The first successful application of the TpO3 climatology as a priori in ozone profiles retrievals from Ozone Monitoring Instrument on board the EOS-Aura satellite shows an improvement of ozone precision in UTLS of up to 10% compared with the use of conventional climatologies. In addition to being advantageous for use as a priori in satellite retrieval algorithms, the TpO3 climatology might be also useful for validating the representation of ozone in climate model simulations.

  12. NASA GLDAS Evapotranspiration Data and Climatology

    Science.gov (United States)

    Rui, Hualan; Beaudoing, Hiroko Kato; Teng, William L.; Vollmer, Bruce; Rodell, Matthew

    2012-01-01

    Evapotranspiration (ET) is the water lost to the atmosphere by evaporation and transpiration. ET is a shared component in the energy and water budget, therefore, a critical variable for global energy and water cycle and climate change studies. However, direct ET measurements and data acquisition are difficult and expensive, especially at the global level. Therefore, modeling is one common alternative for estimating ET. With the goal to generate optimal fields of land surface states and fluxes, the Global Land Data Assimilation System (GLDAS) has been generating quality-controlled, spatially and temporally consistent, terrestrial hydrologic data, including ET and other variables that affect evaporation and transpiration, such as temperature, precipitation, humidity, wind, soil moisture, heat flux, and solar radiation. This poster presents the long-term ET climatology (mean and monthly), derived from the 61-year GLDAS-2 monthly 1.0 deg x 1.0 deg. NOAH model Experiment-1 data, and describes the basic characteristics of spatial and seasonal variations of the climatology. The time series of GLDAS-2 precipitation and radiation, and ET are also discussed to show the improvement of GLDAS-2 forcing data and model output over those from GLDAS-1.

  13. A climatological analysis of Saharan cyclones

    Science.gov (United States)

    Ammar, K.; El-Metwally, Mossad; Almazroui, Mansour; Abdel Wahab, M. M.

    2014-07-01

    In this study, the climatology of Saharan cyclones is presented in order to understand the Saharan climate, its variability and its changes. This climatology includes an analysis of seasonal and interannual variations, the identification and classification of cyclone tracks, and a presentation of their chief characteristics. The data used are drawn from the 1980-2009, 2.5° × 2.5°, NCEP/NCAR reanalysis (NNRP I) dataset. It is found that cyclone numbers increase in September-October-November (SON) at 4.9 cyclones per decade, while they decrease in June-July-August at 12.3 cyclones per decade. The identification algorithm constructed 562 tracks, which are categorized into 12 distinct clusters. Around 75 % of the Saharan cyclones originate south of the Atlas Mountains. The percentage of tracks that move over the Sahara is around 48 %. The eastern Mediterranean receives 27 % of the Saharan tracks, while the western basin receives only 17 and 8 % of all the Saharan cyclones decay over the Arabian Peninsula. The maximum cyclonic activity occurs in April. There is a general decrease in the number of tracks in all categories between 1993 and 2009, compared with the period between 1980 and 1992. About 72 % of the Saharan cyclones do not live more than 3 days, and about 80 % of the cyclones in the tracks never reach central pressures 1,000 hPa during their lifetimes. The maximum deepening in the tracks occurs over the western Mediterranean and over northern Algeria.

  14. A climatology of visible surface reflectance spectra

    Science.gov (United States)

    Zoogman, Peter; Liu, Xiong; Chance, Kelly; Sun, Qingsong; Schaaf, Crystal; Mahr, Tobias; Wagner, Thomas

    2016-09-01

    We present a high spectral resolution climatology of visible surface reflectance as a function of wavelength for use in satellite measurements of ozone and other atmospheric species. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is planned to measure backscattered solar radiation in the 290-740 nm range, including the ultraviolet and visible Chappuis ozone bands. Observation in the weak Chappuis band takes advantage of the relative transparency of the atmosphere in the visible to achieve sensitivity to near-surface ozone. However, due to the weakness of the ozone absorption features this measurement is more sensitive to errors in visible surface reflectance, which is highly variable. We utilize reflectance measurements of individual plant, man-made, and other surface types to calculate the primary modes of variability of visible surface reflectance at a high spectral resolution, comparable to that of TEMPO (0.6 nm). Using the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirection Reflectance Distribution Function (BRDF)/albedo product and our derived primary modes we construct a high spatial resolution climatology of wavelength-dependent surface reflectance over all viewing scenes and geometries. The Global Ozone Monitoring Experiment-2 (GOME-2) Lambertian Equivalent Reflectance (LER) product provides complementary information over water and snow scenes. Preliminary results using this approach in multispectral ultraviolet+visible ozone retrievals from the GOME-2 instrument show significant improvement to the fitting residuals over vegetated scenes.

  15. Precipitation Climatology on Titan-like Exomoons.

    Science.gov (United States)

    Tokano, Tetsuya

    2015-06-01

    The availability of liquid water on the surface on Earth's continents in part relies on the precipitation of water. This implies that the habitability of exomoons has to consider not only the surface temperature and atmospheric pressure for the presence of liquid water, but also the global precipitation climatology. This study explores the sensitivity of the precipitation climatology of Titan-like exomoons to these moons' orbital configuration using a global climate model. The precipitation rate primarily depends on latitude and is sensitive to the planet's obliquity and the moon's rotation rate. On slowly rotating moons the precipitation shifts to higher latitudes as obliquity is increased, whereas on quickly rotating moons the latitudinal distribution does not strongly depend on obliquity. Stellar eclipse can cause a longitudinal variation in the mean surface temperature and surface pressure between the subplanetary and antiplanetary side if the planet's obliquity and the moon's orbital distance are small. In this particular condition the antiplanetary side generally receives more precipitation than the subplanetary side. However, precipitation on exomoons with dense atmospheres generally occurs at any longitude in contrast to tidally locked exoplanets. PMID:25796390

  16. Up-to-date probabilistic temperature climatologies

    International Nuclear Information System (INIS)

    With ongoing global warming, climatologies based on average past temperatures are increasingly recognized as imperfect guides for current conditions, yet there is no consensus on alternatives. Here, we compare several approaches to deriving updated expected values of monthly mean temperatures, including moving average, exponentially weighted moving average, and piecewise linear regression. We go beyond most previous work by presenting updated climate normals as probability distributions rather than only point estimates, enabling estimation of the changing likelihood of hot and cold extremes. We show that there is a trade-off between bias and variance in these approaches, but that bias can be mitigated by an additive correction based on a global average temperature series, which has much less interannual variability than a single-station series. Using thousands of monthly temperature time series from the Global Historical Climatology Network (GHCN), we find that the exponentially weighted moving average with a timescale of 15 years and global bias correction has good overall performance in hindcasting temperatures over the last 30 years (1984–2013) compared with the other methods tested. Our results suggest that over the last 30 years, the likelihood of extremely hot months (above the 99th percentile of the temperature probability distribution as of the early 1980s) has increased more than fourfold across the GHCN stations, whereas the likelihood of very cold months (under the 1st percentile) has decreased by over two-thirds. (letter)

  17. Long-term changes in climatological calendar

    International Nuclear Information System (INIS)

    Trends in time series of climatic seasons in Tartu, Estonia, during 1891-1995 are analysed using regression analysis. Two intermediate seasons between autumn and winter (late autumn, early winter), and two ones between winter and spring (late winter and early spring) are determined. The climatic seasons correspond quite well to individual stages of annual cycling of nature. Results of linear regression analysis demonstrate changes in climatological calendar reflecting the influence of global warming. Climatic seasons of spring period have moved to earlier time, and seasons of autumn period to later time. Statistically significant trends were observed for beginning date of early spring (12 days earlier), summer (11 days earlier) and late autumn (8 days later). Beginning date of winter has shifted 12 days later. Duration of summer season has increased by two weeks and duration of winter season has decreased by the same time. (author)

  18. The Global Climatology Network Precipitation data

    International Nuclear Information System (INIS)

    Several years ago, in response to growing concern about global climate change, the US National Climatic Data Center and the Carbon Dioxide Information Analysis Center undertook an effort to create a baseline global land surface climate data set called the Global Historical Climatology Network (GHCN, Vose et al., 1992). GHCN was created by merging several large existing climate data sets into one data base. Fifteen separate data sets went into the creation of the GHCN version 1.0. GHCN version 1.0 was released in 1992. It has 7,533 precipitation stations, but the number of stations varies with time. A slight majority (55%) have records in excess of 50 years, and a significant proportion (13%) have records in excess of 100 years. The longest period of record for any given station is 291 years (1697--1987 for Kew, United Kingdom)

  19. Climatology of POLDER/PARASOL cloud properties

    Science.gov (United States)

    Parol, F.; Riedi, J.; Vanbauce, C.; Cornet, C.; Zeng, S.; Thieuleux, F.; Henriot, N.

    2013-05-01

    Since December 2004 the CNES PARASOL (Polarization and Anisotropy of Reflectances for Atmospheric Science coupled with Observations from a Lidar) mission has been flying in the A-Train constellation. More than seven years of data have been routinely acquired and processed by the PARASOL/POLDER ground segment (CNES) and by ICARE Data Center in Lille, France. PARASOL's unique spectral, directional and polarization capabilities give powerful constraints to the cloud retrieval scheme. They allow derivation of classical cloud properties (amount, optical depth, altitude or pressure, albedo) with state of the art performance but also provide original information (thermodynamic phase, angular variability of properties, heterogeneity parameter, etc.). Climatology of cloud fraction and cloud optical thickness have been realized over the 2005-2011 period. Some results and comparisons to MODIS are shown for the year 2008.

  20. Lightning climatology in the Congo Basin

    Science.gov (United States)

    Soula, S.; Kasereka, J. Kigotsi; Georgis, J. F.; Barthe, C.

    2016-09-01

    The lightning climatology of the Congo Basin including several countries of Central Africa is analysed in detail for the first time. It is based on data from the World Wide Lightning Location Network (WWLLN), for the period from 2005 to 2013. A comparison of these data with Lightning Imaging Sensor (LIS) data for the same period shows the relative detection efficiency of the WWLLN (DE) in the 2500 km × 2500 km region increases from about 1.70% in the beginning of the period to 5.90% in 2013, and it is in agreement with previous results for other regions of the world. However, the increase of DE is not uniform over the whole region. The average monthly flash rate describes an annual cycle with a strong activity from October to March and a low one from June to August, associated with the ITCZ migration but not exactly symmetrical on both sides of the equator. The zonal distribution of the lightning flashes exhibits a maximum between 1°S and 2°S and about 56% of the flashes are located south of the equator in the 10°S-10°N interval. The diurnal evolution of the flash rate has a maximum between 1400 and 1700 UTC, according to the reference year. The annual flash density and number of stormy days show a sharp maximum localized in the eastern part of Democratic Republic of Congo (DRC) regardless of the reference year and the period of the year. These maxima reach 12.86 fl km- 2 and 189 days, respectively, in 2013, and correspond to a very active region located at the rear of the Virunga mountain range at altitudes that exceed 3000 m. The presence of these mountains plays a role in the thunderstorm development along the year. The estimation of this local maximum of the lightning density by taking into account the DE, leads to a value consistent with that of the global climatology by Christian et al. (2003).

  1. An empirical framework for tropical cyclone climatology

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Nam-Young [Korea Meteorological Administration, Seoul (Korea, Republic of); Florida State University, Tallahassee, FL (United States); Elsner, James B. [Florida State University, Tallahassee, FL (United States)

    2012-08-15

    An empirical approach for analyzing tropical cyclone climate is presented. The approach uses lifetime-maximum wind speed and cyclone frequency to induce two orthogonal variables labeled ''activity'' and ''efficiency of intensity''. The paired variations of activity and efficiency of intensity along with the opponent variations of frequency and intensity configure a framework for evaluating tropical cyclone climate. Although cyclone activity as defined in this framework is highly correlated with the commonly used exponent indices like accumulated cyclone energy, it does not contain cyclone duration. Empirical quantiles are used to determine threshold intensity levels, and variant year ranges are used to find consistent trends in tropical cyclone climatology. In the western North Pacific, cyclone activity is decreasing despite increases in lifetime-maximum intensity. This is due to overwhelming decreases in cyclone frequency. These changes are also explained by an increasing efficiency of intensity. The North Atlantic shows different behavior. Cyclone activity is increasing due to increasing frequency and, to a lesser extent, increasing intensity. These changes are also explained by a decreasing efficiency of intensity. Tropical cyclone trends over the North Atlantic basin are more consistent over different year ranges than tropical cyclone trends over the western North Pacific. (orig.)

  2. Int'l meeting on statistical climatology convenes in Beijing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Sponsored by the CAS Institute of Atmospheric Physics (IAP), the 10th International Meeting on Statistical Climatology, (10IMSC) was held from 20 to 24 August in Beijing, bringing together nearly 120 participants from about 30 countries and regions.

  3. Teaching a Model-based Climatology Using Energy Balance Simulation.

    Science.gov (United States)

    Unwin, David

    1981-01-01

    After outlining the difficulties of teaching climatology within an undergraduate geography curriculum, the author describes and evaluates the use of a computer assisted simulation to model surface energy balance and the effects of land use changes on local climate. (AM)

  4. Global Precipitation Climatology Project (GPCP) - Pentad, Version 2.2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Precipitation Climatology Project (GPCP) comprises a total of 27 products. The Version 2.2 Pentad product covers the period January 1979 to the present,...

  5. Historical Climatology In Europe. The State Of The Art

    Energy Technology Data Exchange (ETDEWEB)

    Brazdil, R. [Institute of Geography, Masaryk University, Kotlarska 2, CZ-611 37 Brno (Czech Republic); Pfister, C. [Institute of History/NCCR Climate, University of Bern, Unitobler, CH-3000 Bern 9 (Switzerland); Wanner, H.; Luterbacher, J. [NCCR Climate, University of Bern, Hallerstrasse 12, CH-3012 Bern (Switzerland); Von Storch, H. [GKSS-Research-Center, Max Planck Strasse 1, D-21502 Geesthacht (Germany)

    2005-06-01

    This paper discusses the state of European research in historical climatology. This field of science and an overview of its development are described in detail. Special attention is given to the documentary evidence used for data sources, including its drawbacks and advantages. Further, methods and significant results of historical-climatological research, mainly achieved since 1990, are presented. The main focus concentrates on data, methods, definitions of the 'Medieval Warm Period' and the 'Little Ice Age', synoptic interpretation of past climates, climatic anomalies and natural disasters, and the vulnerability of economies and societies to climate as well as images and social representations of past weather and climate. The potential of historical climatology for climate modelling research is discussed briefly. Research perspectives in historical climatology are formulated with reference to data, methods, interdisciplinarity and impacts.

  6. Global Precipitation Climatology Project (GPCP) - Daily, Version 1.2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Precipitation Climatology Project (GPCP) comprises a total of 27 products. The Version 1.2 Daily product covers the period October 1998 to the present,...

  7. Global Historical Climatology Network - Daily (GHCN-Daily), Version 3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Historical Climatology Network - Daily (GHCN-Daily) dataset integrates daily climate observations from approximately 30 different data sources. Version 3...

  8. Global Historical Climatology Network - Monthly (GHCN-M), Version 3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Since the early 1990s the Global Historical Climatology Network-Monthly (GHCN-M) dataset has been an internationally recognized source of data for the study of...

  9. Global Precipitation Climatology Project (GPCP) - Monthly, Version 2.2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Precipitation Climatology Project (GPCP) comprises a total of 27 products with the two primary products being the monthly satellite-gauge and associated...

  10. Hanford Site Climatological Summary 2004 with Historical Data

    Energy Technology Data Exchange (ETDEWEB)

    Hoitink, Dana J.; Burk, Kenneth W.; Ramsdell, James V.; Shaw, William J.

    2005-06-03

    This document presents the climatological data measured on the DOE Hanford Site for calendar year 2004. This report contains updated historical information for temperature, precipitation, wind, and normal and extreme values of temperature, and precipitation.

  11. Snow density climatology across the former USSR

    Directory of Open Access Journals (Sweden)

    X. Zhong

    2013-07-01

    Full Text Available Snow density is one of the basic properties used to describe snow cover characteristics, and it is a key factor for retrieving snow depth and snow water equivalent, which are critical for water resources assessment and modeling inputs. In this study, we used long-term data from ground-based measurements to investigate snow density climatology and its spatiotemporal variations across the former Soviet Union (USSR from 1966 to 2008. The results showed that the long-term monthly mean snow density was approximately 0.194 ± 0.046 g cm−3 over the study area. The maximum and minimum monthly mean snow density was ∼ 0.295 g cm−3 in June, and 0.135 g cm−3 in October, respectively. Maritime snow had the highest monthly mean snow density, while taiga snow had the lowest. The higher values of monthly snow density were mainly located in the European regions of the former USSR, in Arctic Russia, and in some regions of the Russian Far East, and the lower snow density occurred in central Siberia. Significant increasing trends of snow density from September through June of the next year were observed, however, the rate of the increase varied with different snow classes. The long-term (1966–2008 monthly and annual mean snow densities had significant decreasing trends, especially during the autumn months. Spatially, significant positive trends in monthly mean snow density lay in the southwestern areas of the former USSR in November and December and gradually expanded in Russia from February through April. Significant negative trends mainly lay in the European Russia and the southern Russia. Snow density decreased with elevation, at about 0.004 g cm−3 per 100 m increase in elevation. This same relationship existed for all snow classes except for maritime and ephemeral snow.

  12. Fog and dew climatology over Hisar, India

    International Nuclear Information System (INIS)

    In many arid and semi-arid areas, pumped ground water and the water from streams, rivers and reservoirs is no longer sufficient to cover the ever increasing water demand. Therefore new interest in 'marginal' water resources like fog and dew harvesting are to be developed after studying climatology of these parameters in a region. The observations on dew and fog events recorded at Hisar, representing semi-arid region of India during winter season (October to March) for the period 1980 to 2005 have been analyzed. The total annual dew amount in winter season ranged between 33 mm (1987-88) and 79 mm (1981-82) during the period under study. The seasonal dewfall showed a decreasing trend of 1.4 mm during the period under investigation. Average maximum dew events (26.1) were recorded during November and average minimum dew events were recorded in February. In a particular season, the highest dew events (168) were observed during the winter seasons of 1982-83 and 1983-84, whereas, the minimum number of dew events (97) was reported during 1998-99. Interestingly, an increasing trend (1.3 day/season) in occurrence of fog events was seen. Average maximum foggy events (8.7) recorded in a month were observed in January. In a particular season, the maximum foggy events (41) were recorded during 2002-03 and the minimum (2) during 1983-84. To achieve the objective of alternate source of water and to assess the impact of dew and fog on agricultural crops for their growth and development, inputs from various specialized disciplines and allied sciences engaged in meteorological applications along with forecasting skills from non scientific quarters are needed to predict the weather parameter accurately, thus the active cooperation between meteorological/remote sensing agencies, agricultural organizations and farming community is needed for sustainable agricultural development in scarce/limited water availability regions. (author)

  13. Estimating Climatological Bias Errors for the Global Precipitation Climatology Project (GPCP)

    Science.gov (United States)

    Adler, Robert; Gu, Guojun; Huffman, George

    2012-01-01

    A procedure is described to estimate bias errors for mean precipitation by using multiple estimates from different algorithms, satellite sources, and merged products. The Global Precipitation Climatology Project (GPCP) monthly product is used as a base precipitation estimate, with other input products included when they are within +/- 50% of the GPCP estimates on a zonal-mean basis (ocean and land separately). The standard deviation s of the included products is then taken to be the estimated systematic, or bias, error. The results allow one to examine monthly climatologies and the annual climatology, producing maps of estimated bias errors, zonal-mean errors, and estimated errors over large areas such as ocean and land for both the tropics and the globe. For ocean areas, where there is the largest question as to absolute magnitude of precipitation, the analysis shows spatial variations in the estimated bias errors, indicating areas where one should have more or less confidence in the mean precipitation estimates. In the tropics, relative bias error estimates (s/m, where m is the mean precipitation) over the eastern Pacific Ocean are as large as 20%, as compared with 10%-15% in the western Pacific part of the ITCZ. An examination of latitudinal differences over ocean clearly shows an increase in estimated bias error at higher latitudes, reaching up to 50%. Over land, the error estimates also locate regions of potential problems in the tropics and larger cold-season errors at high latitudes that are due to snow. An empirical technique to area average the gridded errors (s) is described that allows one to make error estimates for arbitrary areas and for the tropics and the globe (land and ocean separately, and combined). Over the tropics this calculation leads to a relative error estimate for tropical land and ocean combined of 7%, which is considered to be an upper bound because of the lack of sign-of-the-error canceling when integrating over different areas with a

  14. Eight Year Climatologies from Observational (AIRS) and Model (MERRA) Data

    Science.gov (United States)

    Hearty, Thomas; Savtchenko, Andrey; Won, Young-In; Theobalk, Mike; Vollmer, Bruce; Manning, Evan; Smith, Peter; Ostrenga, Dana; Leptoukh, Greg

    2010-01-01

    We examine climatologies derived from eight years of temperature, water vapor, cloud, and trace gas observations made by the Atmospheric Infrared Sounder (AIRS) instrument flying on the Aqua satellite and compare them to similar climatologies constructed with data from a global assimilation model, the Modern Era Retrospective-Analysis for Research and Applications (MERRA). We use the AIRS climatologies to examine anomalies and trends in the AIRS data record. Since sampling can be an issue for infrared satellites in low earth orbit, we also use the MERRA data to examine the AIRS sampling biases. By sampling the MERRA data at the AIRS space-time locations both with and without the AIRS quality control we estimate the sampling bias of the AIRS climatology and the atmospheric conditions where AIRS has a lower sampling rate. While the AIRS temperature and water vapor sampling biases are small at low latitudes, they can be more than a few degrees in temperature or 10 percent in water vapor at higher latitudes. The largest sampling biases are over desert. The AIRS and MERRA data are available from the Goddard Earth Sciences Data and Information Services Center (GES DISC). The AIRS climatologies we used are available for analysis with the GIOVANNI data exploration tool. (see, http://disc.gsfc.nasa.gov).

  15. Towards a generalization procedure for WRF mesoscale wind climatologies

    DEFF Research Database (Denmark)

    Hahmann, Andrea N.; Casso, P.; Campmany, E.;

    We present a method for generalizing wind climatologies generated from mesoscale model output (e.g. the Weather, Research and Forecasting (WRF) model.) The generalization procedure is based on Wind Atlas framework of WAsP and KAMM/WAsP, and been extensively in wind resources assessment in DTU Wind...... generalized wind climatologies estimated by the microscale model WAsP and the methodology presented here. For the Danish wind measurements the mean absolute error in the ‘raw’ wind speeds is 9.2%, while the mean absolute error in the generalized wind speeds is 4.1%. The generalization procedure has been...

  16. Some Spatial Aspects of Southeastern United States Climatology.

    Science.gov (United States)

    Soule, Peter T.

    1998-01-01

    Focuses on the climatology of an eight-state region in the southern and southeastern United States. Discusses general controls of climate and spatial patterns of various climatic averages. Examines mapped extremes as a means of fostering increased awareness of the variability that exists for climatic conditions in the region. (CMK)

  17. Are climatological correlations with the Hale double sunspot cycle meaningful

    International Nuclear Information System (INIS)

    A sunspot cycle which may have been subject to a predicted phase reversal between 1800 and 1880 A.D. is discussed. Several climatological parameters normally correlated with this cycle are examined and do not exhibit a corresponding phase reversal during this period. It is proposed that this apparent discrepency can be resolved by suitable observations during the upcoming half decade

  18. Biologically effective surface UV climatology at Rome and Aosta, Italy

    Science.gov (United States)

    Siani, Anna Maria; Modesti, Sarah; Casale, Giuseppe Rocco; Diemoz, Henri; Colosimo, Alfredo

    2013-05-01

    Given the beneficial and harmful effects of UV radiation on human health, our study aims to provide a characterization of erythemal and vitamin D dose rates at two Italian sites, Rome and Aosta, subject to quite different environmental conditions. Based on the respective UV climatologies, exposure times needed to induce erythema or vitamin D photoproduction are provided as a function of the UV index.

  19. The modification of the typhoon rainfall climatology model in Taiwan

    Directory of Open Access Journals (Sweden)

    C.-S. Lee

    2013-01-01

    Full Text Available This study is focused on the modification of a typhoon rainfall climatological model, by using the dataset up to 2006 and including data collected from rain gauge stations established after the 921 earthquake (1999. Subsequently, the climatology rainfall models for westward- and northward-moving typhoons are established by using the typhoon track classification from the Central Weather Bureau. These models are also evaluated and examined using dependent cases collected between 1989 and 2006 and independent cases collected from 2007 to 2011. For the dependent cases, the average total rainfall at all rain gauge stations forecasted using the climatology rainfall models for westward- (W-TRCM12 and northward-moving (N-TRCM12 typhoons is superior to that obtained using the original climatological model (TRCM06. Model W-TRCM12 significantly improves the precipitation underestimation of model TRCM06. The independent cases show that model W-TRCM12 provides better accumulated rainfall forecasts and distributions than model TRCM06. A climatological model for accompanied northeastern monsoons (A-TRCM12 for special typhoon types has also been established. The current A-TRCM12 model only contains five historical cases and various typhoon combinations can cause precipitation in different regions. Therefore, precipitation is likely to be significantly overestimated and high false alarm ratios are likely to occur in specific regions. For example, model A-TRCM12 significantly overestimates the rainfall forecast for Typhoon Mitag, an independent case from 2007. However, it has a higher probability of detection than model TRCM06. From a disaster prevention perspective, a high probability of detection is much more important than a high false alarm ratio. The modified models can contribute significantly to operational forecast.

  20. Clear sky atmosphere at cm-wavelengths from climatology data

    CERN Document Server

    Lew, Bartosz

    2015-01-01

    We utilise ground-based, balloon-born and satellite climatology data to reconstruct site and season-dependent vertical profiles of precipitable water vapour (PWV). We use these profiles to numerically solve radiative transfer through the atmosphere, and derive atmospheric brightness temperature ($T_{\\rm atm}$) and optical depth ($\\tau$) at the centimetre wavelengths. We validate the reconstruction by comparing the model column PWV, with photometric measurements of PWV, performed in the clear sky conditions towards the Sun. Based on the measurements, we devise a selection criteria to filter the climatology data to match the PWV levels to the expectations of the clear sky conditions. We apply the reconstruction to the location of the Polish 32-metre radio telescope, and characterise $T_{\\rm atm}$ and $\\tau$ year-round, at selected frequencies. We also derive the zenith distance dependence for these parameters, and discuss shortcomings of using planar, single-layer, and optically thin atmospheric model approxima...

  1. The Global Precipitation Climatology Project (GPCP) Combined Precipitation Dataset

    Science.gov (United States)

    Huffman, George J.; Adler, Robert F.; Arkin, Philip; Chang, Alfred; Ferraro, Ralph; Gruber, Arnold; Janowiak, John; McNab, Alan; Rudolf, Bruno; Schneider, Udo

    1997-01-01

    The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global, monthly precipitation dataset covering the period July 1987 through December 1995. The primary product in the dataset is a merged analysis incorporating precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit -satellite infrared data, and rain gauge observations. The dataset also contains the individual input fields, a combination of the microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5 deg x 2.5 deg latitude-longitude global grids. Preliminary analyses show general agreement with prior studies of global precipitation and extends prior studies of El Nino-Southern Oscillation precipitation patterns. At the regional scale there are systematic differences with standard climatologies.

  2. Climatologies at high resolution for the Earth land surface areas

    CERN Document Server

    Karger, Dirk Nikolaus; Böhner, Jürgen; Kawohl, Tobias; Kreft, Holger; Soria-Auza, Rodrigo Wilber; Zimmermann, Niklaus; Linder, H Peter; Kessler, Michael

    2016-01-01

    High resolution information of climatic conditions is essential to many application in environmental sciences. Here we present the CHELSA algorithm to downscale temperature and precipitation estimates from the European Centre for Medium-Range Weather Forecast (ECMWF) climatic reanalysis interim (ERA-Interim) to a high resolution of 30 arc sec. The algorithm for temperature is based on a statistical downscaling of atmospheric temperature from the ERA-Interim climatic reanalysis. The precipitation algorithm incorporates orographic predictors such as wind fields, valley exposition, and boundary layer height, and a bias correction using Global Precipitation Climatology Center (GPCC) gridded and Global Historical Climate Network (GHCN) station data. The resulting data consist of a monthly temperature and precipitation climatology for the years 1979-2013. We present a comparison of data derived from the CHELSA algorithm with two other high resolution gridded products with overlapping temporal resolution (Tropical R...

  3. Clear sky atmosphere at cm-wavelengths from climatology data

    OpenAIRE

    Lew, Bartosz; Uscka-Kowalkowska, Joanna

    2015-01-01

    We utilise ground-based, balloon-borne and satellite climatology data to reconstruct site and season-dependent vertical profiles of precipitable water vapour (PWV). We use these profiles to solve radiative transfer through the atmosphere, and derive atmospheric brightness temperature ($T_{\\rm atm}$) and optical depth ($\\tau$) at centimetre wavelengths. We validate the reconstruction by comparing the model column PWV with photometric measurements of PWV, performed in clear sky conditions point...

  4. Envisat MIPAS measurements of CFC-11: retrieval, validation, and climatology

    Directory of Open Access Journals (Sweden)

    L. Hoffmann

    2008-03-01

    Full Text Available From July 2002 to March 2004 the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS aboard the European Space Agency's Environmental Satellite (Envisat measured nearly continuously mid infrared limb radiance spectra. These measurements are utilised to retrieve the global distribution of the chlorofluorocarbon CFC-11 by applying a new fast forward model for Envisat MIPAS and an accompanying optimal estimation retrieval processor. A detailed analysis shows that the total retrieval errors of the individual CFC-11 volume mixing ratios are typically below 10% and that the systematic components are dominating. Contribution of a priori information to the retrieval results are less than 5 to 10%. The vertical resolution of the observations is about 3 to 4 km. The data are successfully validated by comparison with several other space experiments, an air-borne in-situ instrument, measurements from ground-based networks, and independent Envisat MIPAS analyses. The retrieval results from 425 000 Envisat MIPAS limb scans are compiled to provide a new climatological data set of CFC-11. The climatology shows significantly lower CFC-11 abundances in the lower stratosphere compared with the Reference Atmospheres for MIPAS (RAMstan V3.1 climatology. Depending on the atmospheric conditions the differences between the climatologies are up to 30 to 110 ppt (45 to 150% at 19 to 27 km altitude. Additionally, time series of CFC-11 mean abundance and variability for five latitudinal bands are presented. The observed CFC-11 distributions can be explained by the residual mean circulation and large-scale eddy-transports in the upper troposphere and lower stratosphere. The new CFC-11 data set is well suited for further scientific studies.

  5. Envisat MIPAS measurements of CFC-11: retrieval, validation, and climatology

    Directory of Open Access Journals (Sweden)

    L. Hoffmann

    2008-07-01

    Full Text Available From July 2002 to March 2004 the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS aboard the European Space Agency's Environmental Satellite (Envisat measured nearly continuously mid infrared limb radiance spectra. These measurements are utilised to retrieve the global distribution of the chlorofluorocarbon CFC-11 by applying a new fast forward model for Envisat MIPAS and an accompanying optimal estimation retrieval processor. A detailed analysis shows that the total retrieval errors of the individual CFC-11 volume mixing ratios are typically below 10% in the altitude range 10 to 25 km and that the systematic components dominate. Contribution of a priori information to the retrieval results are less than 5 to 10% and the vertical resolution of the observations is about 3 to 4 km in the same vertical range. The data are successfully validated by comparison with several other space experiments, an air-borne in-situ instrument, measurements from ground-based networks, and independent Envisat MIPAS analyses. The retrieval results from 425 000 Envisat MIPAS limb scans are compiled to provide a new climatological data set of CFC-11. The climatology shows significantly lower CFC-11 abundances in the lower stratosphere compared with the Reference Atmospheres for MIPAS (RAMstan V3.1 climatology. Depending on the atmospheric conditions the differences between the climatologies are up to 30 to 110 ppt (45 to 150% at 19 to 27 km altitude. Additionally, time series of CFC-11 mean abundance and variability for five latitudinal bands are presented. The observed CFC-11 distributions can be explained by the residual mean circulation and large-scale eddy-transports in the upper troposphere and lower stratosphere. The new CFC-11 data set is well suited for further scientific studies.

  6. Scintillations climatology over low latitudes: statistical analysis and WAM modelling

    OpenAIRE

    Spogli, Luca; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Alfonsi, Lucilla; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Materassi, Massimo; Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche; Wernik, Andrzej W.; Space Research Center, Polish Academy of Sciences

    2010-01-01

    Attempts of reconstructing the spatial and temporal distribution of the ionospheric irregularities have been conducted developing a scintillation “climatology” technique, which was very promising in characterizing the plasma conditions triggering L-band scintillations at high latitudes ([1.],[2.]) and further analysis on bipolar high sampling rate (50 Hz) GPS data are currently in progress for deeper investigations. The core of the scintillation climatology technique is represente...

  7. LARGE SCALE WIND CLIMATOLOGICAL EXAMINATIONS OF WIND ENERGY UTILIZATION

    OpenAIRE

    ANDREA KIRCSI

    2008-01-01

    The aim of this article is to describe the particular field of climatology which analyzes air movement characteristics regarding utilization of wind for energy generation. The article describes features of wind energy potential available in Hungary compared to wind conditions in other areas of the northern quarter sphere in order to assist the wind energy use development in Hungary. Information on wind climate gives a solid basis for financial and economic decisions of stakeholders in the fie...

  8. Ozonesonde climatology between 1995 and 2009: description, evaluation and applications

    Directory of Open Access Journals (Sweden)

    S. Tilmes

    2011-10-01

    Full Text Available An ozone climatology based on ozone soundings for the last 15 years has been constructed for model evaluation and comparisons to other observations. Vertical ozone profiles for 41 stations around the globe have been compiled and averaged for the years 1980–1994 and 1995–2009. The climatology provides information about the median and the width of the ozone probability distribution function, as well as interannual variability of ozone between 1995 and 2009, in pressure and tropopause-referenced altitudes. In addition to single stations, regional aggregates are presented, combining stations with similar ozone characteristics. The Hellinger distance is introduced as a new diagnostic to compare the variability of ozone distributions within each region and used for model evaluation purposes. This measure compares not only the mean, but also the shape of distributions. The representativeness of regional aggregates is discussed using independent observations from surface stations and MOZAIC aircraft data. Ozone from all of these data sets show an excellent agreement within the range of the interannual variability, especially if a sufficient number of measurements are available, as is the case for West Europe. Within the climatology, a significant longitudinal variability of ozone in the troposphere and lower stratosphere in the northern mid- and high latitudes is found. The climatology is used to evaluate results from two model intercomparison activities, HTAP for the troposphere and CCMVal2 for the tropopause region and the stratosphere. HTAP ozone is in good agreement with observations in the troposphere within their range of uncertainty, but ozone peaks too early in the Northern Hemisphere spring. The strong gradients of ozone around the tropopause are less well captured by many models. Lower stratospheric ozone is overestimated for all regions by the multi-model mean of CCMVal2 models. Individual models also show major shortcomings in

  9. ENSO impact on simulated South American hydro-climatology

    Directory of Open Access Journals (Sweden)

    J. Stuck

    2006-01-01

    Full Text Available The variability of the simulated hydro-climatology of the WaterGAP Global Hydrology Model (WGHM is analysed. Main object of this study is the ENSO-driven variability of the water storage of South America. The horizontal model resolution amounts to 0.5 degree and it is forced with monthly climate variables for 1961-1995 of the Tyndall Centre Climate Research Unit dataset (CRU TS 2.0 as a representation of the observed climate state. Secondly, the model is also forced by the model output of a global circulation model, the ECHAM4-T42 GCM. This model itself is driven by observed monthly means of the global Sea Surface Temperatures (SST and the sea ice coverage for the period of 1903 to 1994 (GISST. Thus, the climate model and the hydrological model represent a realistic simulated realisation of the hydro-climatologic state of the last century. Since four simulations of the ECHAM4 model with the same forcing, but with different initial conditions are carried out, an analysis of variance (ANOVA gives an impression of the impact of the varying SST on the hydro-climatology, because the variance can be separated into a SST-explained and a model internal variability (noise. Also regional multivariate analyses, like Empirical Orthogonal Functions (EOF and Canonical Correlation Analysis (CCA provide information of the complex time-space variability. In particular the Amazon region and the South of Brazil are significantly influenced by the ENSO-variability, but also the Pacific coastal areas of Ecuador and Peru are affected. Additionally, different ENSO-indices, based on SST anomalies (e.g. NINO3.4, NINO1+2, and its influence on the South American hydro-climatology are analysed. Especially, the Pacific coast regions of Ecuador, Peru and Chile show a very different behaviour dependant on those indices.

  10. Mars Orbiter Camera climatology of textured dust storms

    Science.gov (United States)

    Guzewich, Scott D.; Toigo, Anthony D.; Kulowski, Laura; Wang, Huiqun

    2015-09-01

    We report the climatology of "textured dust storms", those dust storms that have visible structure on their cloud tops that are indicative of active dust lifting, as observed in Mars Daily Global Maps produced from Mars Orbiter Camera wide-angle images. Textured dust storms predominantly occur in the equinox seasons while both solstice periods experience a planet-wide "pause" in textured dust storm activity. These pauses correspond to concurrent decreases in global atmospheric dust opacity. Textured dust storms most frequently occur in Acidalia Planitia, Chryse Planitia, Arcadia Planitia, and Hellas basin. To examine the nature of the link between textured dust storms and atmospheric dust opacity, we compare the textured dust storm climatology with a record of atmospheric dust opacity and find a peak global correlation coefficient of approximately 0.5 with a lag of 20-40° in solar longitude in the opacity compared to the solar climatology. This implies that textured dust storms observed at 1400 local time by MOC are responsible for a large fraction of atmospheric dust opacity and that other mechanisms (e.g., dust devil lifting or storm-scale lifting not observed in this study) may supply a comparable amount of dust.

  11. Satellite derived aerosol optical depth climatology over Bangalore, India

    Science.gov (United States)

    Sreekanth, V.

    2013-06-01

    Climatological aerosol optical depths (AOD) over Bangalore, India have been examined to bring out the temporal heterogeneity in columnar aerosol characteristics. AOD values at 550 nm derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard NASA's Terra and Aqua satellites, for the period of 2002-2011 have been analyzed (independently) for the purpose. Frequency distributions of the AOD values are examined to infer the monthly mean values. Monthly and seasonal variations of AOD are investigated in the light of regional synoptic meteorology. Climatological monthly and seasonal mean Terra and Aqua AOD values exhibited similar temporal variation patterns. Monthly mean AOD values increased from January, peaks during May and thereafter (except for a secondary peak during July) fall off to reach a minimum during December. Monsoon season recorded the highest climatological seasonal mean AOD, while winter season recorded the lowest. AOD values show an overall increasing trend on a yearly basis, which was found mainly due to sustained increase in the seasonal averaged AOD during summer. The results obtained in the present study are compared with that of the earlier studies over the same location and also with AOD over various other Indian locations. Finally, the radiative and climatic impacts are discussed.

  12. Hanford Site climatological data summary 1995 with historical data

    Energy Technology Data Exchange (ETDEWEB)

    Hoitink, D.J.; Burk, K.W.

    1996-05-01

    This document presents the climatological data measured at the US Department of Energy`s Hanford Site for calendar year 1995. Pacific Northwest National Laboratory operates the Hanford Meteorology Station and the Hanford Meteorological Monitoring Network from which these data were collected. The information contained herein includes updated historical climatologies for temperature, precipitation, normal and extreme values of temperature and precipitation, and other miscellaneous meteorological parameters. Further, the data are adjunct to and update Hoitink and Burk (1994, 1995); however, Appendix B--Wind Climatology (1994) is excluded. 1995 was warmer than normal, averaging 54.7 F, 1.4 F above normal (53.3 F). For the 12-month period, 8 months were warmer than normal, and 4 were cooler than normal. 1995 was the wettest year on record. Precipitation totaled 12.31 in., 197% of normal (6.26 in.); snowfall totaled 7.7 in., compared to the normal of 13.8 in. The average wind speed during 1995 was 7.8 mph, 0.1 mph above normal (7.7 mph). The peak gust during the year was 61 mph from the south-southwest on December 12. There were 27 days with peak gusts {ge} 40 mph, compared to a yearly average of 26.

  13. Hanford Site climatological data summary 1995 with historical data

    International Nuclear Information System (INIS)

    This document presents the climatological data measured at the US Department of Energy's Hanford Site for calendar year 1995. Pacific Northwest National Laboratory operates the Hanford Meteorology Station and the Hanford Meteorological Monitoring Network from which these data were collected. The information contained herein includes updated historical climatologies for temperature, precipitation, normal and extreme values of temperature and precipitation, and other miscellaneous meteorological parameters. Further, the data are adjunct to and update Hoitink and Burk (1994, 1995); however, Appendix B--Wind Climatology (1994) is excluded. 1995 was warmer than normal, averaging 54.7 F, 1.4 F above normal (53.3 F). For the 12-month period, 8 months were warmer than normal, and 4 were cooler than normal. 1995 was the wettest year on record. Precipitation totaled 12.31 in., 197% of normal (6.26 in.); snowfall totaled 7.7 in., compared to the normal of 13.8 in. The average wind speed during 1995 was 7.8 mph, 0.1 mph above normal (7.7 mph). The peak gust during the year was 61 mph from the south-southwest on December 12. There were 27 days with peak gusts ≥ 40 mph, compared to a yearly average of 26

  14. Situational Lightning Climatologies for Central Florida: Phase IV: Central Florida Flow Regime Based Climatologies of Lightning Probabilities

    Science.gov (United States)

    Bauman, William H., III

    2009-01-01

    The threat of lightning is a daily concern during the warm season in Florida. Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. Previously, the Applied Meteorology Unit (AMU) calculated the gridded lightning climatologies based on seven flow regimes over Florida for 1-, 3- and 6-hr intervals in 5-, 10-, 20-, and 30-NM diameter range rings around the Shuttle Landing Facility (SLF) and eight other airfields in the National Weather Service in Melbourne (NWS MLB) county warning area (CWA). In this update to the work, the AMU recalculated the lightning climatologies for using individual lightning strike data to improve the accuracy of the climatologies. The AMU included all data regardless of flow regime as one of the stratifications, added monthly stratifications, added three years of data to the period of record and used modified flow regimes based work from the AMU's Objective Lightning Probability Forecast Tool, Phase II. The AMU made changes so the 5- and 10-NM radius range rings are consistent with the aviation forecast requirements at NWS MLB, while the 20- and 30-NM radius range rings at the SLF assist the Spaceflight Meteorology Group in making forecasts for weather Flight Rule violations during Shuttle landings. The AMU also updated the graphical user interface with the new data.

  15. A surface radiation climatology across two Meteosat satellite generations

    Science.gov (United States)

    Posselt, Rebekka; Müller, Richard; Trentmann, Jörg; Stöckli, Reto; Liniger, Mark A.

    2013-04-01

    Long term observations of the surface radiation budget are essential for climate monitoring, for climate model evaluation and for applications such as in the solar energy or agriculture sector. The Satellite Application Facility on Climate Monitoring (CM SAF) released a Climate Data Record (CDR) of global and direct surface irradiance as well as effective cloud albedo derived from observations of the Meteosat First Generation satellites (MFG, 1983-2005). We will present an extension of this CDR using measurements from the Meteosat Second Generation satellites (MSG, 2004-present). The differences in the spectral properties of the radiometers aboard the MFG and MSG satellites requires a modification of the original MagicSol algorithm. In order to guarantee a climatologically homogeneous continuation of MFG-based CDR, the two narrowband visible channels of the MSG satellites are combined to simulate the MFG broadband visible channel. The combination of the MFG and MSG based datasets is tested for homogeneity and no significant breaks are detected during the overlap period of 2004-2005. Validation of the extended global radiation dataset against ground based observations from the Baseline Surface Radiation Network yields a mean monthly absolute bias of 8.15 Wm-2. This complies to the target accuracy threshold of 15 Wm-2 (including a measurement uncertainty of the surface observations of 5 Wm-2) required for satellite-derived CDR's of global radiation by the Global Climate Observing System. Climatological analysis of the extended surface radiation dataset shows an overall positive trend of the global radiation for the Meteosat disc (with variable extents and significances for different regions) which can be attributed to a negative trend in the effective cloud albedo, i.e., a decrease in cloudiness. Trends due to changes in the clear sky radiation are small and only induced by trends in the water vapour fields. Trends caused by changes in the direct effects of

  16. Hanford Site climatological data summary 1999 with historical data

    International Nuclear Information System (INIS)

    This document presents the climatological data measured at the US Department of Energy's Hanford Site for calendar year 1999. Pacific Northwest National Laboratory operates the Hanford Meteorology Station and the Hanford Meteorological Monitoring Network from which these data were collected. The information contained herein includes updated historical climatologies for temperature, precipitation, normal and extreme values of temperature and precipitation, and other miscellaneous meteorological parameters. Further, the data are adjunct to and update Hoitink et al. (1999), and Hoitink and Burk (1994, 1995, 1996, 1997, 1998); however, Appendix B-Wind Climatology (1994) is excluded. 1999 was warmer than normal at the Hanford Meteorology Station with an average temperature of 54.4 F, 1.1 F above normal (53.3 F). The hottest temperature was 105 F on July 28, while the coldest was 18 F on January 3. The maximum temperature of 64 F on August 30 was the lowest maximum temperature ever recorded in August, while the maximum temperature of 76 F on November 13 was the highest maximum temperature ever recorded in November. For the 12-month period, 6 months were warmer than normal and 6 were cooler than normal. 1999 was the fourth driest year on record. Precipitation totaled 3.75 inches, 60% of normal (6.26 inches); snowfall totaled 0.6 inch, the least calendar year snowfall on record (compared to the normal of 13.8 inches). 1999 was the windiest year on record with an average wind speed of 8.8 mph, 1.1 mph above normal (7.7 mph). There were 48 days with peak gust ge 40 mph, compared to a yearly average of 26 mph. The peak gust during the year was 65 mph on February 6. The heating-degree days for 1998--1999 were 4,802 (8% below the 5,231 normal). Cooling-degree days for 1999 were 891 (10% below the 994 normal)

  17. LARGE SCALE WIND CLIMATOLOGICAL EXAMINATIONS OF WIND ENERGY UTILIZATION

    Directory of Open Access Journals (Sweden)

    ANDREA KIRCSI

    2008-12-01

    Full Text Available The aim of this article is to describe the particular field of climatology which analyzes air movement characteristics regarding utilization of wind for energy generation. The article describes features of wind energy potential available in Hungary compared to wind conditions in other areas of the northern quarter sphere in order to assist the wind energy use development in Hungary. Information on wind climate gives a solid basis for financial and economic decisions of stakeholders in the field of wind energy utilization.

  18. ?Strange Attractors (chaos) in the hydro-climatology of Colombia?

    International Nuclear Information System (INIS)

    Inter annual hydro-climatology of Colombia is strongly influenced by extreme phases of ENSO, a phenomenon exhibiting many features of chaotic non-linear system. The possible chaotic nature of Colombian hydrology is examined by using time series of monthly precipitation at Bogota (1866-1992) and Medellin (1908-1995), and average stream flows of the Magdalena River at Puerto Berrio. The power spectrum, the Haussdorf-Besikovich (fractal) dimension, the correlation dimension, and the largest Lyapunov exponent are estimated for the time series. Ideas of hydrologic forecasting and predictability are discussed in the context of nonlinear dynamical systems exhibit chaotic behavior

  19. Mars Geoscience Climatology Orbiter (MGCO) extended study: Technical volume

    Science.gov (United States)

    1983-01-01

    The FLTSATCOM Earth orbiting communications satellite is a prominent candidate to serve as the Mars Geoscience Climatology Orbiter (MGCO) spacecraft. Major aspects directly applicable are: (1) the incorporation of solid orbit insertion motor; (2) the ability to cruise to Mars in the spin-stabilized mode; (3) ample capability for payload mass and power; (4) attitude control tried to nadir and orbit plane coordinates; (5) exemplary Earth orbital performance record and projected lifetime; and (6) existence of an on-going procurement into the MGCO time period.

  20. Statistical examination of climatological data relevant to global temperature variation

    Energy Technology Data Exchange (ETDEWEB)

    Gray, H.L.; Gunst, R.F.; Woodward, W.A.

    1992-01-01

    The research group at Southern Methodist University has been involved in the examination of climatological data as specified in the proposal. Our efforts have resulted in three papers which have been submitted to scholarly journals, as well as several other projects which should be completed either during the next six months or next year. In the following, we discuss our results to date along with projected progress within the next six months. Major topics discussed in this progress report include: testing for trend in the global temperature data; (2) defining and estimating mean global temperature change; and, (3) the effect of initial conditions on autoregressive models for global temperature data.

  1. Climatology of early night equatorial spread F over Jicamarca

    OpenAIRE

    Chapagain, N. P.; Fejer, Bela G.

    2009-01-01

    [1] We use radar observations from 1996 to 2006 to study the climatology of postsunset equatorial 3-m spread F irregularities over Jicamarca during all seasons. We show that the spread F onset times do not change with solar flux and that their onset heights, which occur near the altitude of the evening F region velocity vortex, increase linearly from about 260 to 400 km from solar minimum to solar maximum. Higher onset heights generally lead to stronger radar echoes. During the equinox, sprea...

  2. CLIMATOLOGICAL DIAGNOSIS OF WINTER TEMPERATURE VARIATIONS IN GUANGDONG

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Using the monthly mean and minimum temperature data of the 36 observation stations in Guangdong, the climatological features of the temperatures have been analyzed, including characteristics of trends, abrupt changes and periods. And the possible affecting factors on the winter warming in Guangdong have been discussed. The results show that the winter temperatures, particularly the monthly mean minimum temperatures in Guangdong, have a warming trend. The rise of the winter minimum temperatures in Guangdong began in the second half of 1960's and the warming was more evident since the 1980's.

  3. Climatology in support of climate risk management : a progress report.

    OpenAIRE

    McGregor, G. R.

    2015-01-01

    Climate risk management has emerged over the last decade as a distinct area of activity within the wider field of climatology. Its focus is on integrating climate and non-climate information in order to enhance the decision-making process in a wide range of climate-sensitive sectors of society, the economy and the environment. Given the burgeoning pure and applied climate science literature that addresses a range of climate risks, the purpose of this progress report is to provide an overview ...

  4. Characteristics of cyclone climatology and variability in the Southern Ocean

    Institute of Scientific and Technical Information of China (English)

    WEI Lixin; QIN Ting

    2016-01-01

    A new climatology of cyclones in the Southern Ocean is generated by applying an automated cyclone detection and tracking algorithm (developed by Hodges at the Reading University) for an improved and relatively high-resolution European Centre for Medium-Range Weather Forecasts atmospheric reanalysis during 1979–2013. A validation shows that identified cyclone tracks are in good agreement with a available analyzed cyclone product. The climatological characteristics of the Southern Ocean cyclones are then analyzed, including track, number, density, intensity, deepening rate and explosive events. An analysis shows that the number of cyclones in the Southern Ocean has increased for 1979–2013, but only statistically significant in summer. Coincident with the circumpolar trough, a single high-density band of cyclones is observed in 55°–67°S, and cyclone density has generally increased in north of this band for 1979–2013, except summer. The intensity of up to 70% cyclones in the Southern Ocean is less than 980 hPa, and only a few cyclones with pressure less than 920 hPa are detected for 1979–2013. Further analysis shows that a high frequency of explosive cyclones is located in the band of 45°–55°S, and the Atlantic Ocean sector has much higher frequent occurrence of the explosive cyclones than that in the Pacific Ocean sector. Additionally, the relationship between cyclone activities in the Southern Ocean and the Southern Annular Mode is discussed.

  5. A New Global Climatology of Annual Land Surface Temperature

    Directory of Open Access Journals (Sweden)

    Benjamin Bechtel

    2015-03-01

    Full Text Available Land surface temperature (LST is an important parameter in various fields including hydrology, climatology, and geophysics. Its derivation by thermal infrared remote sensing has long tradition but despite substantial progress there remain limited data availability and challenges like emissivity estimation, atmospheric correction, and cloud contamination. The annual temperature cycle (ATC is a promising approach to ease some of them. The basic idea to fit a model to the ATC and derive annual cycle parameters (ACP has been proposed before but so far not been tested on larger scale. In this study, a new global climatology of annual LST based on daily 1 km MODIS/Terra observations was processed and evaluated. The derived global parameters were robust and free of missing data due to clouds. They allow estimating LST patterns under largely cloud-free conditions at different scales for every day of year and further deliver a measure for its accuracy respectively variability. The parameters generally showed low redundancy and mostly reflected real surface conditions. Important influencing factors included climate, land cover, vegetation phenology, anthropogenic effects, and geology which enable numerous potential applications. The datasets will be available at the CliSAP Integrated Climate Data Center pending additional processing.

  6. Recent Trends of the Tropical Hydrological Cycle Inferred from Global Precipitation Climatology Project and International Satellite Cloud Climatology Project data

    Science.gov (United States)

    Zhou, Y. P.; Xu, Kuan-Man; Sud, Y. C.; Betts, A. K.

    2011-01-01

    Scores of modeling studies have shown that increasing greenhouse gases in the atmosphere impact the global hydrologic cycle; however, disagreements on regional scales are large, and thus the simulated trends of such impacts, even for regions as large as the tropics, remain uncertain. The present investigation attempts to examine such trends in the observations using satellite data products comprising Global Precipitation Climatology Project precipitation and International Satellite Cloud Climatology Project cloud and radiation. Specifically, evolving trends of the tropical hydrological cycle over the last 20-30 years were identified and analyzed. The results show (1) intensification of tropical precipitation in the rising regions of the Walker and Hadley circulations and weakening over the sinking regions of the associated overturning circulation; (2) poleward shift of the subtropical dry zones (up to 2deg/decade in June-July-August (JJA) in the Northern Hemisphere and 0.3-0.7deg/decade in June-July-August and September-October-November in the Southern Hemisphere) consistent with an overall broadening of the Hadley circulation; and (3) significant poleward migration (0.9-1.7deg/decade) of cloud boundaries of Hadley cell and plausible narrowing of the high cloudiness in the Intertropical Convergence Zone region in some seasons. These results support findings of some of the previous studies that showed strengthening of the tropical hydrological cycle and expansion of the Hadley cell that are potentially related to the recent global warming trends.

  7. Annual Climatology of the Diurnal Cycle on the Canadian Prairies

    Directory of Open Access Journals (Sweden)

    Alan K Betts

    2016-01-01

    Full Text Available We show the annual climatology of the diurnal cycle, stratified by opaque cloud, using the full hourly resolution of the Canadian Prairie data. The opaque cloud field itself has distinct cold and warm season diurnal climatologies; with a near-sunrise peak of cloud in the cold season and an early afternoon peak in the warm season. There are two primary climate states on the Canadian Prairies, separated by the freezing point of water, because a reflective surface snow cover acts as a climate switch. Both cold and warm season climatologies can be seen in the transition months of November, March and April with a large difference in mean temperature. In the cold season with snow, the diurnal ranges of temperature and relative humidity increase quasi-linearly with decreasing cloud, and increase from December to March with increased solar forcing. The warm season months, April to September, show a homogeneous coupling to the cloud cover, and a diurnal cycle of temperature and humidity that depends only on net longwave. Our improved representation of the diurnal cycle shows that the warm season coupling between diurnal temperature range and net longwave is weakly quadratic through the origin, rather than the linear coupling shown in earlier papers. We calculate the conceptually important 24-h imbalances of temperature and relative humidity (and other thermodynamic variables as a function of opaque cloud cover. In the warm season under nearly clear skies, there is a warming of +2oC and a drying of -6% over the 24-h cycle, which is about 12% of their diurnal ranges. We summarize results on conserved variable diagrams and explore the impact of surface windspeed on the diurnal cycle in the cold and warm seasons. In all months, the fall in minimum temperature is reduced with increasing windspeed, which reduces the diurnal temperature range. In July and August, there is an increase of afternoon maximum temperature and humidity at low windspeeds, and a

  8. Eight-year Climatology of Dust Optical Depth on Mars

    CERN Document Server

    Montabone, L; Millour, E; Wilson, R J; Lewis, S R; Cantor, B A; Kass, D; Kleinboehl, A; Lemmon, M; Smith, M D; Wolff, M J

    2014-01-01

    We have produced a multiannual climatology of airborne dust from Martian year 24 to 31 using multiple datasets of retrieved or estimated column optical depths. The datasets are based on observations of the Martian atmosphere from April 1999 to July 2013 made by different orbiting instruments: the Thermal Emission Spectrometer (TES) aboard Mars Global Surveyor, the Thermal Emission Imaging System (THEMIS) aboard Mars Odyssey, and the Mars Climate Sounder (MCS) aboard Mars Reconnaissance Orbiter (MRO). The procedure we have adopted consists of gridding the available retrievals of column dust optical depth (CDOD) from TES and THEMIS nadir observations, as well as the estimates of this quantity from MCS limb observations. Our gridding method calculates averages and uncertainties on a regularly spaced, but possibly incomplete, spatio-temporal grid, using an iterative procedure weighted in space, time, and retrieval uncertainty. In order to evaluate strengths and weaknesses of the resulting gridded maps, we validat...

  9. Evaluation of global climate models for Indian monsoon climatology

    International Nuclear Information System (INIS)

    The viability of global climate models for forecasting the Indian monsoon is explored. Evaluation and intercomparison of model skills are employed to assess the reliability of individual models and to guide model selection strategies. Two dominant and unique patterns of Indian monsoon climatology are trends in maximum temperature and periodicity in total rainfall observed after 30 yr averaging over India. An examination of seven models and their ensembles reveals that no single model or model selection strategy outperforms the rest. The single-best model for the periodicity of Indian monsoon rainfall is the only model that captures a low-frequency natural climate oscillator thought to dictate the periodicity. The trend in maximum temperature, which most models are thought to handle relatively better, is best captured through a multimodel average compared to individual models. The results suggest a need to carefully evaluate individual models and model combinations, in addition to physical drivers where possible, for regional projections from global climate models. (letter)

  10. The Mars Geoscience/Climatology Orbiter 1990 mission

    Science.gov (United States)

    Low, G. D.; Stuart, J. R.; Palluconi, F. D.; Blume, W. H.; Erickson, K. D.

    1984-01-01

    The fundamental objectives of the Mars Geoscience/Climatology Orbiter (MGCO) 1990 mission are related to the determination of the surface composition and topography of the planet Mars, its gravitational and intrinsic magnetic fields, and the seasonal behavior of volatiles, dust, and the atmosphere of Mars. These objectives would be achieved through a global mapping of the planet over a Martian year. For the baseline mission, a single spacecraft would be launched in August 1990, arrive at Mars in August 1991, and map the planet from a Sun-synchronous, near-circular, polar orbit for one Martian year. Attention is given to a science rationale and objectives, a mission description, the flight system, and mission operations.

  11. Deuterium excess in precipitation and its climatological significance

    International Nuclear Information System (INIS)

    The climatological significance of the deuterium excess parameter for tracing precipitation processes is discussed with reference to data collected within the IAEA/WMO Global Network for Isotopes in Precipitation (GNIP) programme. Annual and monthly variations in deuterium excess, and their primary relationships with δ18O, temperature, vapour pressure and relative humidity are used to demonstrate fundamental controls on deuterium excess for selected climate stations and transects. The importance of deuterium excess signals arising from ocean sources versus signals arising from air mass modification during transport over the continents is reviewed and relevant theoretical development is presented. While deuterium excess shows considerable promise as a quantitative index of precipitation processes, the effectiveness of current applications using GNIP is largely dependent on analytical uncertainty (∼2.1 per mille), which could be improved to better than 1 per mille through basic upgrades in routine measurement procedures for deuterium analysis. (author)

  12. High resolution climatological wind measurements for wind energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, H. [Uppsala Univ. (Sweden). Dept. of Meteorology

    1996-12-01

    Measurements with a combined cup anemometer/wind vane instrument, developed at the Department of Meteorology in Uppsala, is presented. The instrument has a frequency response of about 1 Hz, making it suitable not only for mean wind measurements, but also for studies of atmospheric turbulence. It is robust enough to be used for climatological purposes. Comparisons with data from a hot-film anemometer show good agreement, both as regards standard deviations and the spectral decomposition of the turbulent wind signal. The cup anemometer/wind vane instrument is currently used at three sites within the Swedish wind energy research programme. These measurements are shortly described, and a few examples of the results are given. 1 ref, 10 figs

  13. The Global Precipitation Climatology Centre (GPCC) - in situ observation based precipitation climatology on regional and global scale

    Science.gov (United States)

    Fuchs, T.; Schneider, U.; Rudolf, B.

    2009-04-01

    The Global Precipitation Climatology Centre (GPCC, http://gpcc.dwd.de) provides global monthly precipitation analyses for monitoring and research of the earth's climate. The centre is a German contribution to the World Climate Research Programme (WCRP), to the Global Climate Observing System (GCOS), and to the Global Earth Observation System of Systems (GEOSS). It contributes to water resources assessments, flood and drought monitoring, climate variability and trend analyses. GPCC published in year 2008 a new global precipitation climatology as well as a reanalysis of its full data base for all months of the period 1901-2007. The GPCC data base comprises monthly precipitation totals from more than 70 000 different stations in the world. It produces gridded data sets of monthly precipitation on the earth's land surface derived from raingauge based observation data. Intensive quality control of observation data and station metadata ensures a high analysis quality. The different GPCC products are adjusted to different user needs. It routinely produces 2 near real-time precipitation monitoring products. Its 2 non real-time products are updated at irregular time intervals after significant updates of its observation station database. All GPCC products can be visualised and accessed free of charge via Internet from http://gpcc.dwd.de. The GPCC First Guess Product of the monthly precipitation anomaly is based on synoptic weather reports (SYNOP) from about 6,300 stations worldwide received near real-time via the WMO Global Telecommunication System (GTS). The product is available within 5 days after end of an observation month. Main application purpose is near real-time drought monitoring. The product uses since mid 2008 the new GPCC monthly precipitation climatology as analysis background. Spatial product resolution: 1.0° and 2.5°. The GPCC Monitoring Product of monthly precipitation is based on SYNOP and monthly CLIMAT reports received near real-time via GTS from about

  14. Quantifying climatological ranges and anomalies for Pacific coral reef ecosystems.

    Directory of Open Access Journals (Sweden)

    Jamison M Gove

    Full Text Available Coral reef ecosystems are exposed to a range of environmental forcings that vary on daily to decadal time scales and across spatial scales spanning from reefs to archipelagos. Environmental variability is a major determinant of reef ecosystem structure and function, including coral reef extent and growth rates, and the abundance, diversity, and morphology of reef organisms. Proper characterization of environmental forcings on coral reef ecosystems is critical if we are to understand the dynamics and implications of abiotic-biotic interactions on reef ecosystems. This study combines high-resolution bathymetric information with remotely sensed sea surface temperature, chlorophyll-a and irradiance data, and modeled wave data to quantify environmental forcings on coral reefs. We present a methodological approach to develop spatially constrained, island- and atoll-scale metrics that quantify climatological range limits and anomalous environmental forcings across U.S. Pacific coral reef ecosystems. Our results indicate considerable spatial heterogeneity in climatological ranges and anomalies across 41 islands and atolls, with emergent spatial patterns specific to each environmental forcing. For example, wave energy was greatest at northern latitudes and generally decreased with latitude. In contrast, chlorophyll-a was greatest at reef ecosystems proximate to the equator and northern-most locations, showing little synchrony with latitude. In addition, we find that the reef ecosystems with the highest chlorophyll-a concentrations; Jarvis, Howland, Baker, Palmyra and Kingman are each uninhabited and are characterized by high hard coral cover and large numbers of predatory fishes. Finally, we find that scaling environmental data to the spatial footprint of individual islands and atolls is more likely to capture local environmental forcings, as chlorophyll-a concentrations decreased at relatively short distances (>7 km from 85% of our study locations

  15. Revisiting the Climatology of Atmospheric Blocking in the Northern Hemisphere

    Institute of Scientific and Technical Information of China (English)

    Ho Nam CHEUNG; ZHOU Wen; Hing Yim MOK; Man Chi WU; Yaping SHAO

    2013-01-01

    In addition to the occurrence of atmospheric blocking,the climatology of the characteristics of blocking events,including duration,intensity,and extension,in four seasons over the Northern Hemisphere was analyzed for the period 1950-2009.The seasonality and spatial variations of these characteristics were studied according to their longitudinal distributions.In general,there were sharp discrepancies in the blocking characteristics between winter and summer,and these differences were more prominent over the Atlantic and Pacific Oceans.The blocking not only occurred more frequently but also underwent stronger amplification in winter; likewise,the blocking occurred less frequently and underwent weaker amplification in summer.There are very strong interrelationships among different blocking characteristics,suggesting that they are supported by similar physical factors.In addition,the relationship between blocking over different regions and East Asian circulation was examined.Ural-Siberia is a major blocking formation region in all seasons that may exert a downstream impact on East Asia.The impact is generally weak in summer,which is due to its lower intensity and smaller duration.However,the extratropical circulation over East Asia in summer can be disturbed persistently by the frequent occurrence of blocking over the Asian continent or the Western Pacific.In particular,the blocking frequency over the Western Pacific significantly increased during the study period.This climatological information provides a background for studying the impact of blocking on East Asian circulation under both present and future climate conditions.

  16. Quantifying climatological ranges and anomalies for Pacific coral reef ecosystems.

    Science.gov (United States)

    Gove, Jamison M; Williams, Gareth J; McManus, Margaret A; Heron, Scott F; Sandin, Stuart A; Vetter, Oliver J; Foley, David G

    2013-01-01

    Coral reef ecosystems are exposed to a range of environmental forcings that vary on daily to decadal time scales and across spatial scales spanning from reefs to archipelagos. Environmental variability is a major determinant of reef ecosystem structure and function, including coral reef extent and growth rates, and the abundance, diversity, and morphology of reef organisms. Proper characterization of environmental forcings on coral reef ecosystems is critical if we are to understand the dynamics and implications of abiotic-biotic interactions on reef ecosystems. This study combines high-resolution bathymetric information with remotely sensed sea surface temperature, chlorophyll-a and irradiance data, and modeled wave data to quantify environmental forcings on coral reefs. We present a methodological approach to develop spatially constrained, island- and atoll-scale metrics that quantify climatological range limits and anomalous environmental forcings across U.S. Pacific coral reef ecosystems. Our results indicate considerable spatial heterogeneity in climatological ranges and anomalies across 41 islands and atolls, with emergent spatial patterns specific to each environmental forcing. For example, wave energy was greatest at northern latitudes and generally decreased with latitude. In contrast, chlorophyll-a was greatest at reef ecosystems proximate to the equator and northern-most locations, showing little synchrony with latitude. In addition, we find that the reef ecosystems with the highest chlorophyll-a concentrations; Jarvis, Howland, Baker, Palmyra and Kingman are each uninhabited and are characterized by high hard coral cover and large numbers of predatory fishes. Finally, we find that scaling environmental data to the spatial footprint of individual islands and atolls is more likely to capture local environmental forcings, as chlorophyll-a concentrations decreased at relatively short distances (>7 km) from 85% of our study locations. These metrics will help

  17. Climatological/meteorological and hydrological disasters and the insurance sector

    Directory of Open Access Journals (Sweden)

    Murat Türkeş

    2010-11-01

    Full Text Available Climate change is a continual fact during the Earth’s history. There had been many significant changes in the Earth’s climate during its evolutionary history and a lot of ecosystems had been affected by these changes. Especially the industrialization process showing rapid movement after industrial revolution has put serious pressure on the present and future climate. Human activities such as increased fossil fuel usage with the industrialization process, land-use changes, industrial processes and deforestation have increased atmospheric accumulation up of the various greenhouse gases such as carbon dioxide (CO2, methane (CH4, nitrous oxide (N2O. On the other hand, increase in frequency and severity of natural disasters can be explained mostly by the increase of the probability of extreme events due to the climate change. Increased numbers of people have been affected by climatological and meteorological catastrophes in every year. Various actions and activities such as disaster preparedness, mitigation, reduction and prevention of the impacts and early warnings are considerable with respect to the insurance sector. These activities and actions should be implemented in the frame of contemporary and comprehensive disaster management planes. Scope of the natural disaster should be expanded particularly in the countries and regions that are vulnerable to the impacts of the climate change and variability including drought events and/or natural disasters. Moreover, drought events should also be accepted as one of the severe natural disasters, and sustainable and applicable drought management plans should be developed in order to mitigate these disasters. In this context, main purpose of the study is to classify and shortly assess the climatological and meteorological disasters, and to attract attention necessity of a new disaster insurance system containing these disasters.

  18. The climatology of dust aerosol over the arabian peninsula

    Directory of Open Access Journals (Sweden)

    A. Shalaby

    2015-01-01

    Full Text Available Dust storms are considered to be a natural hazard over the Arabian Peninsula, since they occur all year round with maximum intensity and frequency in Spring and Summer. The Regional Climate Model version 4 (RegCM4 has been used to study the climatology of atmospheric dust over the Arabian Peninsula from 1999 to 2012. This relatively long simulation period samples the meteorological conditions that determine the climatology of mineral dust aerosols over the Arabian Peninsula. The modeled Aerosol Optical Depth (AOD has been compared against ground-based observations of three Aerosol Robotic Network (AERONET stations that are distributed over the Arabian Peninsula and daily space based observations from the Multi-angle Imaging SpectroRadiometer (MISR, the Moderate resolution Imaging SpectroRadimeter (MODIS and Ozone Monitoring Instrument (OMI. The large scale atmospheric circulation and the land surface response that lead to dust uplifting have been analyzed. While the modeled AOD shows that the dust season extends from March to August with two pronounced maxima, one over the northern Arabian Peninsula in March with AOD equal to 0.4 and one over the southern Arabian Peninsula in July with AOD equal to 0.7, the observations show that the dust season extends from April to August with two pronounced maxima, one over the northern Arabian Peninsula in April with AOD equal to 0.5 and one over the southern Arabian Peninsula in July with AOD equal to 0.5. In spring a high pressure dominates the Arabian Peninsula and is responsible for advecting dust from southern and western part of the Arabian Peninsula to northern and eastern part of the Peninsula. Also, fast developed cyclones in northern Arabian Peninsula are responsible for producing strong dust storms over Iraq and Kuwait. However, in summer the main driver of the surface dust emission is the strong northerly wind ("Shamal" that transport dust from the northern Arabian Peninsula toward south parallel

  19. Modeling the effect of climatological drought on European wildfire extent

    Science.gov (United States)

    Stagge, James H.; Dias, Susana; Rego, Francisco; Tallaksen, Lena M.

    2014-05-01

    Wildfires are a natural hazard most commonly associated with the Mediterranean region in Europe, but which can affect all regions and cause significant impact and damage. Because vegetation dryness is a primary factor in both the ignition and spread of wildfires, it is assumed that there is a link between climatological drought and wildfire extent in Europe. The objective of this study is therefore to test this link between wildfire extent, defined by area burned, and several climatological drought indices across all geoclimatic regions of Europe, eventually determining the relative effect and most relevant combination of these indices on fire extent. Using the European Fire Database, compiled by the EU Joint Research Centre, these analyses are performed at the national and sub-national (NUTS 1,2,3) scale for 22 countries. Drought indices used as predictor variables include the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI), which calculate anomalies in precipitation and climatic water balance, respectively, accumulated over several periods (1, 2, 3, 6, 9, 12, and 24 months). Climate data is based on the gridded Watch Forcing Dataset ERA-Interim (WFDEI), which spans the duration of the wildfire series (1985-2010). Two methods of analysis are used in this study. First, the annual maximum wildfire extent for each country or region is modeled using multiple linear regression for all possible linear combinations of the drought indices. Second, wildfire extent is modeled individually for each month to determine how the relevant drought indices change throughout the wildfire season. Preliminary results show that, for the majority of European countries, wildfire extent is most strongly related to short-term (2-3 month) SPEI anomalies, which represent a combined lack of precipitation and increased evapotranspiration associated with high temperatures. Longer accumulated dryness (6-9 months) was also related to

  20. Climatology of damage-causing hailstorms over Germany

    Science.gov (United States)

    Kunz, M.; Puskeiler, M.; Schmidberger, M.

    2012-04-01

    In several regions of Central Europe, such as southern Germany, Austria, Switzerland, and northern Italy, hailstorms often cause substantial damage to buildings, crops, or automobiles on the order of several million EUR. In the federal state of Baden-Württemberg, for example, most of the insured damage to buildings is caused by large hailstones. Due to both their local-scale extent and insufficient direct monitoring systems, hail swaths are not captured accurately and uniquely by a single observation system. Remote-sensing systems such as radars are able to detect convection signals in a basic way, but they lack the ability to discern a clear relation between measured intensity and hail on the ground. These shortcomings hamper statistical analysis on the hail probability and intensity. Hail modelling thus is a big challenge for the insurance industry. Within the project HARIS-CC (Hail Risk and Climate Change), different meteorological observations are combined (3D / 2D radar, lightning, satellite and radiosounding data) to obtain a comprehensive picture of the hail climatology over Germany. The various approaches were tested and calibrated with loss data from different insurance companies between 2005 and 2011. Best results are obtained by considering the vertical distance between the 0°C level of the atmosphere and the echo top height estimated from 3D reflectivity data from the radar network of German Weather Service (DWD). Additionally, frequency, intensity, width, and length of hail swaths are determined by applying a cell tracking algorithm to the 3D radar data (TRACE3D; Handwerker, 2002). The hailstorm tracks identified are merged with loss data using a geographical information system (GIS) to verify damage-causing hail on the ground. Evaluating the hailstorm climatology revealed that hail probability exhibits high spatial variability even over short distances. An important issue is the spatial pattern of hail occurrence that is considered to be due to

  1. Available climatological and oceanographical data for site investigation program

    Energy Technology Data Exchange (ETDEWEB)

    Lindell, S.; Ambjoern, C.; Juhlin, B.; Larsson-McCann, S.; Lindquist, K. [Swedish Meteorological and Hydrological Inst., Norrkoeping (Sweden)

    2000-03-15

    Information on available data, measurements and models for climate, meteorology, hydrology and oceanography for six communities have been analysed and studied. The six communities are Nykoeping, Oesthammar, Oskarshamn, Tierp, Hultsfred and Aelvkarleby all of them selected by Svensk Kaernbraenslehantering AB, SKB, for a pre-study on possibilities for deep disposal of used nuclear fuel. For each of them a thorough and detailed register of available climatological data together with appropriate statistical properties are listed. The purpose is to compare the six communities concerning climatological and oceanographical data available and analyse the extent of new measurements or model applications needed for all of the selected sites. Statistical information on precipitation, temperature and runoff has good coverage in all of the six communities. If new information concerning any of these variables is needed in sites where no data collection exist today new installation can be made. Data on precipitation in form of snow and days with snow coverage is also available but to a lesser extent. This concerns also days with ground frost and average ground frost level where there is no fully representation of data. If more information is wanted concerning these variables new measurements or model calculations must be initiated. Data on freeze and break-up of ice on lakes is also insufficient but this variable can be calculated with good result by use of one-dimensional models. Data describing air pressure tendency and wind velocity and direction is available for all communities and this information should be sufficient for the purpose of SKB. This is also valid for the variables global radiation and duration of sunshine where no new data should be needed. Measured data on evaporation is normally not available in Sweden more than in special research basins. Actual evaporation is though a variable that easily can be calculated by use of models. There are many lakes in the six

  2. A Precipitation Climatology of the Snowy Mountains, Australia

    Science.gov (United States)

    Theobald, Alison; McGowan, Hamish; Speirs, Johanna

    2014-05-01

    The precipitation that falls in the Snowy Mountains region of southeastern Australia provides critical water resources for hydroelectric power generation. Water storages in this region are also a major source of agricultural irrigation, environmental flows, and offer a degree of flood protection for some of the major river systems in Australia. Despite this importance, there remains a knowledge gap regarding the long-term, historic variability of the synoptic weather systems that deliver precipitation to the region. This research aims to increase the understanding of long-term variations in precipitation-bearing weather systems resulting in runoff into the Snowy Mountains catchments and reservoirs, and the way in which these are influenced by large-scale climate drivers. Here we present initial results on the development of a climatology of precipitation-bearing synoptic weather systems (synoptic typology), spanning a period of over 100 years. The synoptic typology is developed from the numerical weather model re-analysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF), in conjunction with regional precipitation and temperature data from a network of private gauges. Given the importance of surface, mid- and upper-air patterns on seasonal precipitation, the synoptic typing will be based on a range of meteorological variables throughout the depth of the troposphere, highlighting the importance of different atmospheric levels on the development and steering of synoptic precipitation bearing systems. The temporal and spatial variability of these synoptic systems, their response to teleconnection forcings and their contribution to inflow generation in the headwater catchments of the Snowy Mountains will be investigated. The resulting climatology will provide new understanding of the drivers of regional-scale precipitation variability at inter- and intra-annual timescales. It will enable greater understanding of how variability in synoptic scale

  3. Situational Lightning Climatologies for Central Florida: Phase V

    Science.gov (United States)

    Bauman, William H., III

    2011-01-01

    The AMU added three years of data to the POR from the previous work resulting in a 22-year POR for the warm season months from 1989-2010. In addition to the flow regime stratification, moisture and stability stratifications were added to separate more active from less active lighting days within the same flow regime. The parameters used for moisture and stability stratifications were PWAT and TI which were derived from sounding data at four Florida radiosonde sites. Lightning data consisted of NLDN CG lightning flashes within 30 NM of each airfield. The AMU increased the number of airfields from nine to thirty-six which included the SLF, CCAFS, PAFB and thirty-three airfields across Florida. The NWS MLB requested the AMU calculate lightning climatologies for additional airfields that they support as a backup to NWS TBW which was then expanded to include airfields supported by NWS JAX and NWS MFL. The updated climatologies of lightning probabilities are based on revised synoptic-scale flow regimes over the Florida peninsula (Lambert 2007) for 5-, 10-, 20- and 30-NM radius range rings around the thirty-six airfields in 1-, 3- and 6-hour increments. The lightning, flow regime, moisture and stability data were processed in S-PLUS software using scripts written by the AMU to automate much of the data processing. The S-PLUS data files were exported to Excel to allow the files to be combined in Excel Workbooks for easier data handling and to create the tables and charts for the Gill. The AMU revised the Gill developed in the previous phase (Bauman 2009) with the new data and provided users with an updated HTML tool to display and manipulate the data and corresponding charts. The tool can be used with most web browsers and is computer operating system independent. The AMU delivered two Gills - one with just the PWAT stratification and one with both the PWAT and TI stratifications due to insufficient data in some of the PWATITI stratification combinations. This will allow

  4. Climatological context for large-scale coral bleaching

    Science.gov (United States)

    Barton, A. D.; Casey, K. S.

    2005-12-01

    Large-scale coral bleaching was first observed in 1979 and has occurred throughout virtually all of the tropics since that time. Severe bleaching may result in the loss of live coral and in a decline of the integrity of the impacted coral reef ecosystem. Despite the extensive scientific research and increased public awareness of coral bleaching, uncertainties remain about the past and future of large-scale coral bleaching. In order to reduce these uncertainties and place large-scale coral bleaching in the longer-term climatological context, specific criteria and methods for using historical sea surface temperature (SST) data to examine coral bleaching-related thermal conditions are proposed by analyzing three, 132 year SST reconstructions: ERSST, HadISST1, and GISST2.3b. These methodologies are applied to case studies at Discovery Bay, Jamaica (77.27°W, 18.45°N), Sombrero Reef, Florida, USA (81.11°W, 24.63°N), Academy Bay, Galápagos, Ecuador (90.31°W, 0.74°S), Pearl and Hermes Reef, Northwest Hawaiian Islands, USA (175.83°W, 27.83°N), Midway Island, Northwest Hawaiian Islands, USA (177.37°W, 28.25°N), Davies Reef, Australia (147.68°E, 18.83°S), and North Male Atoll, Maldives (73.35°E, 4.70°N). The results of this study show that (1) The historical SST data provide a useful long-term record of thermal conditions in reef ecosystems, giving important insight into the thermal history of coral reefs and (2) While coral bleaching and anomalously warm SSTs have occurred over much of the world in recent decades, case studies in the Caribbean, Northwest Hawaiian Islands, and parts of other regions such as the Great Barrier Reef exhibited SST conditions and cumulative thermal stress prior to 1979 that were comparable to those conditions observed during the strong, frequent coral bleaching events since 1979. This climatological context and knowledge of past environmental conditions in reef ecosystems may foster a better understanding of how coral reefs will

  5. Available climatological and oceanographical data for site investigation program

    International Nuclear Information System (INIS)

    Information on available data, measurements and models for climate, meteorology, hydrology and oceanography for six communities have been analysed and studied. The six communities are Nykoeping, Oesthammar, Oskarshamn, Tierp, Hultsfred and Aelvkarleby all of them selected by Svensk Kaernbraenslehantering AB, SKB, for a pre-study on possibilities for deep disposal of used nuclear fuel. For each of them a thorough and detailed register of available climatological data together with appropriate statistical properties are listed. The purpose is to compare the six communities concerning climatological and oceanographical data available and analyse the extent of new measurements or model applications needed for all of the selected sites. Statistical information on precipitation, temperature and runoff has good coverage in all of the six communities. If new information concerning any of these variables is needed in sites where no data collection exist today new installation can be made. Data on precipitation in form of snow and days with snow coverage is also available but to a lesser extent. This concerns also days with ground frost and average ground frost level where there is no fully representation of data. If more information is wanted concerning these variables new measurements or model calculations must be initiated. Data on freeze and break-up of ice on lakes is also insufficient but this variable can be calculated with good result by use of one-dimensional models. Data describing air pressure tendency and wind velocity and direction is available for all communities and this information should be sufficient for the purpose of SKB. This is also valid for the variables global radiation and duration of sunshine where no new data should be needed. Measured data on evaporation is normally not available in Sweden more than in special research basins. Actual evaporation is though a variable that easily can be calculated by use of models. There are many lakes in the six

  6. Climatology and Impact of Convection on the Tropical Tropopause Layer

    Science.gov (United States)

    Robertson, Franklin; Pittman, Jasna

    2007-01-01

    Water vapor plays an important role in controlling the radiative balance and the chemical composition of the Tropical Tropopause Layer (TTL). Mechanisms ranging from slow transport and dehydration under thermodynamic equilibrium conditions to fast transport in convection have been proposed as regulators of the amount of water vapor in this layer. However,.details of these mechanisms and their relative importance remain poorly understood, The recently completed Tropical Composition, Cloud, and Climate Coupling (TC4) campaign had the opportunity to sample the.TTL over the Eastern Tropical Pacific using ground-based, airborne, and spaceborne instruments. The main goal of this study is to provide the climatological context for this campaign of deep and overshooting convective activity using various satellite observations collected during the summertime. We use the Microwave Humidity Sensor (MRS) aboard the NOAA-18 satellite to investigate the horizontal extent.and the frequency of convection reaching and penetrating into the TTL. We use the Moderate Resolution I1l1aging Spectroradiometer (MODIS) aboard the Aqua satellite to investigate the frequency distribution of daytime cirrus clouds. We use the Tropical Rainfall Measuring Mission(TRMM) and CloudSat to investigate the vertical structure and distribution of hydrometeors in the convective cells, In addition to cloud measurements; we investigate the impact that convection has on the concentration of radiatively important gases such as water vapor and ozone in the TTL by examining satellite measurement obtained from the Microwave Limb Sounder(MLS) aboard the Aura satellite.

  7. Updated population metadata for United States historical climatology network stations

    Science.gov (United States)

    Owen, T.W.; Gallo, K.P.

    2000-01-01

    The United States Historical Climatology Network (HCN) serial temperature dataset is comprised of 1221 high-quality, long-term climate observing stations. The HCN dataset is available in several versions, one of which includes population-based temperature modifications to adjust urban temperatures for the "heat-island" effect. Unfortunately, the decennial population metadata file is not complete as missing values are present for 17.6% of the 12 210 population values associated with the 1221 individual stations during the 1900-90 interval. Retrospective grid-based populations. Within a fixed distance of an HCN station, were estimated through the use of a gridded population density dataset and historically available U.S. Census county data. The grid-based populations for the HCN stations provide values derived from a consistent methodology compared to the current HCN populations that can vary as definitions of the area associated with a city change over time. The use of grid-based populations may minimally be appropriate to augment populations for HCN climate stations that lack any population data, and are recommended when consistent and complete population data are required. The recommended urban temperature adjustments based on the HCN and grid-based methods of estimating station population can be significantly different for individual stations within the HCN dataset.

  8. TRMM's Contribution to Our Knowledge of Climatology, Storms and Floods

    Science.gov (United States)

    Adler, Robert

    2007-01-01

    The Tropical Rainfall Measuring Mission (TRMM) has successfully completed nearly ten years in orbit. A brief review of the history and accomplishments of this joint mission between the U.S. and Japan is presented. Research highlights will focus on the seasonal cycle of a TRMM-based rainfall climatology, which takes advantage of the multiple rain estimates available from TRMM. Examples will be given of the use of TRMM data to diagnose the impact of man on precipitation patterns through urbanization and the effect of pollution. Use of TRMM data for tropical cyclone operational analysis in the U.S. will also be shown. Methods for generating 3-hourly rainfall information from multiple satellites using TRMM to calibrate all the information will be described as will application of such information to study extreme rainfall events and associated floods and landslides. These results will emphasize the breadth of science success achieved with the 10-year record of observations from the only rain radar and passive microwave instrument combination in space. The outlook for continued operation of the TRMM satellite and progress in TRMM science and applications will be addressed.

  9. Steps Toward an EOS-Era Aerosol Type Climatology

    Science.gov (United States)

    Kahn, Ralph A.

    2012-01-01

    We still have a way to go to develop a global climatology of aerosol type from the EOS-era satellite data record that currently spans more than 12 years of observations. We have demonstrated the ability to retrieve aerosol type regionally, providing a classification based on the combined constraints on particle size, shape, and single-scattering albedo (SSA) from the MISR instrument. Under good but not necessarily ideal conditions, the MISR data can distinguish three-to-five size bins, two-to-four bins in SSA, and spherical vs. non-spherical particles. However, retrieval sensitivity varies enormously with scene conditions. So, for example, there is less information about aerosol type when the mid-visible aerosol optical depth (AOD) is less that about 0.15 or 0.2, or when the range of scattering angles observed is reduced by solar geometry, even though the quality of the AOD retrieval itself is much less sensitive to these factors. This presentation will review a series of studies aimed at assessing the capabilities, as well as the limitations, of MISR aerosol type retrievals involving wildfire smoke, desert dust, volcanic ash, and urban pollution, in specific cases where suborbital validation data are available. A synthesis of results, planned upgrades to the MISR Standard aerosol algorithm to improve aerosol type retrievals, and steps toward the development of an aerosol type quality flag for the Standard product, will also be covered.

  10. Climatology of air quality of Long Valley Geothermal Resource Area

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, K.R.; Palmer, T.Y.

    1977-06-01

    The Long Valley Known Geothermal Resource Area is one of the more promising regions for development of a large-scale geothermal energy center. This report discusses the climatology and air quality of the area. Details are given on the temperatures, temperature inversions, and winds. Estimates are presented for the present air quality and future air quality during and following development of the resource area. Also discussed are project impact from added pollutants, noise, and precipitation augmentation. The major deleterious effects from development of the Long Valley Geothermal Resource Area appear to be due to increased dust loading during and following construction, and noise from production testing and potential well blowouts. Increased pollution from release of hydrogen sulfide and other pollutants associated with hot water geothermal wells seems to present no problems with regard to surrounding vegetation, potential contamination of Lake Crowley, and odor problems in nearby communities. Precipitation augmentation will probably increase the water level of Lake Crowley, at the expense of possible additional fogging and icing of nearby highways.

  11. Agro-climatology of the Colombian Caribbean Region

    International Nuclear Information System (INIS)

    The agro-meteorology has for object the knowledge of the physical environment where the plants and the animals are developed, to make of him a better use, with the primordial purpose of optimizing the agricultural production. The climatology of the Caribbean Region, it is governed by the zonal processes of thermal and dynamic convection, together with the effect of the Inter-tropical Confluence Area (ITC) however, this extensive plain of the Colombian Caribbean, to be interrupted by the Sierra Nevada of Santa Marta and framed by the Caribbean Sea and the Andean mountain ranges, it makes that big differences are presented in their climatic regime. In this study, climatic elements are analyzed in the region, such as the precipitation, the temperature and the relative humidity of the air, the radiation and the solar shine, the speed of the wind and the potential evapo-perspiration, besides the calculation of the hydraulic balances, those which as integrative of the agriculture-climatic aspects, they serve as base to make the climatic classifications, to know the growth periods and to calculate the potential water demands, fundamental parameters in the planning of the agricultural activities. With these results they stand out the diverse climates in the region, represented in climatic areas from arid until per-humid offer a wide range for the requirements of the different species that are used in the agricultural exploitations

  12. Climatology of daily rainfall semivariance in The Netherlands

    Science.gov (United States)

    van de Beek, C. Z.; Leijnse, H.; Torfs, P. J. J. F.; Uijlenhoet, R.

    2010-03-01

    Rain gauges can offer high quality rainfall measurements at their location. Networks of rain gauges can offer better insight into the space-time variability of rainfall, but they tend to be too widely spaced for accurate estimates between points. While remote sensing systems, such as radars and networks of microwave links, can offer good insight in the spatial variability of rainfall they tend to have more problems in identifying the correct rain amounts at the ground. A way to estimate the variability of rainfall between gauge points is to interpolate between them using fitted variograms. If a dense rain gauge network is lacking it is difficult to estimate accurate variograms. In this paper a 30-year dataset of daily rain accumulations gathered at 29 automatic weather stations operated by KNMI and a one-year dataset of 10 gauges in a network with a radius of 5 km around CESAR (Cabauw Experimental Site for Atmospheric Research) are employed to estimate variograms. Fitted variogram parameters are shown to vary according to season, closely following simple cosine functions allowing for applications in catchment hydrology and rainfall field generation. Semivariances at short ranges during winter and spring tend to be underestimated, but summer and autumn are well predicted. This climatological semivariance can be employed to estimate the accuracy of the rainfall input to a hydrological model even with only few gauges in a given catchment area.

  13. Progress toward sustainable settlements: a role for urban climatology

    Science.gov (United States)

    Mills, G.

    2006-02-01

    Sustainable development can be defined as that which meets the needs of the current generation while leaving sufficient resources for the needs of future generations. A central objective is to decouple conventional resource use (and its corollary, waste generation) from economic development through technological innovation, improved efficiency and changes in individual practices. As the global population becomes urbanized and human activity is concentrated in urban areas, settlement planning is a key aspect of sustainability. The widespread inclusion of environmental objectives in urban plans at all scales provides an opportunity for the incorporation of urban climate knowledge into the planning process on a routine basis. Many of the stated objectives have both direct and indirect connections to climate. However, for this to happen, climate research and results must be linked more explicitly to the objectives of the sustainable settlement. In this paper, the relevance of sustainability to urban design and climate is discussed and the potential contribution of current urban climatology is assessed, identifying areas of special consideration for transfer to achieve sustainable urban planning and design.

  14. Generation of Fine Scale Wind and Wave Climatologies

    Science.gov (United States)

    Vandenberghe, F. C.; Filipot, J.; Mouche, A.

    2013-12-01

    A tool to generate 'on demand' large databases of atmospheric parameters at high resolution has been developed for defense applications. The approach takes advantage of the zooming and relocation capabilities of the embedded domains that can be found in regional models like the community Weather Research and Forecast model (WRF). The WRF model is applied to dynamically downscale NNRP, CFSR and ERA40 global analyses and to generate long records, up to 30 years, of hourly gridded data over 200km2 domains at 3km grid increment. To insure accuracy, observational data from the NCAR ADP historical database are used in combination with the Four-Dimensional Data Assimilation (FDDA) techniques to constantly nudge the model analysis toward observations. The atmospheric model is coupled to secondary applications such as the NOAA's Wave Watch III model the Navy's APM Electromagnetic Propagation model, allowing the creation of high-resolution climatologies of surface winds, waves and electromagnetic propagation parameters. The system was applied at several coastal locations of the Mediterranean Sea where SAR wind and wave observations were available during the entire year of 2008. Statistical comparisons between the model output and SAR observations are presented. Issues related to the global input data, and the model drift, as well as the impact of the wind biases on wave simulations will be discussed.

  15. DETERMINATION OF ATMOSPHERIC TURBIDITY AND ITS CORRELATION WITH CLIMATOLOGICALLY PARAMETERS

    Directory of Open Access Journals (Sweden)

    U. Ali Rahoma

    2012-01-01

    Full Text Available Study of Atmospheric turbidity is important for purposes of meteorology, ecology, climatology and monitoring of atmospheric pollution. Linke Turbidity factor (LT is commonly used to model the attenuation of solar radiation in the atmosphere. The probable dependence on the water vapor content of the relationship linking LT to Angstrom’s turbidity coefficient B, is discussed. In this study, a procedure for calculation of Linke turbidity factor is adopted using pyrheliometric measurements by Egyptian Typical Meteorological Year (ETMY at a Thirteen stations at Egypt, during (from 1969 to 2006. Monthly variations of the LT turbidity factor are found in the three studied months, with a maximum in August and a minimum in July. Detailed studies on the effect of urbanization and industrialization on global solar radiation and the percentage values of radiation loss in the atmosphere, at Egypt, have been performed. The high values of LT (5-6 and B (0.48-0.52 lies between Lat. 28°N-30°N, low values of LT<3.5 and B<0.3 below of Lat. 26°N. 8 cities of the thirteen city used in the study are located in the maximum values of this period is the most civilized cities and concentrated a large part of the population which constitutes a danger to the health of the population and the spread of diseases resulting from atmospheric turbidity.

  16. Monthly mean global climatology of temperature, wind, geopotential height and pressure for 0-120 km

    Science.gov (United States)

    Chandra, Sushil; Schoeberl, Mark R.; Fleming, Eric L.; Barnett, John J.

    1990-01-01

    This paper presents a monthly mean climatology of zonal mean temperature, zonal wind, and geopotential height with nearly pole-to-pole coverage (80 deg S-80 deg N) for 0-120 km which can be used as a function of altitude and pressure. This climatology reproduces most of the characteristic features of the atmosphere such as the lowering and cooling of the mesopause and the lowering and warming of the stratopause during the summer months at high latitudes. A series of zonal wind profiles is also presented comparing this climatological wind with monthly mean climatological direct wind measurements in the upper mesosphere and lower thermosphere. The two data sets compare well below 80 km, with some general seasonal trend agreement observed above 80 km. The zonal wind at the equator presented here simulates the observed features of the semiannual oscillation in the upper stratosphere and mesosphere.

  17. Monthly Summaries of the Global Historical Climatology Network - Daily (GHCN-D)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly Summaries of Global Historical Climatology Network (GHCN)-Daily is a dataset derived from GHCN-Daily. The data are produced by computing simple averages or...

  18. SST Anomaly, NOAA POES AVHRR, Casey and Cornillon Climatology, 0.1 degrees, Global

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes SST anomaly data using a combination of the POES AVHRR Global Area Coverage data, and data from a climatological database by Casey and...

  19. East Asian Seas Regional Climatology Version 2.0 from 1804 to 2014 (NODC Accession 0123300)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The East Asian Seas Regional Climatology Version 2.0 is an update to the preliminary version released in May 2012. This update includes new temperature and salinity...

  20. A smart climatology of evaporation duct height and surface radar propagation in the Indian Ocean

    OpenAIRE

    Twigg, Katherine L.

    2007-01-01

    Surface electromagnetic propagation over the ocean is highly sensitive to near-surface atmospheric variability, particularly the height of the evaporation duct. Seasonal variation in near-surface meterological factors and sea surface temperatures impact the evaporation duct height (EDH). Present U.S. Navy EDH climatology is based on sparse ship observations over a relatively short time period and an outdated evaporation duct (ED) model. This EDH climatology does not utilize smart, or modern, ...

  1. Climatology, storm morphologies, and environments of tornadoes in the British Isles: 1980–2012

    OpenAIRE

    Mulder, Kelsey J.; Schultz, David M.

    2015-01-01

    A climatology is developed for tornadoes during 1980–2012 in the British Isles, defined in this article as England, Scotland, Wales, Northern Ireland, Republic of Ireland, Channel Islands, and the Isle of Man. The climatology includes parent storm type, interannual variability, annual and diurnal cycles, intensities, oc- currence of outbreaks (defined as three or more tornadoes in the same day), geographic distribution, and environmental conditions derived from proximity soundings of tornadoe...

  2. Characterizing sampling biases in the trace gas climatologies of the SPARC Data Initiative

    OpenAIRE

    Toohey, Matthew; Hegglin, M. I.; Tegtmeier, Susann; Anderson, J; Añel, J. A.; Bourassa, A.; Brohede, S.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A; Kasai, Y.; Krüger, Kirstin

    2013-01-01

    Monthly zonal mean climatologies of atmospheric measurements from satellite instruments can have biases due to the non-uniform sampling of the atmosphere by the instruments. We characterize potential sampling biases in stratospheric trace gas climatologies of the Stratospheric Processes and their Role in Climate (SPARC) Data Initiative using chemical fields from a chemistry climate model simulation and sampling patterns from 16 satellite-borne instruments. The exercise is performed for the lo...

  3. A global ozone climatology from ozone soundings via trajectory mapping: a stratospheric perspective

    OpenAIRE

    Liu, J.; D. W. Tarasick; V. E. Fioletov; Mclinden, C.; Zhao, T.; Gong, S.; C. Sioris; J. J. Jin; Liu, G.; Moeini, O.

    2013-01-01

    This study explores a domain-filling trajectory approach to generate a global ozone climatology from relatively sparse ozonesonde data. Global ozone soundings comprising 51 898 profiles at 116 stations over 44 yr (1965–2008) are used, from which forward and backward trajectories are calculated from meteorological reanalysis data, to map ozone measurements to other locations and so fill in the spatial domain. The resulting global ozone climatology is archived monthly for five decades fr...

  4. A global ozone climatology from ozone soundings via trajectory mapping: a stratospheric perspective

    OpenAIRE

    Liu, J.; D. W. Tarasick; V. E. Fioletov; Mclinden, C.; Zhao, T.; Gong, S.; C. Sioris; J. J. Jin; Liu, G.; Moeini, O.

    2013-01-01

    This study explores a domain-filling trajectory approach to generate a global ozone climatology from relatively sparse ozonesonde data. Global ozone soundings comprising 51 898 profiles at 116 stations over 44 yr (1965–2008) are used, from which forward and backward trajectories are calculated from meteorological reanalysis data to map ozone measurements to other locations and so fill in the spatial domain. The resulting global ozone climatology is archived monthly for five ...

  5. MERIS albedo climatology for FRESCO+ O2 A-band cloud retrieval

    OpenAIRE

    Zhou, Y.; P. Stammes; Brunner, D.; Wang, P.; Popp, C; M. Grzegorski

    2011-01-01

    A new global albedo climatology for Oxygen A-band cloud retrievals is presented. The climatology is based on MEdium Resolution Imaging Spectrometer (MERIS) Albedomap data and its favourable impact on the derivation of cloud fraction is demonstrated for the FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm. To date, a relatively coarse resolution (1° × 1°) surface reflectance dataset from GOME (Global Ozone Monitoring Experiment) Lambert-equivalent reflectivity (LER) ...

  6. MERIS albedo climatology for FRESCO+ O2 A-band cloud retrieval

    OpenAIRE

    Zhou, Y.; P. Stammes; Brunner, D.; Wang, P.; Popp, C; M. Grzegorski

    2010-01-01

    A new global albedo climatology for Oxygen A-band cloud retrievals is presented. The climatology is based on MEdium Resolution Imaging Spectrometer (MERIS) Albedomap data and its favourable impact on the derivation of cloud fraction is demonstrated for the FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm. To date, a relatively coarse resolution (1° × 1°) surface reflectance dataset from GOME (Global Ozone Monitoring Experiment) Lambert-equivalent reflectivity (LER) ...

  7. An Emerging Global Aerosol Climatology from the MODIS Satellite Sensors

    Science.gov (United States)

    Remer, Lorraine A.; Kleidman, Richard G.; Levy, Robert C.; Kaufman, Yoram J.; Tanre, Didier; Mattoo, Shana; Martins, J. Vandelei; Ichoku, Charles; Koren, Ilan; Hongbin, Yu; Holben, Brent N.

    2008-01-01

    The recently released Collection 5 MODIS aerosol products provide a consistent record of the Earth's aerosol system. Comparison with ground-based AERONET observations of aerosol optical depth (AOD) we find that Collection 5 MODIS aerosol products estimate AOD to within expected accuracy more than 60% of the time over ocean and more than 72% of the time over land. This is similar to previous results for ocean, and better than the previous results for land. However, the new Collection introduces a 0.01 5 offset between the Terra and Aqua global mean AOD over ocean, where none existed previously. Aqua conforms to previous values and expectations while Terra is high. The cause of the offset is unknown, but changes to calibration are a possible explanation. We focus the climatological analysis on the better understood Aqua retrievals. We find that global mean AOD at 550 nm over oceans is 0.13 and over land 0.19. AOD in situations with 80% cloud fraction are twice the global mean values, although such situations occur only 2% of the time over ocean and less than 1% of the time over land. There is no drastic change in aerosol particle size associated with these very cloudy situations. Regionally, aerosol amounts vary from polluted areas such as East Asia and India, to the cleanest regions such as Australia and the northern continents. In almost all oceans fine mode aerosol dominates over dust, except in the tropical Atlantic downwind of the Sahara and in some months the Arabian Sea.

  8. Climatology of Aerosol Optical Properties in Southern Africa

    Science.gov (United States)

    Queface, Antonio J.; Piketh, Stuart J.; Eck, Thomas F.; Tsay, Si-Chee

    2011-01-01

    A thorough regionally dependent understanding of optical properties of aerosols and their spatial and temporal distribution is required before we can accurately evaluate aerosol effects in the climate system. Long term measurements of aerosol optical depth, Angstrom exponent and retrieved single scattering albedo and size distribution, were analyzed and compiled into an aerosol optical properties climatology for southern Africa. Monitoring of aerosol parameters have been made by the AERONET program since the middle of the last decade in southern Africa. This valuable information provided an opportunity for understanding how aerosols of different types influence the regional radiation budget. Two long term sites, Mongu in Zambia and Skukuza in South Africa formed the core sources of data in this study. Results show that seasonal variation of aerosol optical thicknesses at 500 nm in southern Africa are characterized by low seasonal multi-month mean values (0.11 to 0.17) from December to May, medium values (0.20 to 0.27) between June and August, and high to very high values (0.30 to 0.46) during September to November. The spatial distribution of aerosol loadings shows that the north has high magnitudes than the south in the biomass burning season and the opposite in none biomass burning season. From the present aerosol data, no long term discernable trends are observable in aerosol concentrations in this region. This study also reveals that biomass burning aerosols contribute the bulk of the aerosol loading in August-October. Therefore if biomass burning could be controlled, southern Africa will experience a significant reduction in total atmospheric aerosol loading. In addition to that, aerosol volume size distribution is characterized by low concentrations in the non biomass burning period and well balanced particle size contributions of both coarse and fine modes. In contrast high concentrations are characteristic of biomass burning period, combined with

  9. Chemical climatology of the southeastern United States, 1999–2013

    Directory of Open Access Journals (Sweden)

    G. M. Hidy

    2014-06-01

    Full Text Available A series of experiments (the Southern Oxidant and Aerosol Study-SOAS took place in central Alabama in June–July 2013 as part of the broader Southern Atmosphere Study (SAS. These projects were aimed at studying oxidant photochemistry and formation and impacts of aerosols at a detailed process level in a location where high biogenic organic vapor emissions interact with anthropogenic emissions, and the atmospheric chemistry occurs in a subtropical climate in North America. The majority of the ground-based experiments were located at the Southeastern Aerosol Research and Characterization (SEARCH Centreville (CTR site near Brent, Alabama, where extensive, unique aerometric measurements of meteorology, trace gases and particles have been made from the early 1990s through 2013. The SEARCH network data permits a characterization of temporal and spatial context of the SOAS findings. The long-term measurements show that the SOAS experiments took place during the second wettest and coolest year in the 2000–2013 period, with lower than average solar radiation. The pollution levels at CTR and other SEARCH sites were the lowest since full measurements began in 1999. This dataset provides a perspective for the SOAS program in terms of long-term average chemistry (chemical climatology and short-term comparisons of summer average spatial variability across the Southeast at high temporal (hourly resolution. Changes in anthropogenic gas and particle emissions between 1999 and 2013, account for the decline in pollutant concentrations at the monitoring sites in the region. The long-term and short-term data provide an opportunity to contrast SOAS results with temporally and spatially variable conditions in support for the development of tests for the robustness of SOAS findings.

  10. A climatology of formation conditions for aerodynamic contrails

    Directory of Open Access Journals (Sweden)

    K. Gierens

    2013-11-01

    Full Text Available Aircraft at cruise levels can cause two kinds of contrails, the well known exhaust contrails and the less well-known aerodynamic contrails. While the possible climate impact of exhaust contrails has been studied for many years, research on aerodynamic contrails began only a few years ago and nothing is known about a possible contribution of these ice clouds to climate impact. In order to make progress in this respect, we first need a climatology of their formation conditions and this is given in the present paper. Aerodynamic contrails are defined here as line shaped ice clouds caused by aerodynamically triggered cooling over the wings of an aircraft in cruise which become visible immediately at the trailing edge of the wing or close to it. Effects at low altitudes like condensation to liquid droplets and their potential heterogeneous freezing are excluded from our definition. We study atmospheric conditions that allow formation of aerodynamic contrails. These conditions are stated and then applied to atmospheric data: first to a special case where an aerodynamic contrail was actually observed and then to a full year of global reanalysis data. We show where, when (seasonal variation, and how frequently (probability aerodynamic contrails can form, and how this relates to actual patterns of air traffic. We study the formation of persistent aerodynamic contrails as well. Furthermore, we check whether aerodynamic and exhaust contrails can coexist in the atmosphere. We show that visible aerodynamic contrails are possible only in an altitude range between roughly 540 and 250 hPa, and that the ambient temperature is the most important parameter, not the relative humidity. Finally, we argue that currently aerodynamic contrails have a much smaller climate effect than exhaust contrails, which may however change in future with more air traffic in the tropics.

  11. Synoptic climatology of major floods in the Negev Desert, Israel

    Science.gov (United States)

    Kahana, Ron; Ziv, Baruch; Enzel, Yehouda; Dayan, Uri

    2002-06-01

    This study examines the extent to which the floods in the Negev Desert, an area that constitutes the southern half of Israel, are not the outcome of purely local weather conditions but are, rather, the result of distinct synoptic-scale events. This was done through compiling and analysing a hydro-climatological database of all the major floods in the Negev, and then categorizing them manually into synoptic types that cause the major floods.The type analysis is based on the US National Meteorological Center data sets with 2.5° × 2.5° resolution analysed by GrADS. Data were compiled and studied for 52 floods for the period 1965-94, with peak discharge above the magnitude of 5 year recurrence intervals (RI > 5 years) in at least one drainage basin.Distinct extreme synoptic patterns are indeed associated with 42 of the 52 floods. They were grouped into four synoptic types, two of which were associated with 37 events: (a) an active Red Sea trough, defined as a surface trough extending from East Africa through the Red Sea toward the eastern Mediterranean, accompanied by a pronounced trough at the 500 hPa level over eastern Egypt: (b) a Syrian low, defined as a well-developed Mediterranean cyclone accompanied by a pronounced upper-level trough, both located over Syria. Each of the four synoptic types has its own evolution course, and a unique seasonal and spatial distribution of its associated flooded basins.These findings imply that the major floods in the Negev can be considered as signatures of exceptional synoptic-scale evolutions, and that major floods reflect extreme climatic events. Our results indicate that it is possible to use a set of dynamic and thermodynamic variables for predicting the occurrence and location of major flash floods.

  12. A climatology of formation conditions for aerodynamic contrails

    Science.gov (United States)

    Gierens, K.; Dilger, F.

    2013-11-01

    Aircraft at cruise levels can cause two kinds of contrails, the well known exhaust contrails and the less well-known aerodynamic contrails. While the possible climate impact of exhaust contrails has been studied for many years, research on aerodynamic contrails began only a few years ago and nothing is known about a possible contribution of these ice clouds to climate impact. In order to make progress in this respect, we first need a climatology of their formation conditions and this is given in the present paper. Aerodynamic contrails are defined here as line shaped ice clouds caused by aerodynamically triggered cooling over the wings of an aircraft in cruise which become visible immediately at the trailing edge of the wing or close to it. Effects at low altitudes like condensation to liquid droplets and their potential heterogeneous freezing are excluded from our definition. We study atmospheric conditions that allow formation of aerodynamic contrails. These conditions are stated and then applied to atmospheric data: first to a special case where an aerodynamic contrail was actually observed and then to a full year of global reanalysis data. We show where, when (seasonal variation), and how frequently (probability) aerodynamic contrails can form, and how this relates to actual patterns of air traffic. We study the formation of persistent aerodynamic contrails as well. Furthermore, we check whether aerodynamic and exhaust contrails can coexist in the atmosphere. We show that visible aerodynamic contrails are possible only in an altitude range between roughly 540 and 250 hPa, and that the ambient temperature is the most important parameter, not the relative humidity. Finally, we argue that currently aerodynamic contrails have a much smaller climate effect than exhaust contrails, which may however change in future with more air traffic in the tropics.

  13. The International Reference Ionosphere - Climatological Standard for the Ionosphere

    Science.gov (United States)

    Bilitza, Dieter

    2006-01-01

    The International Reference Ionosphere (IRI) a joint project of URSI and COSPAR is the defacto standard for a climatological specification of ionospheric parameters. IRI is based on a wide range of ground and space data and has been steadily improved since its inception in 1969 with the ever-increasing volume of ionospheric data and with better mathematical descriptions of the observed global and temporal variation patterns. The IRI model has been validated with a large amount of data including data from the most recent ionospheric satellites (KOMPSAT, ROCSAT and TIMED) and data from global network of ionosondes. Several IRI teams are working on specific aspects of the IRI modeling effort including an improved representation of the topside ionosphere with a seamless transition to the plasmasphere, a new effort to represent the global variation of F2 peak parameters using the Neural Network (NN) technique, and the inclusion of several additional parameters in IRI, e.g., spread-F probability and ionospheric variability. Annual IRI workshops are the forum for discussions of these efforts and for all science activities related to IRI as well as applications of the IRI model in engineering and education. In this paper I will present a status report about the IRI effort with special emphasis on the presentations and results from the most recent IRI Workshops (Paris, 2004; Tortosa, 2005) and on the most important ongoing IRI activities. I will discuss the latest version of the IRI model, IRI-2006, highlighting the most recent changes and additions. Finally, the talk will review some of the applications of the IRI model with special emphasis on the use for radiowave propagation studies and communication purposes.

  14. Mapping Atmospheric Moisture Climatologies across the Conterminous United States.

    Directory of Open Access Journals (Sweden)

    Christopher Daly

    Full Text Available Spatial climate datasets of 1981-2010 long-term mean monthly average dew point and minimum and maximum vapor pressure deficit were developed for the conterminous United States at 30-arcsec (~800m resolution. Interpolation of long-term averages (twelve monthly values per variable was performed using PRISM (Parameter-elevation Relationships on Independent Slopes Model. Surface stations available for analysis numbered only 4,000 for dew point and 3,500 for vapor pressure deficit, compared to 16,000 for previously-developed grids of 1981-2010 long-term mean monthly minimum and maximum temperature. Therefore, a form of Climatologically-Aided Interpolation (CAI was used, in which the 1981-2010 temperature grids were used as predictor grids. For each grid cell, PRISM calculated a local regression function between the interpolated climate variable and the predictor grid. Nearby stations entering the regression were assigned weights based on the physiographic similarity of the station to the grid cell that included the effects of distance, elevation, coastal proximity, vertical atmospheric layer, and topographic position. Interpolation uncertainties were estimated using cross-validation exercises. Given that CAI interpolation was used, a new method was developed to allow uncertainties in predictor grids to be accounted for in estimating the total interpolation error. Local land use/land cover properties had noticeable effects on the spatial patterns of atmospheric moisture content and deficit. An example of this was relatively high dew points and low vapor pressure deficits at stations located in or near irrigated fields. The new grids, in combination with existing temperature grids, enable the user to derive a full suite of atmospheric moisture variables, such as minimum and maximum relative humidity, vapor pressure, and dew point depression, with accompanying assumptions. All of these grids are available online at http://prism.oregonstate.edu, and

  15. Mapping Atmospheric Moisture Climatologies across the Conterminous United States.

    Science.gov (United States)

    Daly, Christopher; Smith, Joseph I; Olson, Keith V

    2015-01-01

    Spatial climate datasets of 1981-2010 long-term mean monthly average dew point and minimum and maximum vapor pressure deficit were developed for the conterminous United States at 30-arcsec (~800m) resolution. Interpolation of long-term averages (twelve monthly values per variable) was performed using PRISM (Parameter-elevation Relationships on Independent Slopes Model). Surface stations available for analysis numbered only 4,000 for dew point and 3,500 for vapor pressure deficit, compared to 16,000 for previously-developed grids of 1981-2010 long-term mean monthly minimum and maximum temperature. Therefore, a form of Climatologically-Aided Interpolation (CAI) was used, in which the 1981-2010 temperature grids were used as predictor grids. For each grid cell, PRISM calculated a local regression function between the interpolated climate variable and the predictor grid. Nearby stations entering the regression were assigned weights based on the physiographic similarity of the station to the grid cell that included the effects of distance, elevation, coastal proximity, vertical atmospheric layer, and topographic position. Interpolation uncertainties were estimated using cross-validation exercises. Given that CAI interpolation was used, a new method was developed to allow uncertainties in predictor grids to be accounted for in estimating the total interpolation error. Local land use/land cover properties had noticeable effects on the spatial patterns of atmospheric moisture content and deficit. An example of this was relatively high dew points and low vapor pressure deficits at stations located in or near irrigated fields. The new grids, in combination with existing temperature grids, enable the user to derive a full suite of atmospheric moisture variables, such as minimum and maximum relative humidity, vapor pressure, and dew point depression, with accompanying assumptions. All of these grids are available online at http://prism.oregonstate.edu, and include 800-m and 4

  16. UK tornado climatology and the development of simple prediction tools

    Science.gov (United States)

    Holden, J.; Wright, A.

    2004-04-01

    The principle features of tornado climatology in the UK are presented based on the 5-year period from January 1995. Just over one third of reported tornadoes occurred in the south-east region of England, and most tornado activity took place during the spring and summer while the least activity occurred during autumn. This was different to the seasonal distribution for the period from 1960 to 1989 when autumn had the greatest number of tornadoes. The reported tornado distribution was shown to be significantly affected by topography and the density of potential observers. Of the ground-based meteorological variables tested, air temperature was most closely related to tornado occurrence with a peak at 13 deg;C. An equation incorporating air temperature, dew-point temperature, wind speed and pressure was shown to predict a tornado day with an accuracy of 86. 2%. The probability that a tornado would occur on a predicted day was 81. 2%. The model was used to predict actual tornado occurrences across England, Wales and Scotland during the 5-year study period, and it was estimated that just over five-times as many tornadoes occurred than were reported. The model results suggest that the bias induced by population density was not greater than the combined influence of topography and spatial setting. This is important in the UK, because most tornadoes are reported in lowland areas which are heavily populated and it has been difficult until now to determine the extent to which tornado reports are biased by the density of potential observers.

  17. Climatology and a dynamical investigation of tropical cyclogenesis

    Science.gov (United States)

    Asaadi, Ali; Brunet, Gilbert; Yau, Peter M. K.

    2014-05-01

    In general, observation has indicated that only a small fraction of the easterly waves occur in a single hurricane season contribute to tropical cyclogenesis. However, this small fraction includes a large portion of named storms. In addition, it has recently been shown that named storms in the Atlantic and eastern Pacific basins are almost all associated with a cyclonic Kelvin cat's eye of a tropical easterly wave critical layer, located equatorward of the easterly jet axis. Therefore, to better understand the dynamics involved in tropical cyclogenesis, it is desirable to investigate the flow characteristics and the physical mechanism for an easterly wave to form a cat's eye. We have chosen the simplest of all scenarios to present the fundamental concepts of tropical cyclogenesis in a tropical wave critical layer. Our methodology involves performing a climatological study of developing easterly waves covering the 1998-2001 hurricane seasons using ERA-Interim 6-hourly reanalysis data. Spatial and temporal filtering is applied to decompose the desired fields, and time-lagged composites are obtained in a translating reference frame following the disturbances. The stability analysis of the basic state flow has been investigated. The composite basic state zonal wind profiles indicate a cyclonic critical layer at cat's eye formation region. Composite perturbation potential vorticity showed a wave-like pattern, which is in agreement with typical characteristics of easterly waves. Statistical analysis is also used to determine the levels of confidence in the composite fields to assess the reliability of the results. In addition, the total potential vorticity diagnostics show a closed pattern only for one of the easterly wave troughs within the domain, the one associated with the tropical storms, and seem to be a better approach to distinguish developing vs. non-developing disturbances.

  18. Understanding the Rainfall Daily Climatology of Northwestern Mexico

    Science.gov (United States)

    Brito-Castillo, L.

    2007-05-01

    Maximum monthly precipitation (MMP) over northwestern Mexico is not concurrent because it occurs in different months from July through September. However, instead of occurring progressively from one month to the next as latitude increases, as it might be logic since rains move progressively from south to north as monsoon develops, MMP occurs in July in latitudes of Jalisco state, then MMP shifts to August more to the north in latitudes of Nayarit state and along the eastern coast of the Gulf of California, then it occurs in July in higher latitudes through the main axis of the Sierra Madre Occidental (SMO), and finally MMP shifts to September to the west in the California Peninsula. The maximum monthly streamflow occurs in a similar pattern as MMP does but one month later. When daily rainfall climatology of the region is calculated, i.e. the long-term mean per day from stations with more than 20 years of data between 1940 and 2004, it is possible to understand why the behavior of MMP occurs in a July-August-July pattern from south to north. Preliminary results indicate that at latitudes of Nayarit state normal frequent storms with abundant rains develop at the end of July and through the August. These rains sum to the rains that move from the south to the north, as monsoon develops increasing the volume of precipitations at those latitudes in August. To the east crossing the SMO through northwestern Zacatecas state maximum volume of precipitations also is observed in August. However, in higher latitudes it is not observed any increment of rains in August and consequently maximum volume of precipitations occurs in July. To understand the dynamics of the rains at the latitudes of Nayarit state it results necessary to investigate the source of these local rains and explain why the increase of precipitations in August is limited at those latitudes.

  19. NAIRAS aircraft radiation model development, dose climatology, and initial validation

    Science.gov (United States)

    Mertens, Christopher J.; Meier, Matthias M.; Brown, Steven; Norman, Ryan B.; Xu, Xiaojing

    2013-10-01

    The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a real-time, global, physics-based model used to assess radiation exposure to commercial aircrews and passengers. The model is a free-running physics-based model in the sense that there are no adjustment factors applied to nudge the model into agreement with measurements. The model predicts dosimetric quantities in the atmosphere from both galactic cosmic rays (GCR) and solar energetic particles, including the response of the geomagnetic field to interplanetary dynamical processes and its subsequent influence on atmospheric dose. The focus of this paper is on atmospheric GCR exposure during geomagnetically quiet conditions, with three main objectives. First, provide detailed descriptions of the NAIRAS GCR transport and dosimetry methodologies. Second, present a climatology of effective dose and ambient dose equivalent rates at typical commercial airline altitudes representative of solar cycle maximum and solar cycle minimum conditions and spanning the full range of geomagnetic cutoff rigidities. Third, conduct an initial validation of the NAIRAS model by comparing predictions of ambient dose equivalent rates with tabulated reference measurement data and recent aircraft radiation measurements taken in 2008 during the minimum between solar cycle 23 and solar cycle 24. By applying the criterion of the International Commission on Radiation Units and Measurements (ICRU) on acceptable levels of aircraft radiation dose uncertainty for ambient dose equivalent greater than or equal to an annual dose of 1 mSv, the NAIRAS model is within 25% of the measured data, which fall within the ICRU acceptable uncertainty limit of 30%. The NAIRAS model predictions of ambient dose equivalent rate are generally within 50% of the measured data for any single-point comparison. The largest differences occur at low latitudes and high cutoffs, where the radiation dose level is low. Nevertheless, analysis suggests

  20. A lightning climatology of the South-West Indian Ocean

    Directory of Open Access Journals (Sweden)

    C. Bovalo

    2012-08-01

    Full Text Available The World Wide Lightning Location Network (WWLLN data have been used to perform a lightning climatology in the South-West Indian Ocean (SWIO region from 2005 to 2011. Maxima of lightning activity were found in the Maritime Continent and southwest of Sri Lanka (>50 fl km−2 yr−1 but also over Madagascar and above the Great Lakes of East Africa (>10–20 fl km−2 yr−1. Lightning flashes within tropical storms and tropical cyclones represent 50 % to 100 % of the total lightning activity in some oceanic areas of the SWIO (between 10° S and 20° S.

    The SWIO is characterized by a wet season (November to April and a dry season (May to October. As one could expect, lightning activity is more intense during the wet season as the Inter Tropical Convergence Zone (ITCZ is present over all the basin. Flash density is higher over land in November–December–January with values reaching 3–4 fl km−2 yr−1 over Madagascar. During the dry season, lightning activity is quite rare between 10° S and 25° S. The Mascarene anticyclone has more influence on the SWIO resulting in shallower convection. Lightning activity is concentrated over ocean, east of South Africa and Madagascar.

    A statistical analysis has shown that El Niño–Southern Oscillation mainly modulates the lightning activity up to 56.8% in the SWIO. The Indian Ocean Dipole has a significant contribution since ~49% of the variability is explained by this forcing in some regions. The Madden–Julian Oscillation did not show significative impact on the lightning activity in our study.

  1. The Global Precipitation Climatology Project (GPCP): Results, Status and Future

    Science.gov (United States)

    Adler, Robert F.

    2007-01-01

    The Global Precipitation Climatology Project (GPCP) is one of a number of long-term, satellite-based, global analyses routinely produced under the auspices of the World Climate Research Program (WCRP) and its Global Energy and Watercycle EXperiment (GEWEX) program. The research quality analyses are produced a few months after real-time through the efforts of scientists at various national agencies and universities in the U.S., Europe and Japan. The primary product is a monthly analysis of surface precipitation that is globally complete and spans the period 1979-present. There are also pentad analyses for the same period and a daily analysis for the 1997-present period. Although generated with somewhat different data sets and analysis schemes, the pentad and daily data sets are forced to agree with the primary monthly analysis on a grid box by grid box basis. The primary input data sets are from low-orbit passive microwave observations, geostationary infrared observations and surface raingauge information. Examples of research with the data sets are discussed, focusing on tropical (25N-25s) rainfall variations and possible long-term changes in the 28-year (1979-2006) monthly dataset. Techniques are used to discriminate among the variations due to ENSO, volcanic events and possible long-term changes for rainfall over both land and ocean. The impact of the two major volcanic eruptions over the past 25 years is estimated to be about a 5% maximum reduction in tropical rainfall during each event. Although the global change of precipitation in the data set is near zero, a small upward linear change over tropical ocean (0.06 mm/day/l0yr) and a slight downward linear change over tropical land (-0.03 mm/day/l0yr) are examined to understand the impact of the inhomogeneity in the data record and the length of the data set. These positive changes correspond to about a 5% increase (ocean) and 3% increase (ocean plus land) during this time period. Relations between variations in

  2. European drought climatologies for the period 1950 to 2012

    Science.gov (United States)

    Spinoni, Jonathan; Naumann, Gustavo; Vogt, Jürgen V.; Barbosa, Paulo

    2014-05-01

    In the context of global climate change, characterized in particular by rising temperatures and more extreme weather events, drought is one of the most relevant natural disasters that has hit Europe frequently in the last decades. This paper presents climatologies of a set of drought indicators and derived drought characteristics at European scale for the period 1950-2012. Following the definitions in Spinoni et al. (2013), we computed drought frequency, duration, severity, and maximum intensity on a grid with spatial resolution of 0.25°x0.25°. Calculations have been based on three well-known drought indicators calculated for time scales of 3 and 12 months: the Standardized Precipitation Index (SPI), the Standardized Precipitation-Evapotranspiration Index (SPEI), and the Reconnaissance Drought Index (RDI). Indicators have been calculated on a monthly basis for the period 1951-2012, using statistical distributions fitted to a 30-year baseline period (1971-2000). Input data stem from the E-OBS (version 9.0) European grids (0.25°x0.25°) provided by the Royal Meteorological Service of The Netherlands (KNMI). Monthly precipitation data served as input for all indicators, while mean monthly temperature data were used to calculate Thornthwaite's potential evapotranspiration necessary to calculate SPEI and RDI. On the basis of these indicators, we then quantified, on a monthly basis, the total European area under meteorological drought conditions from 1950 to 2012 and their intensity. We further sub-divided Europe into 14 regions according to geographical borders and climatic features and for each of them we computed linear trends of different drought characteristics (i.e. frequency, duration, severity, and intensity) for the entire period, and for the sub-periods 1951-1980 and 1981-2010. Results show that the Mediterranean, the Balkans, and Eastern Europe are characterized by increasing drought frequency, duration, severity, and maximum intensity, while Russia and

  3. A Climatological Investigation of the Activity of Summer Subtropical Vortices

    Institute of Scientific and Technical Information of China (English)

    LUO Zhexian; DAI Kan

    2008-01-01

    By applying a new vortex detection method to the ECMWF 40-yr reanalysis (ERA40) data from 1985 to 2002, the climatology of summer vortices has been investigated in five subtropical regions, i.e., the northwestern Pacific, northeastern Pacific, northwestern Atlantic, northeastern Atlantic, and Australia-South Pacific, followed by validation with NCEP/NCAR reanalysis data. Results are as follows: (1) The spatial distributions of ERA40 vortex activities (VAC) were well consistent with those of NCEP/NCAR reanalysis (NRA) results in all regions, especially in northwestern Pacific. (2) Because of different model resolutions, both the number and intensity of vortices obtained from NRA were significantly weaker thanERA40's. (3) Vortices mainly cruised in coasts and the adjacent seas, from where to the land or the open sea vortex activities were gradually decreased. (4) There were two active centers in the northwestern Pacific:one was located in South China Sea and the other, as the largest center of the five regions, spread from the east side of the Philippines to Japan. (5) Over the northwestern Atlantic, most vortices occurred in Panama and its west-side offshore. (6) The spatial distributions of vortices were alike between the northeastern Pacific and northeastern Atlantic, both spreading from coasts to the west-side sea at 5°-20°N. (7) In the Anstralia-South Pacific, vortices were not as active as those in the other four regions, and mostly took place in the equator-side of near ocean areas. (8) Except the northwestern Pacific and northwestern Atlantic, the VAC interannual variations in the other three regions were different between ERA40 and NRA data. (9)In the northwestern Pacific and northwestern Atlantic, the VAC interannual variation could be separated to several distinct stages. (10) Since the mid 1980s, mean vortex intensity was getting increased in the northwestern Pacific, which was most significant in the subtropical areas on a global basis. In the western

  4. Uncertainties in calculating precipitation climatology in East Asia

    Science.gov (United States)

    Kim, J.; Park, S. K.

    2016-02-01

    This study examines the uncertainty in calculating the fundamental climatological characteristics of precipitation in the East Asia region from multiple fine-resolution gridded analysis data sets based on in situ rain gauge observations and data assimilations. Five observation-based gridded precipitation data sets are used to derive the long-term means, standard deviations in lieu of interannual variability and linear trends over the 28-year period from 1980 to 2007. Both the annual and summer (June-July-August) mean precipitation is examined. The agreement amongst these precipitation data sets is examined using two metrics including the signal-to-noise ratio (SNR) defined as the ratio between long-term means and the corresponding standard deviations, and Taylor diagrams, which allow examinations of the pattern correlation, the standard deviation, and the centered root mean square error. It is found that the five gauge-based precipitation analysis data sets agree well in the long-term mean and interannual variability in most of the East Asia region including eastern China, Manchuria, South Korea, and Japan, which are densely populated and have fairly high-density observation networks. The regions of large inter-data-set variations include Tibetan Plateau, Mongolia, northern Indo-China, and North Korea. The regions of large uncertainties are typically lightly populated and are characterized by severe terrain and/or extremely high elevations. Unlike the long-term mean and interannual variability, agreement between data sets in the linear trend is weak, both for the annual and summer mean values. In most of the East Asia region, the SNR for the linear trend is below 0.5: the inter-data-set variability exceeds the multi-data ensemble mean. The uncertainty in the spatial distribution of long-term means among these data sets occurs both in the spatial pattern and variability, but the uncertainty for the interannual variability and time trend is much larger in the

  5. High Resolution Hydro-climatological Projections for Western Canada

    Science.gov (United States)

    Erler, Andre Richard

    Accurate identification of the impact of global warming on water resources and hydro-climatic extremes represents a significant challenge to the understanding of climate change on the regional scale. Here an analysis of hydro-climatic changes in western Canada is presented, with specific focus on the Fraser and Athabasca River basins and on changes in hydro-climatic extremes. The analysis is based on a suite of simulations designed to characterize internal variability, as well as model uncertainty. A small ensemble of Community Earth System Model version 1 (CESM1) simulations was employed to generate global climate projections, which were downscaled to 10 km resolution using the Weather Research and Forecasting model (WRF V3.4.1) with several sets of physical parameterizations. Downscaling was performed for a historical validation period and a mid- and end-21st-century projection period, using the RCP8.5 greenhouse gas trajectory. Daily station observations and monthly gridded datasets were used for validation. Changes in hydro-climatic extremes are characterized using Extreme Value Analysis. A novel method of aggregating data from climatologically similar stations was employed to increase the statistical power of the analysis. Changes in mean and extreme precipitation are found to differ strongly between seasons and regions, but (relative) changes in extremes generally follow changes in the (seasonal) mean. At the end of the 21st century, precipitation and precipitation extremes are projected to increase by 30% at the coast in fall and land-inwards in winter, while the projected increase in summer precipitation is smaller and changes in extremes are often not statistically significant. Reasons for the differences between seasons, the role of precipitation recycling in atmospheric water transport, and the sensitivity to physics parameterizations are discussed. Major changes are projected for the Fraser River basin, including earlier snowmelt and a 50% reduction in

  6. Assessing Extremes Climatology Using NWS Local Climate Analysis Tool

    Science.gov (United States)

    Timofeyeva, M. M.; Hollingshead, A.; Hilderbrand, D.; Mayes, B.; Hartley, T.; Kempf McGavock, N. M.; Lau, E.; Olenic, E. A.; Motta, B.; Bunge, R.; Brown, L. E.; Fritsch, F.

    2010-12-01

    The Local Climate Analysis Tool (LCAT) is evolving out of a need to support and enhance the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) field offices’ ability to access, manipulate, and interpret local climate data and characterize climate variability and change impacts. LCAT will enable NWS Regional Headquarters, Weather Forecast Offices, Weather Service Offices, and River Forecast Centers the ability to conduct regional and local climate studies using station and reanalysis gridded data and various statistical techniques for climate analysis. The analysis results will be used for climate services to guide local decision makers in weather and climate sensitive actions and to deliver information to the general public. Field offices need standardized, scientifically sound methodology for local climate analysis (such as trend, composites, and principal statistical and time-series analysis) that is comprehensive, accessible, and efficient, with the potential to expand with growing NOAA Climate Services needs. The methodology for climate analyses is practiced by the NWS Climate Prediction Center (CPC), NOAA National Climatic Data Center, and NOAA Earth System Research Laboratory, as well as NWS field office staff. LCAT will extend this practice at the local level, allowing it to become both widespread and standardized, and thus improve NWS climate services capabilities. LCAT focus is on the local scale (as opposed to national and global scales of CPC products). The LCAT will: -Improve professional competency of local office staff and expertise in providing local information to their users. LCAT will improve quality of local climate services -Ensure adequate local input to CPC products that depend on local information, such as the U.S. Drought Monitor. LCAT will allow improvement of CPC climate products -Allow testing of local climate variables beyond temperature averages and precipitation totals such as climatology of

  7. Nature and climatology of Pfänderwind

    Directory of Open Access Journals (Sweden)

    Alexander Gohm

    2015-04-01

    Full Text Available The characteristics and climatology of Pfänderwind, a largely unknown downslope windstorm near the town of Bregenz (Austria at the entrance of the Rhine Valley, are investigated based on an eleven-year dataset of weather station observations and ERA-Interim reanalyses. The goal is to clarify the inconsistency in the definition of this phenomenon, to illuminate its dynamics, and to quantify its frequency of occurrence. It is shown that Pfänderwind has similarities to foehn but does occur for different synoptic-scale conditions. Moreover, two types of Pfänderwind have to be distinguished: Type 1, or classical Pfänderwind, is associated with easterly to northeasterly large-scale flow that crosses the Pfänder mountain range, descends in a foehn-like manner and causes moderate to strong winds in the town of Bregenz and its vicinity. The temperature anomaly induced at the surface by adiabatic warming is small as a result of weak low-level stability. Type-1 events occur on average 12 times per year, preferentially in spring, and most frequently between the afternoon and midnight. Type 2, or southeast Pfänderwind, is associated with westerly to southwesterly ambient winds near the main Alpine crest level. The Rhine valley is filled with cold air and in most cases south foehn is not present. However, the synoptic and meso-scale pressure gradient favours southerly ageostrophic flow in the Rhine Valley especially near the top of the cold-air pool. This flow passes the Gebhardsberg, the southwestern extension of the Pfänder mountain range, descends on its leeward side and causes strong foehn-like warming at the surface. However, southerly to southeasterly near-surface winds at Bregenz are rather weak. Type-2 events occur on average 40 times per year, most frequently between the evening and the early morning, and exhibit a weak seasonal dependence. More than half of all type-1 and type-2 events last only one or two hours.

  8. A Global Ozone Climatology from Ozone Soundings via Trajectory Mapping: A Stratospheric Perspective

    Science.gov (United States)

    Liu, J. J.; Tarasick, D. W.; Fioletov, V. E.; McLinden, C.; Zhao, T.; Gong, S.; Sioris, G.; Jin, J. J.; Liu, G.; Moeini, O.

    2013-01-01

    This study explores a domain-filling trajectory approach to generate a global ozone climatology from sparse ozonesonde data. Global ozone soundings of 51,898 profiles at 116 stations over 44 years (1965-2008) are used, from which forward and backward trajectories are performed for 4 days, driven by a set of meteorological reanalysis data. Ozone mixing ratios of each sounding from the surface to 26 km altitude are assigned to the entire path along the trajectory. The resulting global ozone climatology is archived monthly for five decades from the 1960s to the 2000s with grids of 5 degree 5 degree 1 km (latitude, longitude, and altitude). It is also archived yearly from 1965 to 2008. This climatology is validated at 20 ozonesonde stations by comparing the actual ozone sounding profile with that found through the trajectories, using the ozone soundings at all the stations except one being tested. The two sets of profiles are in good agreement, both individually with correlation coefficients between 0.975 and 0.998 and root mean square (RMS) differences of 87 to 482 ppbv, and overall with a correlation coefficient of 0.991 and an RMS of 224 ppbv. The ozone climatology is also compared with two sets of satellite data, from the Satellite Aerosol and Gas Experiment (SAGE) and the Optical Spectrography and InfraRed Imager System (OSIRIS). Overall, the ozone climatology compares well with SAGE and OSIRIS data by both seasonal and zonal means. The mean difference is generally under 20 above 15 km. The comparison is better in the northern hemisphere, where there are more ozonesonde stations, than in the southern hemisphere; it is also better in the middle and high latitudes than in the tropics, where assimilated winds are imperfect in some regions. This ozone climatology can capture known features in the stratosphere, as well as seasonal and decadal variations of these features. Furthermore, it provides a wealth of detail about longitudinal variations in the stratosphere such

  9. A global ozone climatology from ozone soundings via trajectory mapping: a stratospheric perspective

    Directory of Open Access Journals (Sweden)

    J. Liu

    2013-06-01

    Full Text Available This study explores a domain-filling trajectory approach to generate a global ozone climatology from relatively sparse ozonesonde data. Global ozone soundings comprising 51 898 profiles at 116 stations over 44 yr (1965–2008 are used, from which forward and backward trajectories are calculated from meteorological reanalysis data, to map ozone measurements to other locations and so fill in the spatial domain. The resulting global ozone climatology is archived monthly for five decades from the 1960s to the 2000s on a~grid of 5° × 5° × 1 km (latitude, longitude, and altitude, from the surface to 26 km altitude. It is also archived yearly from 1965 to 2008. The climatology is validated at 20 selected ozonesonde stations by comparing the actual ozone sounding profile with that derived through trajectory mapping of ozone sounding data from all stations except the one being compared. The two sets of profiles are in good agreement, both individually with correlation coefficients (r between 0.975 and 0.998 and root mean square (RMS differences of 87 to 482 ppbv, and overall with r = 0.991 and an RMS of 224 ppbv. The ozone climatology is also compared with two sets of satellite data, from the Satellite Aerosol and Gas Experiment (SAGE and the Optical Spectrography and InfraRed Imager System (OSIRIS. The ozone climatology compares well with SAGE and OSIRIS data in both seasonal and zonal means. The mean differences are generally quite small, with maximum differences of 20% above 15 km. The agreement is better in the Northern Hemisphere, where there are more ozonesonde stations, than in the Southern Hemisphere; it is also better in the middle and high latitudes than in the tropics where reanalysis winds are less accurate. This ozone climatology captures known features in the stratosphere, as well as seasonal and decadal variations of these features. Compared to current satellite data, it offers more complete high latitude coverage as well as a much

  10. On the climatological probability of the vertical propagation of stationary planetary waves

    Science.gov (United States)

    Karami, Khalil; Braesicke, Peter; Sinnhuber, Miriam; Versick, Stefan

    2016-07-01

    We introduce a diagnostic tool to assess a climatological framework of the optimal propagation conditions for stationary planetary waves. Analyzing 50 winters using NCEP/NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research) reanalysis data we derive probability density functions (PDFs) of positive vertical wave number as a function of zonal and meridional wave numbers. We contrast this quantity with classical climatological means of the vertical wave number. Introducing a membership value function (MVF) based on fuzzy logic, we objectively generate a modified set of PDFs (mPDFs) and demonstrate their superior performance compared to the climatological mean of vertical wave number and the original PDFs. We argue that mPDFs allow an even better understanding of how background conditions impact wave propagation in a climatological sense. As expected, probabilities are decreasing with increasing zonal wave numbers. In addition we discuss the meridional wave number dependency of the PDFs which is usually neglected, highlighting the contribution of meridional wave numbers 2 and 3 in the stratosphere. We also describe how mPDFs change in response to strong vortex regime (SVR) and weak vortex regime (WVR) conditions, with increased probabilities of the wave propagation during WVR than SVR in the stratosphere. We conclude that the mPDFs are a convenient way to summarize climatological information about planetary wave propagation in reanalysis and climate model data.

  11. A new global interior ocean mapped climatology: the 1° × 1° GLODAP version 2

    Science.gov (United States)

    Lauvset, Siv K.; Key, Robert M.; Olsen, Are; van Heuven, Steven; Velo, Anton; Lin, Xiaohua; Schirnick, Carsten; Kozyr, Alex; Tanhua, Toste; Hoppema, Mario; Jutterström, Sara; Steinfeldt, Reiner; Jeansson, Emil; Ishii, Masao; Perez, Fiz F.; Suzuki, Toru; Watelet, Sylvain

    2016-08-01

    We present a mapped climatology (GLODAPv2.2016b) of ocean biogeochemical variables based on the new GLODAP version 2 data product (Olsen et al., 2016; Key et al., 2015), which covers all ocean basins over the years 1972 to 2013. The quality-controlled and internally consistent GLODAPv2 was used to create global 1° × 1° mapped climatologies of salinity, temperature, oxygen, nitrate, phosphate, silicate, total dissolved inorganic carbon (TCO2), total alkalinity (TAlk), pH, and CaCO3 saturation states using the Data-Interpolating Variational Analysis (DIVA) mapping method. Improving on maps based on an earlier but similar dataset, GLODAPv1.1, this climatology also covers the Arctic Ocean. Climatologies were created for 33 standard depth surfaces. The conceivably confounding temporal trends in TCO2 and pH due to anthropogenic influence were removed prior to mapping by normalizing these data to the year 2002 using first-order calculations of anthropogenic carbon accumulation rates. We additionally provide maps of accumulated anthropogenic carbon in the year 2002 and of preindustrial TCO2. For all parameters, all data from the full 1972-2013 period were used, including data that did not receive full secondary quality control. The GLODAPv2.2016b global 1° × 1° mapped climatologies, including error fields and ancillary information, are available at the GLODAPv2 web page at the Carbon Dioxide Information Analysis Center (CDIAC; doi:10.3334/CDIAC/OTG.NDP093_GLODAPv2).

  12. Tennessee Valley Total and Cloud-to-Ground Lightning Climatology Comparison

    Science.gov (United States)

    Buechler, Dennis; Blakeslee, R. J.; Hall, J. M.; McCaul, E. W.

    2008-01-01

    The North Alabama Lightning Mapping Array (NALMA) has been in operation since 2001 and consists often VHF receivers deployed across northern Alabama. The NALMA locates sources of impulsive VHF radio signals from total lightning by accurately measuring the time that the signals arrive at the different receiving stations. The sources detected are then clustered into flashes by applying spatially and temporally constraints. This study examines the total lightning climatology of the region derived from NALMA and compares it to the cloud-to-ground (CG) climatology derived from the National Lightning Detection Network (NLDN) The presentation compares the total and CG lightning trends for monthly, daily, and hourly periods.

  13. The Increasing Use of Remote Sensing Data in Studying the Climatological Impacts on Public Health

    Science.gov (United States)

    Kempler, Steven; Benedict, Karl; Ceccato, Pietro; Golden, Meredith; Maxwell, Susan; Morian, Stan; Soebiyanto, Radina; Tong, Daniel

    2011-01-01

    One of the more fortunate outcomes of the capture and transformation of remote sensing data into applied information is their usefulness and impacts to better understanding climatological impacts on public health. Today, with petabytes of remote sensing data providing global coverage of climatological parameters, public health research and policy decision makers have an unprecedented (and growing) data record that relates the effects of climatic parameters, such as rainfall, heat, soil moisture, etc. to incidences and spread of disease, as well as predictive modeling. In addition, tools and services that specifically serve public health researchers and respondents have grown in response to needs of the these information users.

  14. Water mass census in the Nordic seas using climatological and observational data sets

    International Nuclear Information System (INIS)

    We have compared and evaluated the water mass census in the Greenland-Iceland-Norwegian (Gin) Sea area from climatologies, observational data sets and model output. The four climatologies evaluated were: the 1998 and 2001 versions of the World Ocean Atlas (WOA98, WOA01), and the United States Navy's GDEM90 (Generalized Digital Environmental Model) and MODAS01 (Modular Ocean Data Assimilation System) climatologies. Three observational data sets were examined: the multidecadal (1965-1995) set contained on the National Oceano- graphic Data Centre's (NODC) WOD98 (World Ocean Data) Cd-Rom, and two seasonal data sets extracted from observations taken on six cruises by the SACLANT Research Center (SACLANTCEN) of NATO/Italy between 1986-1989. The model data is extracted from a global model run at 1/3 degree resolution for the years 1983-1997, using the Pop (Parallel Ocean Program) model of the Los Alamos National Laboratory. The census computations focused on the Norwegian Sea, in the southern part of the Gin Sea, between 100W-100E and 600N-700N, especially for comparisons with the hydro casts and the model. Cases of such evaluation computations included: (a) short term comparisons with quasi-synoptic CTD surveys carried out over a 4-year period in the southeastern Gin Sea; (b) climatological comparisons utilizing all available casts from the WOD98 Cd-Rom, with four climatologies; and (c) a comparison between the WOA01 climatology and the Pop model output ending in 1997. In this region in the spring, the fraction of ocean water that has salinity above 34.85 is ∼94%, and that has temperatures above 00C is ∼33%. Three principal water masses dominated the census: the Atlantic water A W, the deep water D W and an intermediate water mass defined as Lower Arctic Intermediate Water (LAIW). Besides these classes, both the climatologies and the observations exhibited the significant presence of deep water masses with T-S characteristics that do not fall into the named varieties

  15. A Meso-Climatology Study of the High-Resolution Tower Network Over the Florida Spaceport

    Science.gov (United States)

    Case, Jonathan L.; Bauman, William H., III

    2004-01-01

    Forecasters at the US Air Force 45th Weather Squadron (45 WS) use wind and temperature data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria and to issue and verify temperature and wind advisories, watches, and warnings for ground operations. The Spaceflight Meteorology Group at the Johnson Space Center in Houston, TX also uses these data when issuing forecasts for shuttle landings at the KSC Shuttle Landing Facility. Systematic biases in these parameters at any of the towers could adversely affect an analysis, forecast, or verification for all of these operations. In addition, substantial geographical variations in temperature and wind speed can occur under specific wind directions. Therefore, the Applied Meteorology Unit (AMU), operated by ENSCO Inc., was tasked to develop a monthly and hourly climatology of temperatures and winds from the tower network, and identify the geographical variation, tower biases, and the magnitude of those biases. This paper presents a sub-set of results from a nine-year climatology of the KSC/CCAFS tower network, highlighting the geographical variations based on location, month, times of day, and specific wind direction regime. Section 2 provides a description of the tower mesonetwork and instrumentation characteristics. Section 3 presents the methodology used to construct the tower climatology including QC methods and data processing. The results of the tower climatology are presented in Section 4 and Section 5 summarizes the paper.

  16. Uncertainty in Climatology-Based Estimates of Soil Water Infiltration Losses

    Science.gov (United States)

    Local climatology is often used to estimate infiltration losses at the field scale. The objective of this work was to assess the uncertainty associated with such estimates. We computed infiltration losses from the water budget of a soil layer from monitoring data on water flux values at the soil su...

  17. Offshore wind climatology based on synergetic use of Envisat ASAR, ASCAT and QuikSCAT

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Mouche, Alexis; Badger, Merete;

    2015-01-01

    The offshore wind climatology in the Northern European seas is analysed from ten years of Envisat synthetic aperture radar (SAR) images using a total of 9256 scenes, ten years of QuikSCAT and two years of ASCAT gridded ocean surface vector wind products and high-quality wind observations from four...

  18. Synoptic-climatological evaluation of the classifications of atmospheric circulation patterns over Europe

    Czech Academy of Sciences Publication Activity Database

    Huth, Radan; Beck, Ch.; Kučerová, Monika

    -, - (2016). ISSN 0899-8418 R&D Projects: GA ČR(CZ) GPP209/12/P811 Institutional support: RVO:68378289 Keywords : circulation types * classification * synoptic climatology * COST733 Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.157, year: 2014 http://onlinelibrary.wiley.com/doi/10.1002/joc.4546/full

  19. U.S. West Coast MODIS Aqua High Resolution CHLA Climatology Fields (July 2002 - March 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This suite of CHLA and SST climatology and anomaly data products are derived from daily, 0.0125 degree x 0.0125 degree, MODIS Aqua CHLA and SST fields that cover...

  20. U.S. West Coast MODIS Aqua High Resolution SST Climatology Fields (July 2002 - March 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This suite of CHLA and SST climatology and anomaly data products are derived from daily, 0.0125 degree x 0.0125 degree, MODIS Aqua CHLA and SST fields that cover...

  1. A global climatology for equatorial plasma bubbles in the topside ionosphere

    Directory of Open Access Journals (Sweden)

    L. C. Gentile

    2006-03-01

    Full Text Available We have developed a global climatology of equatorial plasma bubble (EPB occurrence based on evening sector plasma density measurements from polar-orbiting Defense Meteorological Satellite Program (DMSP spacecraft during 1989-2004. EPBs are irregular plasma density depletions in the post-sunset ionosphere that degrade communication and navigation signals. More than 14400 EPBs were identified in ~134000 DMSP orbits. DMSP observations basically agree with Tsunoda's (1985 hypothesis that EPB rates peak when the terminator is aligned with the Earth's magnetic field, but there are also unpredicted offsets in many longitude sectors. We present an updated climatology for the full database from 1989-2004 along with new plots for specific phases of the solar cycle: maximum 1989-1992 and 1999-2002, minimum 1994-1997, and transition years 1993, 1998, and 2003. As expected, there are significant differences between the climatologies for solar maximum and minimum and between the two solar maximum phases as well. We also compare DMSP F12, F14, F15, and F16 observations at slightly different local times during 2000-2004 to examine local time effects on EPB rates. The global climatologies developed using the DMSP EPB database provide an environmental context for the long-range prediction tools under development for the Communication/Navigation Outage Forecasting System (C/NOFS mission.

  2. Development and Testing of the New Surface LER Climatology for OMI UV Aerosol Retrievals

    Science.gov (United States)

    Gupta, Pawan; Torres, Omar; Jethva, Hiren; Ahn, Changwoo

    2014-01-01

    Ozone Monitoring Instrument (OMI) onboard Aura satellite retrieved aerosols properties using UV part of solar spectrum. The OMI near UV aerosol algorithm (OMAERUV) is a global inversion scheme which retrieves aerosol properties both over ocean and land. The current version of the algorithm makes use of TOMS derived Lambertian Equivalent Reflectance (LER) climatology. A new monthly climatology of surface LER at 354 and 388 nm have been developed. This will replace TOMS LER (380 nm and 354nm) climatology in OMI near UV aerosol retrieval algorithm. The main objectives of this study is to produce high resolution (quarter degree) surface LER sets as compared to existing one degree TOMS surface LERs, to product instrument and wavelength consistent surface climatology. Nine years of OMI observations have been used to derive monthly climatology of surface LER. MODIS derived aerosol optical depth (AOD) have been used to make aerosol corrections on OMI wavelengths. MODIS derived BRDF adjusted reflectance product has been also used to capture seasonal changes in the surface characteristics. Finally spatial and temporal averaging techniques have been used to fill the gaps around the globes, especially in the regions with consistent cloud cover such as Amazon. After implementation of new surface data in the research version of algorithm, comparisons of AOD and single scattering albedo (SSA) have been performed over global AERONET sites for year 2007. Preliminary results shows improvements in AOD retrievals globally but more significance improvement were observed over desert and bright locations. We will present methodology of deriving surface data sets and will discuss the observed changes in retrieved aerosol properties with respect to reference AERONET measurements.

  3. Flux Footprint Climatology Estimated by Three Analytical Models over a Subtropical Coniferous Plantation in Southeast China

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Spatial heterogeneity poses a major challenge for the appropriate interpretation of eddy covariance data. The quantification of footprint climatology is fundamental to improving our understanding of carbon budgets, assessing the quality of eddy covariance data, and upscaling the representativeness of a tower fl ux to regional or global scales. In this study, we elucidated the seasonal variation of fl ux footprint climatologies and the major factors that infl uence them using the analytical FSAM (Flux Source Area Model), KM (Kormann and Meixner, 2001), and H (Hsieh et al., 2000) models based on eddy covariance measurements at two and three times the canopy height at the Qianyanzhou site of ChinaFLUX in 2003. The diff erences in footprints among the three models resulted from diff erent underlying theories used to construct the models. A comparison demonstrated that atmospheric stability was the main factor leading to diff erences among the three models. In neutral and stable conditions, the KM and FSAM values agreed with each other, but they were both lower than the H values. In unstable conditions, the agreement among the three models for rough surfaces was better than that for smooth surfaces, and the models showed greater agreement for a low measurement height than for a high measurement height. The seasonal fl ux footprint climatologies were asymmetrically distributed around the tower and corresponded well to the prevailing wind direction, which was north-northwest in winter and south-southeast in summer. The average sizes of the 90% fl ux footprint climatologies were 0.36–0.74 and 1.5–3.2 km2 at altitudes of two and three times the canopy height, respectively. The average sizes were ranked by season as follows: spring > summer > winter >autumn. The footprint climatology depended more on atmospheric stability on daily scale than on seasonal scale, and it increased with the increasing standard deviation of the lateral wind fl uctuations.

  4. Climatological Analysis of the Exclusive Economic Zone of Mexico Based on 10 Years of Satellite Imagery

    Science.gov (United States)

    Gonzalez Rodriguez, E.; Trasviña-Castro, A.; Aguirre Bahena, F.

    2013-05-01

    To visualize the variability of inorganic carbon in the waters of the Exclusive Economic Zone of Mexico we analysed over 10 years of monthly data 4-km resolution from the MODIS-AQUA satellite. This sensor provides various types of information and for this discussion we selected particulate organic carbon, sea surface temperature and euphotic zone depth. We constructed climatological maps for each month of the year to show the average, maximum, minimum and standard deviation of the three variables. The result of the average particulate organic carbon climatology indicates that the main areas of inorganic carbon production (> 200 mg m3) are the Gulf of California, the west coast of the peninsula of Baja California, the coast of Colima, the Gulf of Tehuantepec and in the Gulf of Mexico the coasts of Yucatan, Tabasco and Tamaulipas. The months presenting higher production occur between December and April. In comparison, lowest climatological mean sea surface temperature (below 14 oC) occurs on the west coast of the Baja California peninsula and it is observed associated with the highest mean particulate organic carbon (>250 mg m-3). Climatological mean sea surface temperature on the coast of Colima, Yucatan, Tabasco and Tamaulipas are about 25 °C and coincide with high values of particulate organic carbon (> 200 mg m-3). The climatological mean euphotic zone depth show lowest values (California, the coast of Colima and the Gulf of Tehuantepec. In the west coast of the peninsula of Baja California greater variability of particulate organic carbon occurs from June to December. In the oceanic domain beyond the continental shelf, particulate organic carbon values are very low (low temperatures and/or low depths of the euphotic zone. The oceanic region shows maximum values for both sea surface temperatures and depth of the euphotic zone as is to be expected in oligotrophic regions of the sea. Anomalies for all three variables will also shown to discuss the interannual

  5. A new global interior ocean mapped climatology: the 1° × 1° GLODAP version 2

    Science.gov (United States)

    Lauvset, Siv K.; Key, Robert M.; Olsen, Are; van Heuven, Steven; Velo, Anton; Lin, Xiaohua; Schirnick, Carsten; Kozyr, Alex; Tanhua, Toste; Hoppema, Mario; Jutterström, Sara; Steinfeldt, Reiner; Jeansson, Emil; Ishii, Masao; Perez, Fiz F.; Suzuki, Toru; Watelet, Sylvain

    2016-08-01

    We present a mapped climatology (GLODAPv2.2016b) of ocean biogeochemical variables based on the new GLODAP version 2 data product (Olsen et al., 2016; Key et al., 2015), which covers all ocean basins over the years 1972 to 2013. The quality-controlled and internally consistent GLODAPv2 was used to create global 1° × 1° mapped climatologies of salinity, temperature, oxygen, nitrate, phosphate, silicate, total dissolved inorganic carbon (TCO2), total alkalinity (TAlk), pH, and CaCO3 saturation states using the Data-Interpolating Variational Analysis (DIVA) mapping method. Improving on maps based on an earlier but similar dataset, GLODAPv1.1, this climatology also covers the Arctic Ocean. Climatologies were created for 33 standard depth surfaces. The conceivably confounding temporal trends in TCO2 and pH due to anthropogenic influence were removed prior to mapping by normalizing these data to the year 2002 using first-order calculations of anthropogenic carbon accumulation rates. We additionally provide maps of accumulated anthropogenic carbon in the year 2002 and of preindustrial TCO2. For all parameters, all data from the full 1972-2013 period were used, including data that did not receive full secondary quality control. The GLODAPv2.2016b global 1° × 1° mapped climatologies, including error fields and ancillary information, are available at the GLODAPv2 web page at the Carbon Dioxide Information Analysis Center (CDIAC; http://dx.doi.org/10.3334/CDIAC/OTG.NDP093_GLODAPv2" target="_blank">doi:10.3334/CDIAC/OTG.NDP093_GLODAPv2).

  6. Quantifying uncertainty in climatological fields from GPS radio occultation: an empirical-analytical error model

    Directory of Open Access Journals (Sweden)

    B. Scherllin-Pirscher

    2011-05-01

    Full Text Available Due to the measurement principle of the radio occultation (RO technique, RO data are highly suitable for climate studies. Single RO profiles can be used to build climatological fields of different atmospheric parameters like bending angle, refractivity, density, pressure, geopotential height, and temperature. RO climatologies are affected by random (statistical errors, sampling errors, and systematic errors, yielding a total climatological error. Based on empirical error estimates, we provide a simple analytical error model for these error components, which accounts for vertical, latitudinal, and seasonal variations. The vertical structure of each error component is modeled constant around the tropopause region. Above this region the error increases exponentially, below the increase follows an inverse height power-law. The statistical error strongly depends on the number of measurements. It is found to be the smallest error component for monthly mean 10° zonal mean climatologies with more than 600 measurements per bin. Due to smallest atmospheric variability, the sampling error is found to be smallest at low latitudes equatorwards of 40°. Beyond 40°, this error increases roughly linearly, with a stronger increase in hemispheric winter than in hemispheric summer. The sampling error model accounts for this hemispheric asymmetry. However, we recommend to subtract the sampling error when using RO climatologies for climate research since the residual sampling error remaining after such subtraction is estimated to be 50 % of the sampling error for bending angle and 30 % or less for the other atmospheric parameters. The systematic error accounts for potential residual biases in the measurements as well as in the retrieval process and generally dominates the total climatological error. Overall the total error in monthly means is estimated to be smaller than 0.07 % in refractivity and 0.15 K in temperature at low to mid latitudes, increasing towards

  7. Aerosol climatology using a tunable spectral variability cloud screening of AERONET data

    Science.gov (United States)

    Kaufman, Yoram J.; Gobbi, Gian Paolo; Koren, Ilan

    2005-01-01

    Can cloud screening of an aerosol data set, affect the aerosol optical thickness (AOT) climatology? Aerosols, humidity and clouds are correlated. Therefore, rigorous cloud screening can systematically bias towards less cloudy conditions, underestimating the average AOT. Here, using AERONET data we show that systematic rejection of variable atmospheric optical conditions can generate such bias in the average AOT. Therefore we recommend (1) to introduce more powerful spectral variability cloud screening and (2) to change the philosophy behind present aerosol climatologies: Instead of systematically rejecting all cloud contaminations, we suggest to intentionally allow the presence of cloud contamination, estimate the statistical impact of the contamination and correct for it. The analysis, applied to 10 AERONET stations with approx. 4 years of data, shows almost no change for Rome (Italy), but up to a change in AOT of 0.12 in Beijing (PRC). Similar technique may be explored for satellite analysis, e.g. MODIS.

  8. Quality Control of ARGO Data Based on Climatological T-S Models

    Institute of Scientific and Technical Information of China (English)

    纪风颖; 林绍花

    2004-01-01

    By implementing the ARGO program, a large number of T-S profiles can be observed in the world ocean. However, it is very difficult to examine changes of the sensitivity of the sensors equipped at the ARGO floats, because it is difficult to understand their condition in the sea and the reliability of the data. Quality control must be done in order to avoid the wrong conclusion deduced from the wrong data.One of the realistic methods for quality control of the ARGO data is the comparison with the local climatology. High quality climatological T-S models in northwest Pacific have been built based on the Nansen bottle data and CTD data for the quality control in NMDIS. The models are used to check the ARGO data in this area and have got good result.

  9. The International Satellite Cloud Climatology Project (ISCCP) - The first project of the World Climate Research Programme

    Science.gov (United States)

    Schiffer, R. A.; Rossow, W. B.

    1983-01-01

    The first project of the World Climate Research Program is the International Satellite Cloud Climatology Project, (ISCCP) whose objective is the collection and analysis of satellite radiance data in order to infer the global distribution of cloud radiative properties and improve the modeling of cloud effects on climate. The operational component of ISCCP takes advantage of the global coverage provided by the current and planned international array of geostationary and polar-orbiting meteorological satellites in the 1980s. It will produce a five-year global radiance and cloud data set. The research component of ISCCP will coordinate studies to validate climatology, improve cloud analysis algorithms, improve cloud effects modelling, and investigate the role of clouds in the atmospheric radiation budget and hydrologic cycle.

  10. Flight summaries and temperature climatology at airliner cruise altitudes from GASP (Global Atmospheric Sampling Program) data

    Science.gov (United States)

    Nastrom, G. D.; Jasperson, W. H.

    1983-01-01

    Temperature data obtained by the Global Atmospheric Sampling Program (GASP) during the period March 1975 to July 1979 are compiled to form flight summaries of static air temperature and a geographic temperature climatology. The flight summaries include the height and location of the coldest observed temperature and the mean flight level, temperature and the standard deviation of temperature for each flight as well as for flight segments. These summaries are ordered by route and month. The temperature climatology was computed for all statistically independent temperture data for each flight. The grid used consists of 5 deg latitude, 30 deg longitude and 2000 feet vertical resolution from FL270 to FL430 for each month of the year. The number of statistically independent observations, their mean, standard deviation and the empirical 98, 50, 16, 2 and .3 probability percentiles are presented.

  11. Polar low climatology over the Nordic and Barents seas based on satellite passive microwave data

    Science.gov (United States)

    Smirnova, Julia E.; Golubkin, Pavel A.; Bobylev, Leonid P.; Zabolotskikh, Elizaveta V.; Chapron, Bertrand

    2015-07-01

    A new climatology of polar lows over the Nordic and Barents seas for 14 seasons (1995/1996-2008/2009) is presented. For the first time in climatological studies of polar lows an approach based on satellite passive microwave data was adopted for polar low identification. A total of 637 polar lows were found in 14 extended winter seasons by combining total atmospheric water vapor content and sea surface wind speed fields retrieved from Special Sensor Microwave/Imager data. As derived, the polar low activity in the Norwegian and Barents Seas is found to be almost equal, and the main polar low genesis area is located northeastward of the North Cape. For the Barents Sea, a significant correlation is found between the number of polar lows and mean sea ice extent. Individual indicative polar low characteristics (i.e., diameter, lifetime, distance traveled, translation speed, and maximum wind speed) are also presented.

  12. An Update to the Warm-Season Convective Wind Climatology of KSC/CCAFS

    Science.gov (United States)

    Lupo, Kevin

    2012-01-01

    Total of 1100 convective events in the 17-year warm-season climatology at KSC/CCAFS. July and August typically are the peak of convective events, May being the minimum. Warning and non-warning level convective winds are more likely to occur in the late afternoon (1900-2000Z). Southwesterly flow regimes and wind directions produce the strongest winds. Storms moving from southwesterly direction tend to produce more warning level winds than those moving from the northerly and easterly directions.

  13. An Updated TRMM Composite Climatology of Tropical Rainfall and Its Validation

    Science.gov (United States)

    Wang, Jian-Jian; Adler, Robert F.; Huffman, George; Bolvin, David

    2013-01-01

    An updated 15-yr Tropical Rainfall Measuring Mission (TRMM) composite climatology (TCC) is presented and evaluated. This climatology is based on a combination of individual rainfall estimates made with data from the primaryTRMMinstruments: theTRMM Microwave Imager (TMI) and the precipitation radar (PR). This combination climatology of passive microwave retrievals, radar-based retrievals, and an algorithm using both instruments simultaneously provides a consensus TRMM-based estimate of mean precipitation. The dispersion of the three estimates, as indicated by the standard deviation sigma among the estimates, is presented as a measure of confidence in the final estimate and as an estimate of the uncertainty thereof. The procedures utilized by the compositing technique, including adjustments and quality-control measures, are described. The results give a mean value of the TCC of 4.3mm day(exp -1) for the deep tropical ocean beltbetween 10 deg N and 10 deg S, with lower values outside that band. In general, the TCC values confirm ocean estimates from the Global Precipitation Climatology Project (GPCP) analysis, which is based on passive microwave results adjusted for sampling by infrared-based estimates. The pattern of uncertainty estimates shown by sigma is seen to be useful to indicate variations in confidence. Examples include differences between the eastern and western portions of the Pacific Ocean and high values in coastal and mountainous areas. Comparison of the TCC values (and the input products) to gauge analyses over land indicates the value of the radar-based estimates (small biases) and the limitations of the passive microwave algorithm (relatively large biases). Comparison with surface gauge information from western Pacific Ocean atolls shows a negative bias (16%) for all the TRMM products, although the representativeness of the atoll gauges of open-ocean rainfall is still in question.

  14. Large-scale processes in the upper layers of the Indian Ocean inferred from temperature climatology

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; PrasannaKumar, S.; Navelkar, G.S.

    (Prasanna Kumar and Unnikrishnan, 1995). 1. Introduction One of the characteristic features of the Indian Ocean north of 20s is the variability associated with the monsoonal wind reversals. Studies on the Indian Ocean dynamics and large-scale processes..., 93-l 15, 1997 Large-scale processes in the upper layers of the Indian Ocean inferred from temperature climatology by A. S. Unnikrishnanl, S. Prasanna Kumarl and G. S. Navelkarl ABSTRACT Determination of amplitudes and phases for the annual...

  15. Metrological challenges for measurements of key climatological observables, Part 4: Atmospheric relative humidity

    OpenAIRE

    Lovell-Smith, J W; Feistel, R; Harvey, A H; Hellmuth, O.; Bell, S A; Heinonen, M.; Cooper, J R

    2016-01-01

    Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest “greenhouse” gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. In this paper, we examine the climatologically relevant atmospheric relative humidity, noting fundamental deficiencies in the definition of this key observable. The met...

  16. A global tropospheric ozone climatology from trajectory-mapped ozone soundings

    OpenAIRE

    Liu, G; Liu, J. J.; Tarasick, D. W.; Fioletov, V. E.; J. J. Jin; O. Moeni; Liu, X.; C. E. Sioris

    2013-01-01

    A global three-dimensional (i.e. latitude, longitude, altitude) climatology of tropospheric ozone is derived from the ozone sounding record by trajectory mapping. Approximately 52 000 ozonesonde profiles from more than 100 stations worldwide since 1962 are used. The small number of stations causes the set of ozone soundings to be sparse in geographical spacing. Here, forward and backward trajectory calculations are performed for each sounding to map ozone measurements to a number of other loc...

  17. A global tropospheric ozone climatology from trajectory-mapped ozone soundings

    Directory of Open Access Journals (Sweden)

    G. Liu

    2013-05-01

    Full Text Available A global three-dimensional (i.e. latitude, longitude, altitude climatology of tropospheric ozone is derived from the ozone sounding record by trajectory mapping. Approximately 52 000 ozonesonde profiles from more than 100 stations worldwide since 1962 are used. The small number of stations causes the set of ozone soundings to be sparse in geographical spacing. Here, forward and backward trajectory calculations are performed for each sounding to map ozone measurements to a number of other locations, and so to fill in the spatial domain. This is possible because the lifetime of ozone in the troposphere is of the order of weeks. This physically-based interpolation method offers obvious advantages over typical statistical interpolation methods. The trajectory-mapped ozone values show reasonable agreement, where they overlap, to the actual soundings, and the patterns produced separately by forward and backward trajectory calculations are similar. Major regional features of the tropospheric ozone distribution are clearly evident in the global maps. An interpolation algorithm based on spherical functions is further used for smoothing and to fill in remaining data gaps. The resulting three-dimensional global tropospheric ozone climatology facilitates visualization and comparison of different years, decades, and seasons, and offers some intriguing insights into the global variation of tropospheric ozone. It will be useful for climate and air quality model initialization and validation, and as an a priori climatology for satellite data retrievals. Further division of the climatology into decadal averages provides a global view of tropospheric ozone trends, which appear to be surprisingly modest over the last four decades.

  18. A global tropospheric ozone climatology from trajectory-mapped ozone soundings

    Science.gov (United States)

    Liu, G.; Liu, J.; Tarasick, D. W.; Fioletov, V. E.; Jin, J. J.; Moeini, O.; Liu, X.; Sioris, C. E.; Osman, M.

    2013-11-01

    A global three-dimensional (i.e. latitude, longitude, altitude) climatology of tropospheric ozone is derived from the ozone sounding record by trajectory mapping. Approximately 52 000 ozonesonde profiles from more than 100 stations worldwide since 1965 are used. The small number of stations results in a sparse geographical distribution. Here, forward and backward trajectory calculations are performed for each sounding to map ozone measurements to a number of other locations, and so to fill in the spatial domain. This is possible because the lifetime of ozone in the troposphere is of the order of weeks. This physically based interpolation method offers obvious advantages over typical statistical interpolation methods. The trajectory-mapped ozone values show reasonable agreement, where they overlap, to the actual soundings, and the patterns produced separately by forward and backward trajectory calculations are similar. Major regional features of the tropospheric ozone distribution are clearly evident in the global maps. An interpolation algorithm based on spherical functions is further used for smoothing and to fill in remaining data gaps. The resulting three-dimensional global tropospheric ozone climatology facilitates visualization and comparison of different years, decades, and seasons, and offers some intriguing insights into the global variation of tropospheric ozone. It will be useful for climate and air quality model initialization and validation, and as an a priori climatology for satellite data retrievals. Further division of the climatology into decadal and annual averages can provide a global view of tropospheric ozone changes, although uncertainties with regard to the performance of older sonde types, as well as more recent variations in operating procedures, need to be taken into account.

  19. A global tropospheric ozone climatology from trajectory-mapped ozone soundings

    OpenAIRE

    Liu, G; Liu, J; Tarasick, D. W.; Fioletov, V. E.; J. J. Jin; Moeini, O.; Liu, X.; C. E. Sioris; Osman, M

    2013-01-01

    A global three-dimensional (i.e. latitude, longitude, altitude) climatology of tropospheric ozone is derived from the ozone sounding record by trajectory mapping. Approximately 52 000 ozonesonde profiles from more than 100 stations worldwide since 1965 are used. The small number of stations results in a sparse geographical distribution. Here, forward and backward trajectory calculations are performed for each sounding to map ozone measurements to a number of other locations,...

  20. Comparison of high-latitude thermospheric meridionalwinds II: combined FPI, radar and model Climatologies

    Directory of Open Access Journals (Sweden)

    E. M. Griffin

    2004-03-01

    Full Text Available The climatological behaviour of the thermospheric meridional wind above Kiruna, Sweden (67.4°N, 20.4°E has been investigated for seasonal and solar cycle dependence using six different techniques, comprising both model and experimental sources. Model output from both the empirical Horizontal Wind Model (HWM (Hedin et al., 1988 and the numerical Coupled Thermosphere and Ionosphere Model (CTIM are compared to the measured behaviour at Kiruna, as a single site example. The empirical International Reference Ionosphere (IRI model is used as input to an implementation of servo theory, to provide another climatology combining empirical input with a theoretical framework. The experimental techniques have been introduced in a companion paper in this issue and provide climatologies from direct measurements, using Fabry-Perot Interferometers (FPI, together with 2 separate techniques applied to the European Incoherent Scatter radar (EISCAT database to derive neutral winds. One of these techniques uses the same implementation of servo theory as has been used with the IRI model. Detailed comparisons for each season and solar activity category allow for conclusions to be drawn as to the major influences on the climatological behaviour of the wind at this latitude. Comparison of the incoherent scatter radar (ISR derived neutral winds with FPI, empirical model and numerical model winds is important to our understanding and judgement of the validity of the techniques used to derive thermospheric wind databases. The comparisons also test model performance and indicate possible reasons for differences found between the models. In turn, the conclusions point to possible improvements in their formulation. In particular it is found that the empirical models are over-reliant on mid-latitude data in their formulation, and fail to provide accurate estimates of the winds at high-latitudes.

    Key words. Meteorology and atmospheric dynamics (thermospheric dynamics

  1. Jet characterization in the upper troposphere/lower stratosphere (UTLS): applications to climatology and transport studies

    OpenAIRE

    Manney, G. L.; Hegglin, M. I.; W. H. Daffer; M. L. Santee; E. A. Ray; Pawson, S.; M. J. Schwartz; C. D. Boone; Froidevaux, L.; N. J. Livesey; W. G. Read; K. A. Walker

    2011-01-01

    A method of classifying the upper tropospheric/lower stratospheric (UTLS) jets has been developed that allows satellite and aircraft trace gas data and meteorological fields to be efficiently mapped in a jet coordinate view. A detailed characterization of multiple tropopauses accompanies the jet characterization. Jet climatologies show the well-known high altitude subtropical and lower altitude polar jets in the upper troposphere, as well as a pattern of concentric polar and subtropical jets ...

  2. Bimodal character of cyclone climatology in the Bay of Bengal modulated by monsoon seasonal cycle

    Digital Repository Service at National Institute of Oceanography (India)

    Li, Z.; Yu, W.; Li, T.; Murty, V.S.N.; Fredolin, T.

    (WSP). TCs draw intense scientific and social interest concerns due to the following three reasons. Firstly, they contribute importantly to the overall summer season rainfall in regions such as WNP. Secondly they play a key role in modulating...., vol.26; 2013; 1033–1046 Bimodal character of cyclone climatology in Bay of Bengal modulated by monsoon seasonal cycle Zhi Li1, Weidong Yu1, Tim Li2, VSN Murty3 and Fredolin Tangang4 1. Center for Ocean and Climate Research, First Institute...

  3. Lower-tropospheric humidity: climatology, trends and the relation to the ITCZ

    OpenAIRE

    Läderach, Alexander; Raible, Christoph C.

    2013-01-01

    The tropical region is an area of maximum humidity and serves as the major humidity source of the globe. Among other phenomena, it is governed by the so-called Inter-Tropical Convergence Zone (ITCZ) which is commonly defined by converging low-level winds or enhanced precipitation. Given its importance as a humidity source, we investigate the humidity fields in the tropics in different reanalysis data sets, deduce the climatology and variability and assess the relationship to the ITCZ. Therefo...

  4. Sound speed in the Mediterranean Sea: an analysis from a climatological data set

    OpenAIRE

    S. Salon; A. Crise; P. Picco; Marinis, E; O. Gasparini

    2003-01-01

    This paper presents an analysis of sound speed distribution in the Mediterranean Sea based on climatological temperature and salinity data. In the upper layers, propagation is characterised by upward refraction in winter and an acoustic channel in summer. The seasonal cycle of the Mediterranean and the presence of gyres and fronts create a wide range of spatial and temporal variabilities, with relevant differences between the western and eastern basins. It is shown tha...

  5. A Global Climatology of Tropospheric and Stratospheric Ozone Derived from Aura OMI and MLS Measurements

    Science.gov (United States)

    Ziemke, J.R.; Chandra, S.; Labow, G.; Bhartia, P. K.; Froidevaux, L.; Witte, J. C.

    2011-01-01

    A global climatology of tropospheric and stratospheric column ozone is derived by combining six years of Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone measurements for the period October 2004 through December 2010. The OMI/MLS tropospheric ozone climatology exhibits large temporal and spatial variability which includes ozone accumulation zones in the tropical south Atlantic year-round and in the subtropical Mediterranean! Asia region in summer months. High levels of tropospheric ozone in the northern hemisphere also persist in mid-latitudes over the eastern North American and Asian continents extending eastward over the Pacific Ocean. For stratospheric ozone climatology from MLS, largest ozone abundance lies in the northern hemisphere in the latitude range 70degN-80degN in February-April and in the southern hemisphere around 40degS-50degS during months August-October. The largest stratospheric ozone abundances in the northern hemisphere lie over North America and eastern Asia extending eastward across the Pacific Ocean and in the southern hemisphere south of Australia extending eastward across the dateline. With the advent of many newly developing 3D chemistry and transport models it is advantageous to have such a dataset for evaluating the performance of the models in relation to dynamical and photochemical processes controlling the ozone distributions in the troposphere and stratosphere.

  6. Characterizing sampling biases in the trace gas climatologies of the SPARC Data Initiative

    Science.gov (United States)

    Toohey, M.; Hegglin, M. I.; Tegtmeier, S.; Anderson, J.; Añel, J. A.; Bourassa, A.; Brohede, S.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A.; Kasai, Y.; Krüger, K.; Kyrölä, E.; Neu, J. L.; Rozanov, A.; Smith, L.; Urban, J.; Clarmann, T.; Walker, K. A.; Wang, R. H. J.

    2013-10-01

    zonal mean climatologies of atmospheric measurements from satellite instruments can have biases due to the nonuniform sampling of the atmosphere by the instruments. We characterize potential sampling biases in stratospheric trace gas climatologies of the Stratospheric Processes and Their Role in Climate (SPARC) Data Initiative using chemical fields from a chemistry climate model simulation and sampling patterns from 16 satellite-borne instruments. The exercise is performed for the long-lived stratospheric trace gases O3 and H2O. Monthly sampling biases for O3 exceed 10% for many instruments in the high-latitude stratosphere and in the upper troposphere/lower stratosphere, while annual mean sampling biases reach values of up to 20% in the same regions for some instruments. Sampling biases for H2O are generally smaller than for O3, although still notable in the upper troposphere/lower stratosphere and Southern Hemisphere high latitudes. The most important mechanism leading to monthly sampling bias is nonuniform temporal sampling, i.e., the fact that for many instruments, monthly means are produced from measurements which span less than the full month in question. Similarly, annual mean sampling biases are well explained by nonuniformity in the month-to-month sampling by different instruments. Nonuniform sampling in latitude and longitude are shown to also lead to nonnegligible sampling biases, which are most relevant for climatologies which are otherwise free of biases due to nonuniform temporal sampling.

  7. Meteorology and Climatology education: an Experience with young people in Friuli Venezia Giulia - Italy

    Science.gov (United States)

    Nordio, S.; Pucillo, A.; Micheletti, S.

    2010-09-01

    We propose, as a poster, the experience in meteorology and climatology education that has been acquired by OSMER ARPA FVG (the local regional meteorological observatory of the Friuli Venezia Giulia region, NE Italy). It was aimed at spreading a better culture in meteorology, climatology and environmental-friendly behaviour through general and specific knowledge. In the last 10 years many public and private schools were involved into a net of knowledge through the work of a pool of teachers, proposing a new way of understanding meteorology studies. The first step was to catch the attention of students on the observation tools, in particular on the meteorological ground-based instruments: a wooden-made box has been built to host meteorological instruments. The second step was to teach the main methods to collect correct observations and to simply analyze meteorological data. In a following step we propose to a small group of highschool students to carry on their knowledge in meteorology and climatology for younger students through the exhibit of 20 kits containing meteorological instruments and various experiments in environmental sector (energy saving, greenhouse effect, etc), according to the method of peer-education, during special meetings with the participation of hundreds young students. The last step has been the interpretation of the new knowledge acquired by the young students through the realization of banners, videoclip, website, etc.

  8. Training programme for the dissemination of climatological and meteorological applications using GIS technology

    Directory of Open Access Journals (Sweden)

    T. De Filippis

    2006-01-01

    Full Text Available IBIMET-CNR is involved in making different research projects and in managing operational programmes on national and international level and has acquired a relevant training competence to sustain partner countries and improve their methodological and operational skills by using innovative tools, such as Geographical Information Systems focused on the development of meteorological and climatological applications. Training activities are mainly addressed to National Meteorological and Hydrological Services of Partner-Countries and/or to other Specialized Centers in the frame of Cooperation Programmes promoted by the Italian Ministry of Foreign Affairs mainly in favour of the Less Developing Countries (LDC of World Meteorological Organisation (WMO Regional Association I (Africa. The Institute, as a branch of the WMO-Regional Meteorological Training Centre for Region VI (Europe, organizes also international training courses of high-level in Meteorology, Climatology and Remote Sensing applied to environment and agriculture fields. Moreover, considering the increasing evolution of the GIS functions for meteorological information users, IBIMET has promoted in 2005 the EU COST Action 719 Summer School on "GIS applications in meteorology and climatology''. The paper offers an overview of the main institute training programmes organised to share the results of research activities and operational projects, through the exploitation of innovative technologies and tools like GIS.

  9. Sound speed in the Mediterranean Sea: an analysis from a climatological data set

    Directory of Open Access Journals (Sweden)

    S. Salon

    Full Text Available This paper presents an analysis of sound speed distribution in the Mediterranean Sea based on climatological temperature and salinity data. In the upper layers, propagation is characterised by upward refraction in winter and an acoustic channel in summer. The seasonal cycle of the Mediterranean and the presence of gyres and fronts create a wide range of spatial and temporal variabilities, with relevant differences between the western and eastern basins. It is shown that the analysis of a climatological data set can help in defining regions suitable for successful monitoring by means of acoustic tomography. Empirical Orthogonal Functions (EOF decomposition on the profiles, performed on the seasonal cycle for some selected areas, demonstrates that two modes account for more than 98% of the variability of the climatological distribution. Reduced order EOF analysis is able to correctly represent sound speed profiles within each zone, thus providing the a priori knowledge for Matched Field Tomography. It is also demonstrated that salinity can affect the tomographic inversion, creating a higher degree of complexity than in the open oceans.

    Key words. Oceanography: general (marginal and semi-enclosed seas; ocean acoustics

  10. On the derivation of spatially highly resolved precipitation climatologies under consideration of radar-derived precipitation rates

    OpenAIRE

    Kronenberg, Rico

    2015-01-01

    In this cumulative dissertation, different features and methods are presented to assess and process multi-sensor derived radar data for climatological analysis. The overall objectives were to appraise the limitations of an hourly radar-based quantitative precipitation estimate (QPE) product and to develop and apply reasonable approaches to process these data. Hence the spatial and temporal limitations of radar-derived precipitation rates are discussed in the context of climatological applicat...

  11. Joint statistical correction of clutters, spokes and beam height for a radar derived precipitation climatology in southern Germany

    OpenAIRE

    Wagner, A; Seltmann, J.; Kunstmann, H.

    2012-01-01

    First results of radar derived climatology have emerged over the last years, as datasets of appropriate extent are becoming available. Usually, these statistics are based on time series lasting up to ten years as continuous storage of radar data was often not achieved before. This kind of climatology demands a high level of data quality. Small deviations or minor systematic under- or overestimations in single radar images become a major cause of error in statistical analysis. Extensive correc...

  12. Evaluation of spatio-temporal variability of Hamburg Aerosol Climatology against aerosol datasets from MODIS and CALIOP

    OpenAIRE

    V. Pappas; N. Hatzianastassiou; C. Papadimas; Matsoukas, C.; Kinne, S.; Vardavas, I.

    2013-01-01

    The new global aerosol climatology named HAC (Hamburg Aerosol Climatology) is compared against MODIS (MODerate resolution Imaging Spectroradiometer, Collection 5, 2000–2007) and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization, Level 2-Version 3, 2006–2011) retrievals. The HAC aerosol optical depth (AOD) values are larger than MODIS in heavy aerosol load conditions (over land) and lower over oceans. Agreement between HAC and MODIS is better over land and for low AOD. Hemispherica...

  13. Dynamic Adjustment of Climatological Ozone Boundary Conditions for Air-Quality Forecasts

    Directory of Open Access Journals (Sweden)

    P. A. Makar

    2010-06-01

    Full Text Available Ten different approaches for applying lateral and top climatological boundary conditions for ozone have been evaluated using the off-line regional air-quality model AURAMS. All ten approaches employ the same climatological ozone profiles, but differ in the manner in which they are applied, via the inclusion or exclusion of (i a dynamic adjustment of the climatological ozone profile in response to the model-predicted tropopause height, (ii a sponge zone for ozone on the model top, (iii upward extrapolation of the climatological ozone profile, and (iv different mass consistency corrections. The model performance for each approach was evaluated against North American surface ozone and ozonesonde observations from the BAQS-Met field study period in the summer of 2007. The original daily one-hour maximum surface ozone biases of about +15 ppbv were greatly reduced (halved in some simulations using alternative methodologies. However, comparisons to ozonesonde observations showed that the reduction in surface ozone bias sometimes came at the cost of significant positive biases in ozone concentrations in the free troposphere and upper troposphere. The best overall performance throughout the troposphere was achieved using a methodology that included dynamic tropopause height adjustment, no sponge zone at the model top, extrapolation of ozone when required above the limit of the climatology, and no mass consistency corrections (global mass conservation was still enforced. The simulation using this model version had a one-hour daily maximum surface ozone bias of +8.6 ppbv, with small reductions in model correlation, and the best comparison to ozonesonde profiles. This recommended and original methodologies were compared for two further case studies: a high-resolution simulation of the BAQS-Met measurement intensive, and a study of the downwind region of the Canadian Rockies. Significant improvements were noted for the high resolution simulations during the

  14. A 14-Year TRMM Composite Climatology of Tropical Rainfall with Version 7 Data

    Science.gov (United States)

    Wang, J.; Adler, R. F.; Huffman, G. J.; Gu, G.

    2012-12-01

    The first-time use of both active and passive microwave instruments onboard the Tropical Rainfall Measuring Mission (TRMM, launched in late 1997) has made TRMM the foremost satellite for the study of precipitation in the tropics. One of the key goals of TRMM has been to define the spatial and seasonal climatological rainfall in the tropics as accurately as possible in order to quantify this key component of the hydrological cycle. A climatology of tropical surface rain has been developed based on a composite of fourteen years (1998-2011) of precipitation products from recent TRMM Version 7 (V7) data (Adler et al. 2009, JMSJ). The TRMM Composite Climatology (TCC) V7 consists of a merger of selected TRMM rainfall products over both land and ocean to give a "TRMM-best" climatological estimate. For this new version of the TCC (using TRMM V7 inputs) there have been some changes in the input data sets and in the methods. For the previous TCC V6 product, over ocean, the TCC inputs included the passive microwave retrieval using data from the TRMM Microwave Imager (TMI), the active microwave retrieval using data from the Precipitation Radar (PR), and the combined TMI-PR product, a separate retrieval with different assumptions. Over land, the TMI V6 estimates are known to overestimate surface rainfall, especially in the warm season. Therefore, the TRMM Multi-satellite Precipitation Analysis (TMPA) was used to replace the TMI. However, from our recent analysis of the TRMM products, it is found that TMI V7 rainfall estimates over land have significantly smaller biases and have much better agreement with the PR and the combined TMI-PR products, except in some mountainous regions due to the problematic rainfall screening processes. Therefore, we decided to include the TMI V7 estimates instead of TMPA as one of the components in the TCC V7 over land using some quality control techniques. Consequently, the new version of the TCC becomes a TRMM satellite only rainfall climatology

  15. Tropopause referenced ozone climatology and inter-annual variability (1994–2003 from the MOZAIC programme

    Directory of Open Access Journals (Sweden)

    Thouret

    2006-01-01

    Full Text Available The MOZAIC programme collects ozone and water vapour data using automatic equipment installed on board five long-range Airbus A340 aircraft flying regularly all over the world since August 1994. Those measurements made between September 1994 and August 1996 allowed the first accurate ozone climatology at 9–12 km altitude to be generated. The seasonal variability of the tropopause height has always provided a problem when constructing climatologies in this region. To remove any signal from the seasonal and synoptic scale variability in tropopause height we have chosen in this further study of these and subsequent data to reference our climatology to the altitude of the tropopause. We define the tropopause as a mixing zone 30 hPa thick across the 2 pvu potential vorticity surface. A new ozone climatology is now available for levels characteristic of the upper troposphere (UT and the lower stratosphere (LS regardless of the seasonal variations of the tropopause over the period 1994–2003. Moreover, this new presentation has allowed an estimation of the monthly mean climatological ozone concentration at the tropopause showing a sine seasonal variation with a maximum in May (120 ppbv and a minimum in November (65 ppbv. Besides, we present a first assessment of the inter-annual variability of ozone in this particular critical region. The overall increase in the UTLS is about 1%/yr for the 9 years sampled. However, enhanced concentrations about 10–15 % higher than the other years were recorded in 1998 and 1999 in both the UT and the LS. This so-called '1998–1999 anomaly' may be attributed to a combination of different processes involving large scale modes of atmospheric variability, circulation features and local or global pollution, but the most dominant one seems to involve the variability of the North Atlantic Oscillation (NAO as we find a strong positive correlation (above 0.60 between ozone recorded in the upper troposphere and the NAO

  16. Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer dataset

    Directory of Open Access Journals (Sweden)

    A. Jones

    2011-11-01

    Full Text Available The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS aboard the Canadian satellite SCISAT (launched in August 2003 was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC Chemistry Climate Model validation activity. The ACE-FTS climatological dataset is available through the ACE website.

  17. Climatology and trends of summer high temperature days in India during 1969–2013

    Indian Academy of Sciences (India)

    A K Jaswal; P C S Rao; Virendra Singh

    2015-02-01

    Based on the daily maximum air temperature data from 176 stations in India from 1969 to 2013, the climatological distribution of the number of days with high temperature (HT) defined as days with maximum temperature higher than 37°C during summer season (March–June) are studied. With a focus on the regional variability and long-term trends, the impacts of HT days are examined by dividing the country into six geographical regions (North, West, North-central, East, South-central and South). Although the long-term (1969–2013) climatological numbers of HT days display well-defined spatial patterns, there is clear change in climatological mean and coefficient of variation of HT days in a recent period (1991–2013). The long period trends indicate increase in summer HT days by 3%, 5%, and 18% in north, west, and south regions, respectively and decrease by 4% and 9% in north-central and east regions respectively. However, spatial variations in HT days exist across different regions in the country. The data analysis shows that 2010 was the warmest summer year and 2013 was the coolest summer year in India. Comparison of spatial distributions of trends in HT days for 1969–1990 and 1991–2013 periods reveal that there is an abrupt increase in the number of HT days over north, west and north-central regions of India probably from mid 1990s. A steep increase in summer HT days in highly populated cities of Mumbai, New Delhi, Chennai, Jaipur, and Visakhapatnam is noticed during the recent period of 1991–2013. The summer HT days over southern India indicate significant positive correlation with Nino 3.4 index for three months’ running mean (December–January–February, January–March, February–April, March–May and April–June).

  18. Monthly Climatology of Thermospheric Zonal and Meridional Winds Obtained from a Kalman Filter Model

    Science.gov (United States)

    Scherliess, L.; Lomidze, L.

    2015-12-01

    Knowledge of the thermospheric neutral wind and its meridional and zonal components is critical for an improved understanding of the low- and mid-latitude F-region dynamics and morphology. To date, the reliable estimation of the wind and its components remains a challenge because of difficulties in both measurement and modeling. Previous methods that use ionospheric measurements to deduce winds provide their values only in the direction of the magnetic meridian. We will present the monthly climatology of the zonal and meridional components of thermospheric neutral wind at low and mid-latitudes obtained by a Kalman Filter technique. First, the climatology of the magnetic meridional wind is obtained by assimilating monthly maps of F-region ionosphere peak parameters (NmF2 and hmF2), obtained from COSMIC radio occultation data, into the Global Assimilation of Ionospheric Measurements Full Physics (GAIM-FP) model. The model provides the 3-D electron density throughout the ionosphere, together with the magnetic meridional wind. Next, the estimation of the global zonal and meridional wind components is performed using the newly developed Thermospheric Wind Assimilation Model (TWAM). TWAM combines magnetic meridional wind data obtained from GAIM-FP with a physics-based 3-D thermospheric neutral wind model using an implicit Kalman Filter technique. The ionospheric drag and ion diffusion velocities, needed for the wind calculation, are also taken from the GAIM-FP model. We present the monthly climatology of our wind estimation and compare individual horizontal wind components to their corresponding empirical model values and to measurements made by interferometers.

  19. Statistical analysis of five yearly (1997-2001) diffusion climatology of Trombay

    International Nuclear Information System (INIS)

    This report summarizes the analysis of meteorological data collected at Trombay Bhabha Atomic Research Centre. d1,1ring the period 1997-2001. The data include wind speed wind direction. insolation (incoming solar radiation). air temperature. relative humidity and rainfall. Diffusion climatological pattern and general climatological trends at the site observed over the report periud are examined. Extreme values of various parameters observed over the five-year period are also reported. As an application of the diffusion climatological analysis, the report presents the computed values of: (i) The annual average normalized meteorological dilution factor i.e.. downwind ground level concentration of a radionuclide per unit release rate (Bq m-3/Bq S-1 or s m-3) at radial distances of 1.6 km and 2.3 km. The computations are carried out for the 16 wind direction sectors using 100 m release height. The sector weighted average values are also presented. (ii) The normalized annual 41Ar plume gamma dose per unit release rate (μSv/Bq S-1) in each sector and the sector weighted average value at 1.6 km and 2.3 km radial distances. (iii) The annual gamma doses at the Main Gate. South site and North Gate due to the combined release of 41Ar from the CIRUS and DHRUVA reactor stacks. The report also summarizes the results of comparison of meteorological data obtained from the recently installed SODAR system with those obtained from the conventional system for a typical period. (author)

  20. Constraining the climatology of CO2 ocean surface flux for North Atlantic and the Arctic

    Science.gov (United States)

    Wróbel, Iwona; Piskozub, Jacek

    2015-04-01

    The ocean sink is an important part of the anthropogenic CO2 budget. Because the terrestrial biosphere is usually treated as a residual, constraining the net flux into the ocean sink is crucial for understanding the global carbon cycle. The air-sea interface flux is calculated from millions of measurements of CO2 partial pressures. However the regional and temporal means depend on parametrization of gas transfer velocity as well as on the wind/waves fields used for calculations. A recently developed tool, FluxEngine, created within the ESA funded (SOLAS related) OceanFlux Greenhouse Gases project, creates an opportunity to create an ensemble of regional CO2 flux climatologies for the North Atlantic and Arctic waters using multiple combinations of forcing fields and gas transfer velocity parameterizations. The aim of the study is to provide constraints on the regional monthly averages for the chosen area for the whole "climatology ensemble". This approach is similar to the one used by IPCC for the whole model ensemble used for modeling of the climate. Doing a regional study provides an additional test of the parameterizations because the local flux averages may differ even for parameterizations giving similar global averages. We present the methodology and CO2 flux climatology constrains for selected regions and seasons, the preliminary results of a study which aim is to cover the whole North Atlantic and ice-free areas of Arctic Ocean. The study is done within the new ESA funded OceanFlux Evolution project we are part of and at the same time is part of a PhD thesis funded by Centre of Polar Studies "POLAR-KNOW" (a project of the Polish Ministry of Science).

  1. The Hamburg Ocean-Atmosphere Parameters and Fluxes from Satellite Data (HOAPS): A climatological atlas of satellite-derived air-sea interaction parameters over the world oceans

    Digital Repository Service at National Institute of Oceanography (India)

    Grassl, H.; Jost, V.; Schulz, J.; RameshKumar, M.R.; Bauer, P.; Schluessel, P.

    climatological data base for scientists and students in the field of climatology, me- teorology, oceanography, and air-sea interaction. The document describes the various satellite sensors used and details the method by which the fluxes are derived from those.... The present climatology is subdivided in three parts: basic state variables, energy fluxes, and water balance components. It consists of global fields of sea surface temperature, saturation specific humidity at sea sur- face temperature, specific air humidity...

  2. A climatology of the diurnal variations of stratospheric and mesospheric ozone over Bern, Switzerland

    OpenAIRE

    Studer, Simone; Hocke, Klemens; Schanz, Ansgar Ulrich; Schmidt, Hauke; Kämpfer, Niklaus

    2013-01-01

    The ground-based radiometer GROMOS, stationed in Bern (47.95° N, 7.44° E), Switzerland, has a unique dataset: it obtains ozone profiles from November 1994 to present with a time resolution of 30 min and equal quality during night- and daytime. Here, we derive a monthly climatology of the daily ozone cycle from 17 yr of GROMOS observation. We present the diurnal ozone variation of the stratosphere and mesosphere. Characterizing the diurnal cycle of stratospheric ozone is important for correct ...

  3. The SPARC Data Initiative: A comparison of ozone climatologies from international satellite limb sounders

    OpenAIRE

    Tegtmeier, Susann; Hegglin, M. I.; Anderson, J; Bourassa, A.; Brohede, S.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A; Kasai, Y.; Krüger, Kirstin; E. Kyrölä; Lingenfelser, G.

    2013-01-01

    A comprehensive quality assessment of the ozone products from 18 limb-viewing satellite instruments is provided by means of a detailed inter-comparison. The ozone climatologies in the form of monthly zonal mean time series covering the upper troposphere to lower mesosphere are obtained from LIMS, SAGE I, SAGE II, UARS-MLS, HALOE, POAM II, POAM III, SMR, OSIRIS, SAGE III, MIPAS, GOMOS, SCIAMACHY, ACE-FTS, ACE-MAESTRO, Aura-MLS, HIRDLS, and SMILES within 1978-2010. The inter-comparisons focus o...

  4. Statistical examination of climatological data relevant to global temperature variation. Progress report, July 1991--January 1992

    Energy Technology Data Exchange (ETDEWEB)

    Gray, H.L.; Gunst, R.F.; Woodward, W.A.

    1992-01-01

    The research group at Southern Methodist University has been involved in the examination of climatological data as specified in the proposal. Our efforts have resulted in three papers which have been submitted to scholarly journals, as well as several other projects which should be completed either during the next six months or next year. In the following, we discuss our results to date along with projected progress within the next six months. Major topics discussed in this progress report include: testing for trend in the global temperature data; (2) defining and estimating mean global temperature change; and, (3) the effect of initial conditions on autoregressive models for global temperature data.

  5. A global climatology of stratospheric OClO derived from GOMOS measurement

    Directory of Open Access Journals (Sweden)

    C. Tétard

    2013-04-01

    Full Text Available The Global Ozone Monitoring by Occultation of Stars (GOMOS instrument on board the European platform ENVISAT was dedicated to the study of the atmosphere of the Earth using the stellar occultation technique. The spectral range of the GOMOS spectrometer extends from the UV to the near infrared, allowing for the retrieval of species such as O3, NO2, NO3, H2O, O2, air density, aerosol extinction and OClO. Nevertheless, OClO can not be retrieved using a single GOMOS measurement because of the weak signal-to-noise ratio and the small optical thickness associated with this molecule. We present here the method used to detect this molecule by using several GOMOS measurements. It is based on a two-step approach. First, several co-located measurements are combined in a statistical way to build an averaged measurement with a higher signal-to-noise ratio. Then, a Differential Optical Absorption Spectroscopy (DOAS method is applied to retrieve OClO slant column densities. The statistics of the sets of GOMOS measurements used to build the averaged measurement and the spectral window selection are analyzed. The obtained retrievals are compared to results from two balloon-borne instruments. It appears that the inter-comparisons of OClO are generally satisfying. Then, two nighttime climatologies of OClO slant column densities based on GOMOS averaged measurements are presented. The first depicts annual global pictures of OClO from 2003 to 2011. From this climatology, the presence of an OClO layer in the equatorial region at about 35 km is confirmed and strong concentrations of OClO in both polar regions are observed, a sign of chlorine activation. The second climatology is a monthly time series. It clearly shows the chlorine activation of the lower stratosphere during winter. Moreover the equatorial OClO layer is observed during all the years without any significant variations. Finally, the anti-correlation between OClO and NO2 is highlighted. This very promising

  6. The Updated TRMM Composite Climatology of Tropical Rainfall with Version 7 Data

    Science.gov (United States)

    Wang, J.-J.; Adler, R. F.; Huffman, G. J.; Bolvin, D. T.; Gu, G.

    2012-04-01

    The first-time use of both active and passive microwave instruments onboard the Tropical Rainfall Measuring Mission (TRMM, launched in late 1997) has made TRMM the foremost satellite for the study of precipitation in the tropics. One of the key goals of TRMM has been to define the spatial and seasonal climatological rainfall in the tropics as accurately as possible in order to quantify this key component of the hydrological cycle. A climatology of tropical surface rain has been developed based on a composite of thirteen years (1998-2010) of precipitation products from TRMM Version 6 (V6) data (Adler et al. 2009, JMSJ). The TRMM Composite Climatology (TCC) V6 consists of a merger of selected TRMM rainfall products over both land and ocean to give a "TRMM-best" climatological estimate. Over ocean, the TCC inputs include the passive microwave retrieval using data from the TRMM Microwave Imager (TMI), the active microwave retrieval using data from the Precipitation Radar (PR), and the combined TMI-PR product, a separate retrieval with different assumptions. Over land, the TMI V6 estimates are known to overestimate surface rainfall, especially in the warm season. Therefore, the TRMM Multi-satellite Precipitation Analysis (TMPA) was used to replace the TMI . A new version 7 (V7) of the TRMM data was released recently in late 2011. It is our intention to update the current TCC product using the V7 dataset. Our initial analysis of the TCC components indicates that compared to TMI V6, TMI V7 rainfall estimates over land are reduce significantly and have much better agreement with the PR and the combined TMI-PR products. Consequently, we could use the TMI V7 estimates as one of the components in the updated TCC over land, at least as a test. In addition to the mean precipitation estimate, the TCC also includes the variation among the three estimates at each point to give an estimate of the error in the mean value. For evaluation and validation purposes, a series of inter

  7. An updated analysis of the Lucas Heights Climatology - 1975 to 1996

    International Nuclear Information System (INIS)

    Meteorological data collected from 1975 to 1996 in the Lucas Heights region have been summarised to provide an update on the climatology. Initially data were recorded in analogue form but since 1991 advanced digital recording systems have allowed more accurate and extensive statistics to be analysed. Since 1993 a network of meteorological stations has been installed through the surrounding area to investigate the influence of complex terrain on wind flow and atmospheric dispersion patterns. A large data volumes is presented together with some initial interpretation of these complex terrain influences on the Lucas Heights region climatolology

  8. Metrological challenges for measurements of key climatological observables Part 2: oceanic salinity

    Science.gov (United States)

    Pawlowicz, R.; Feistel, R.; McDougall, T. J.; Ridout, P.; Seitz, S.; Wolf, H.

    2016-02-01

    Salinity is a key variable in the modelling and observation of ocean circulation and ocean-atmosphere fluxes of heat and water. In this paper, we examine the climatological relevance of ocean salinity, noting fundamental deficiencies in the definition of this key observable, and its lack of a secure foundation in the International System of Units, the SI. The metrological history of salinity is reviewed, problems with its current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10.

  9. Global climatology of surface water temperatures of large lakes by remote sensing

    OpenAIRE

    Layden, Aisling; Merchant, Christopher; MacCallum, Stuart

    2015-01-01

    Lake surface water temperatures (LSWTs) of 246 globally distributed large lakes were derived from Along-Track Scanning Radiometers (ATSR) for the period 1991–2011. The climatological cycles of mean LSWT derived from these data quantify on a global scale the responses of large lakes' surface temperatures to the annual cycle of forcing by solar radiation and the ambient meteorological conditions. LSWT cycles reflect the twice annual peak in net solar radiation for lakes between 1°S to 12°N. For...

  10. Dynamical Tropopause Variability and Potential Vorticity Streamers in the Northern Hemisphere——A Climatological Analysis

    Institute of Scientific and Technical Information of China (English)

    Olivia MARTIUS; Cornelia SCHWIERZ; Michael SPRENGER

    2008-01-01

    This study presents a 44-year climatology of potential vorticity (PV) streamers in the Northern Hemi sphere based upon analyses of the ERA-40 reanalysis data set. A comparison to an existing 15-year clima tology yields very good agreement in the locations of PV streamer frequency maxima, but some differences are found in the amplitude of frequencies. The climatology is assessed with the focus on links between PV streamer frequencies and the synoptic- and planetary-scale variability of the dynamical tropopause. A comprehensive overview is provided on where (zonally) and when (seasonally) short-term variability throughout the extra-tropical and sub-tropical tropopause is enhanced or reduced. Several key processes that influence this variability are discussed. Baroclinic processes, for example, determine the variability in the storm-track areas in winter, whereas the Asian summer monsoon significantly influences the variability over Asia. The paper also describes links between the frequency of PV streamers in the extra-tropical and sub tropical tropopause and three major northern hemisphere teleconnection patterns. The observed changes in the PV streamer frequencies are closely related to concomitant variations of PV and its gradient within the tropopause region. During opposite phases of the North Atlantic Oscillation the location of the streamer frequency maxima shifts significantly in the Atlantic and European region in both the extra-tropics and subtropics. The influence of ENSO on the streamer frequencies is most pronounced in the subtropical Pacific.

  11. Precipitation Climatology over Mediterranean Basin from Ten Years of TRMM Measurements

    Science.gov (United States)

    Mehta, Amita V.; Yang, Song

    2008-01-01

    Climatological features of mesoscale rain activities over the Mediterranean region between 5 W-40 E and 28 N-48 N are examined using the Tropical Rainfall Measuring Mission (TRMM) 3B42 and 2A25 rain products. The 3B42 rainrates at 3-hourly, 0.25 deg x 0.25 deg spatial resolution for the last 10 years (January 1998 to July 2007) are used to form and analyze the 5-day mean and monthly mean climatology of rainfall. Results show considerable regional and seasonal differences of rainfall over the Mediterranean Region. The maximum rainfall (3-5 mm/day) occurs over the mountain regions of Europe, while the minimum rainfall is observed over North Africa (approximately 0.5 mm/day). The main rainy season over the Mediterranean Sea extends from October to March, with maximum rainfall occurring during November-December. Over the Mediterranean Sea, an average rainrate of approximately 1-2 mm/day is observed, but during the rainy season there is 20% larger rainfall over the western Mediterranean Sea than that over the eastern Mediterranean Sea. During the rainy season, mesoscale rain systems generally propagate from west to east and from north to south over the Mediterranean region, likely to be associated with Mediterranean cyclonic disturbances resulting from interactions among large-scale circulation, orography, and land-sea temperature contrast.

  12. The Version 2 Global Precipitation Climatology Project (GPCP) Monthly Precipitation Analysis (1979-Present)

    Science.gov (United States)

    Adler, Robert F.; Huffman, George J.; Chang, Alfred; Ferraro, Ralph; Xie, Ping-Ping; Janowiak, John; Rudolf, Bruno; Schneider, Udo; Curtis, Scott; Bolvin, David

    2003-01-01

    The Global Precipitation Climatology Project (GPCP) Version 2 Monthly Precipitation Analysis is described. This globally complete, monthly analysis of surface precipitation at 2.5 degrees x 2.5 degrees latitude-longitude resolution is available from January 1979 to the present. It is a merged analysis that incorporates precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit-satellite infrared data, and rain gauge observations. The merging approach utilizes the higher accuracy of the low-orbit microwave observations to calibrate, or adjust, the more frequent geosynchronous infrared observations. The data set is extended back into the premicrowave era (before 1987) by using infrared-only observations calibrated to the microwave-based analysis of the later years. The combined satellite-based product is adjusted by the raingauge analysis. This monthly analysis is the foundation for the GPCP suite of products including those at finer temporal resolution, satellite estimate, and error estimates for each field. The 23-year GPCP climatology is characterized, along with time and space variations of precipitation.

  13. GPS scintillations and total electron content climatology in the southern low, middle and high latitude regions

    Directory of Open Access Journals (Sweden)

    Luca Spogli

    2013-06-01

    Full Text Available In recent years, several groups have installed high-frequency sampling receivers in the southern middle and high latitude regions, to monitor ionospheric scintillations and the total electron content (TEC changes. Taking advantage of the archive of continuous and systematic observations of the ionosphere on L-band by means of signals from the Global Positioning System (GPS, we present the first attempt at ionospheric scintillation and TEC mapping from Latin America to Antarctica. The climatology of the area considered is derived through Ground-Based Scintillation Climatology, a method that can identify ionospheric sectors in which scintillations are more likely to occur. This study also introduces the novel ionospheric scintillation 'hot-spot' analysis. This analysis first identifies the crucial areas of the ionosphere in terms of enhanced probability of scintillation occurrence, and then it studies the seasonal variation of the main scintillation and TEC-related parameters. The results produced by this sophisticated analysis give significant indications of the spatial/ temporal recurrences of plasma irregularities, which contributes to the extending of current knowledge of the mechanisms that cause scintillations, and consequently to the development of efficient tools to forecast space-weather-related ionospheric events.

  14. Evaluation of East Asian Climatology as Simulated by Seven Coupled Models

    Institute of Scientific and Technical Information of China (English)

    JIANG Dabang; WANG Huijun; LANG Xianmei

    2005-01-01

    Using observation and reanalysis data throughout 1961-1990, the East Asian surface air temperature,precipitation and sea level pressure climatology as simulated by seven fully coupled atmosphere-ocean models, namely CCSR/NIES, CGCM2, CSIRO-Mk2, ECHAM4/OPYC3, GFDL-R30, HadCM3, and NCARPCM, are systematically evaluated in this study. It is indicated that the above models can successfully reproduce the annual and seasonal surface air temperature and precipitation climatology in East Asia, with relatively good performance for boreal autumn and annual mean. The models' ability to simulate surface air temperature is more reliable than precipitation. In addition, the models can dependably capture the geographical distribution pattern of annual, boreal winter, spring and autumn sea level pressure in East Asia. In contrast, relatively large simulation errors are displayed when simulated boreal summer sea level pressure is compared with reanalysis data in East Asia. It is revealed that the simulation errors for surface air temperature, precipitation and sea level pressure are generally large over and around the Tibetan Plateau. No individual model is best in every aspect. As a whole, the ECHAM4/OPYC3 and HadCM3 performances are much better, whereas the CGCM2 is relatively poorer in East Asia. Additionally, the seven-model ensemble mean usually shows a relatively high reliability.

  15. Lightning climatology over Jakarta, Indonesia, based on long-term surface operational, satellite, and campaign observations

    Science.gov (United States)

    Mori, Shuichi; Wu, Peiming; Yamanaka, Manabu D.; Hattori, Miki; Hamada, Jun-Ichi; Arbain, Ardhi A.; Lestari, Sopia; Sulistyowati, Reni; Syamsudin, Fadli

    2016-04-01

    Lightning frequency over Indonesian Maritime Continent (MC) is quite high (Petersen and Rutledge 2001, Christian et al. 2003, Takayabu 2006, etc). In particular, Bogor (south of Jakarta, west Jawa) had 322 days of lightning in one year (Guinness Book in 1988). Lightning causes serious damage on nature and society over the MC; forest fore, power outage, inrush/surge currents on many kinds of electronics. Lightning climatology and meso-scale characteristics of thunderstorm over the MC, in particular over Jakarta, where social damage is quite serious, were examined. We made Statistical analysis of lightning and thunderstorm based on TRMM Lightning Image Sensor (LIS) and Global Satellite Mapping of Precipitation (GSMaP) together with long-term operational surface observation data (SYNOP) in terms of diurnal, intraseasonal, monsoonal, and interannual variations. In addition, we carried out a campaign observation in February 2015 in Bogor to obtain meso-scale structure and dynamics of thunderstorm over Jakarta to focus on graupel and other ice phase particles inside by using an X-band dual-polarimetric (DP) radar. Recently, Virts et al. (2013a, b) showed comprehensive lightning climatology based on the World Wide Lightning Location Network (WWLLN). However, they also reported problems with its detection efficiency (Science (JSPS) KAKENHI (Grants-in-Aid for Scientific Research) grant number 25350515 and the Japan Aerospace Exploration Agency (JAXA) 7th Research Announcement (RA).

  16. Reference Solar Radiation Year and Some Climatology Aspects of East Coast of West Malaysia

    Directory of Open Access Journals (Sweden)

    Abdul M. Muzathik

    2010-01-01

    Full Text Available Problem statement: This study examined in detail some aspects of radiation climatology for Terengganu state in Malaysia. The geographical co-ordinates of the site are 5°10’N latitude 103°06’E longitude and 5.2 m altitude. Approach: The data used in the present study were taken from a recording data station installed at site by the Malaysian Meteorology Department (2004. In addition to this, wind speed, solar radiation and air temperature data taken from University Malaysia Terengganu Renewable Energy Station were also analyzed. The averaged solar radiation year for Terengganu is generated from mid-term daily global solar radiation data. The averaged data of the daily global solar radiation for the locations considered are presented in a tabular form for a complete year. Results: The highest daily and monthly mean global solar irradiation values were 7560 and 6566 Wh m-2 day-1, respectively. The highest hourly average solar irradiance intensity was 1139 W m-2 during this study period. Yearly average daily solar energy was 18.92 MJ m-2 day-1. Besides the global solar radiation, the clearness indexes, wind speed and air temperature variation are discussed. Conclusion/Recommendations: The results in this study will fill the gap that complete and detailed reference solar radiation and climatologically data, which are not available for Terengganu state of Malaysia and will be useful to the designers of solar energy conversion and utilization devices.

  17. A global seasonal surface ocean climatology of phytoplankton types based on CHEMTAX analysis of HPLC pigments

    Science.gov (United States)

    Swan, Chantal M.; Vogt, Meike; Gruber, Nicolas; Laufkoetter, Charlotte

    2016-03-01

    Much advancement has been made in recent years in field data assimilation, remote sensing and ecosystem modeling, yet our global view of phytoplankton biogeography beyond chlorophyll biomass is still a cursory taxonomic picture with vast areas of the open ocean requiring field validations. High performance liquid chromatography (HPLC) pigment data combined with inverse methods offer an advantage over many other phytoplankton quantification measures by way of providing an immediate perspective of the whole phytoplankton community in a sample as a function of chlorophyll biomass. Historically, such chemotaxonomic analysis has been conducted mainly at local spatial and temporal scales in the ocean. Here, we apply a widely tested inverse approach, CHEMTAX, to a global climatology of pigment observations from HPLC. This study marks the first systematic and objective global application of CHEMTAX, yielding a seasonal climatology comprised of ~1500 1°×1° global grid points of the major phytoplankton pigment types in the ocean characterizing cyanobacteria, haptophytes, chlorophytes, cryptophytes, dinoflagellates, and diatoms, with results validated against prior regional studies where possible. Key findings from this new global view of specific phytoplankton abundances from pigments are a) the large global proportion of marine haptophytes (comprising 32±5% of total chlorophyll), whose biogeochemical functional roles are relatively unknown, and b) the contrasting spatial scales of complexity in global community structure that can be explained in part by regional oceanographic conditions. The results are publically accessible via

  18. Low cloud precipitation climatology in the southeastern Pacific marine stratocumulus region using CloudSat

    International Nuclear Information System (INIS)

    A climatology of low cloud surface precipitation occurrence and intensity from the new CloudSat 2C-RAIN-PROFILE algorithm is presented from June 2006 through December 2010 for the southeastern Pacific region of marine stratocumulus. Results show that over 70% of low cloud precipitation falls as drizzle. Application of an empirical evaporation model suggests that 50–80% of the precipitation evaporates before it reaches the surface. Segregation of the CloudSat ascending and descending overpasses shows that the majority of precipitation occurs at night. Examination of the seasonal cycle shows that the precipitation is most frequent during the austral winter and spring; however there is considerable regional variability. Conditional rain rates increase from east to west with a maximum occurring in the region influenced by the South Pacific Convergence Zone. Area average rain rates are highest in the region where precipitation rates are moderate, but most frequent. The area average surface rain rate for low cloud precipitation for this region is ∼0.22 mm d−1, in good agreement with in situ estimates, and is greatly improved over earlier CloudSat precipitation products. These results provide a much-needed quantification of surface precipitation in a region that is currently underestimated in existing satellite-based precipitation climatologies. (letter)

  19. Exploratory study on the influence of climatological parameters on Mycoplasma hyopneumoniae infection dynamics

    Science.gov (United States)

    Segalés, Joaquim; Valero, Oliver; Espinal, Anna; López-Soria, Sergio; Nofrarías, Miquel; Calsamiglia, Maria; Sibila, Marina

    2012-11-01

    The objective of the present work was to elucidate the potential relationship between Mycoplasma hyopneumoniae infection and seroconversion dynamics and climatological conditions in four groups of pigs from the same farm born in different seasons of the year. Nasal swabs and blood samples were taken from 184 pigs at 1, 3, 6, 9, 12, 15, 18, 22 and 25 (slaughter age) weeks of age. Outside climatologic parameters, including temperature (°C), relative humidity (%), precipitation (l/m2) and wind speed (m/s) were recorded weekly from January 2003 to June 2004. Percentage of nPCR detection of M. hyopneumoniae in nasal swabs was associated significantly with the weekly precipitation rate [ P = 0.0018, OR = 1.31 (IC = 1.11-1.55)]; the higher the precipitation rate, the higher the probability of being M. hyopneumoniae nPCR-positive. On the other hand, the percentage of seropositive pigs had a significant association with mean weekly temperature rate [ P = 0.0012, OR = 0.89 [IC = 0.84-0.95]); the lower the temperature, the higher the probability of being M. hyopneumoniae seropositive. Animals born in autumn (when higher precipitations rates were recorded), entering finishing units in winter (when lower temperatures were recorded), and reaching slaughter in spring, had the highest probability of being infected by M. hyopneumoniae and the highest probability of being M. hyopneumoniae seropositive.

  20. Climatological features of WRF-simulated tropical cyclones over the western North Pacific

    Science.gov (United States)

    Kim, Dasol; Jin, Chun-Sil; Ho, Chang-Hoi; Kim, Jinwon; Kim, Joo-Hong

    2014-11-01

    Tropical cyclones (TCs) over the western North Pacific (WNP) are simulated for the 29 TC seasons of July-October from 1982 to 2010 using the regional Weather Research and Forecasting (WRF) model nested within global WRF model simulations. Averaged over the entire 29-year period, the nested global-regional WRF has reasonably simulated the climatology of key TC features such as the location/frequency of genesis and tracks. The dynamical and thermal structures of the simulated TCs are weaker than observations owing to the coarse spatial resolution of the regional WRF (50 km × 50 km). TC frequencies are somewhat underestimated over the East China Sea but are substantially overestimated over the South China Sea and the Philippine Sea with neighboring oceans between 10°N and 15°N. Categorization of the simulated TCs into six clusters based on the observed TC clusters and the associated large-scale circulation show that the nested simulation depicts the observed TC characteristics well except for two clusters associated with TCs traveling from the Philippine Sea to the East China Sea. Errors in the simulated TC genesis and tracks are mostly related to these two clusters. In the simulation, the monsoon confluent zone over the Philippine Sea is too strong, and the mid-latitude jet stream expands farther south than that in the observations. Overall results from this study suggest that the nested global-regional WRF can be useful for studying the TC climatology over the WNP.

  1. Climatological Processing and Product Development for the TRMM Ground Validation Program

    Science.gov (United States)

    Marks, D. A.; Kulie, M. S.; Robinson, M.; Silberstein, D. S.; Wolff, D. B.; Ferrier, B. S.; Amitai, E.; Fisher, B.; Wang, J.; Augustine, D.; Thiele, O.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The Tropical Rainfall Measuring Mission (TRMM) satellite was successfully launched in November 1997.The main purpose of TRMM is to sample tropical rainfall using the first active spaceborne precipitation radar. To validate TRMM satellite observations, a comprehensive Ground Validation (GV) Program has been implemented. The primary goal of TRMM GV is to provide basic validation of satellite-derived precipitation measurements over monthly climatologies for the following primary sites: Melbourne, FL; Houston, TX; Darwin, Australia- and Kwajalein Atoll, RMI As part of the TRMM GV effort, research analysts at NASA Goddard Space Flight Center (GSFC) generate standardized rainfall products using quality-controlled ground-based radar data from the four primary GV sites. This presentation will provide an overview of TRMM GV climatological processing and product generation. A description of the data flow between the primary GV sites, NASA GSFC, and the TRMM Science and Data Information System (TSDIS) will be presented. The radar quality control algorithm, which features eight adjustable height and reflectivity parameters, and its effect on monthly rainfall maps, will be described. The methodology used to create monthly, gauge-adjusted rainfall products for each primary site will also be summarized. The standardized monthly rainfall products are developed in discrete, modular steps with distinct intermediate products. A summary of recently reprocessed official GV rainfall products available for TRMM science users will be presented. Updated basic standardized product results involving monthly accumulation, Z-R relationship, and gauge statistics for each primary GV site will also be displayed.

  2. Antarctic icebergs melt over the Southern Ocean : Climatology and impact on sea ice

    Science.gov (United States)

    Merino, Nacho; Le Sommer, Julien; Durand, Gael; Jourdain, Nicolas C.; Madec, Gurvan; Mathiot, Pierre; Tournadre, Jean

    2016-08-01

    Recent increase in Antarctic freshwater release to the Southern Ocean is suggested to contribute to change in water masses and sea ice. However, climate models differ in their representation of the freshwater sources. Recent improvements in altimetry-based detection of small icebergs and in estimates of the mass loss of Antarctica may help better constrain the values of Antarctic freshwater releases. We propose a model-based seasonal climatology of iceberg melt over the Southern Ocean using state-of-the-art observed glaciological estimates of the Antarctic mass loss. An improved version of a Lagrangian iceberg model is coupled with a global, eddy-permitting ocean/sea ice model and compared to small icebergs observations. Iceberg melt increases sea ice cover, about 10% in annual mean sea ice volume, and decreases sea surface temperature over most of the Southern Ocean, but with distinctive regional patterns. Our results underline the importance of improving the representation of Antarctic freshwater sources. This can be achieved by forcing ocean/sea ice models with a climatological iceberg fresh-water flux.

  3. Toward a Multi-Decadal Climatology of North Pacific Polar Lows Employing Dynamical Downscaling

    Directory of Open Access Journals (Sweden)

    Fei Chen

    2012-01-01

    Full Text Available The North Pacific is an area where sub-synoptic Polar Lows frequently form during the cold season, especially over the Bering Sea, Gulf of Alaska and Japan Sea. So far, a multi-decadal climatology of such Polar Lows based on individual cases has not been assembled. Here, we consider dynamical downscaling method for realistically constructing the formation and life cycles of such lows over the past 6 decades without exploiting sub-synoptic information in initial fields. To do so, a regional climate model is conditioned by large-scale information of NCEP re-analyses. We test the approach by examining its skill in simulating ten known cases of North Pacific Polar Lows. Three of these are discussed in some detail. The signatures of all storms emerge in the simulations with additional sub-synoptic details. The tracks of the simulated Polar Lows closely follow the tracks derived from satellite imagery. We conclude that the suggested method is suitable for constructing multi-decade climatologies, including trends and variability, of Polar Lows in the North Pacific by dynamically downscaling NCEP re-analyses.

  4. Climatological response of Indian low-latitude ionosphere to geomagnetic storms

    Science.gov (United States)

    Suresh, Sunanda; Dashora, N.

    2016-05-01

    A climatological response of low-latitude ionosphere to geomagnetic storms is presented using long-term global ionospheric maps data from June 1998 to June 2015 covering two solar cycles 23 and 24. The results are presented for daytime forenoon and afternoon sectors under minor, moderate, and major ionospheric storm categories based on minimum Dst index criterion. For the first time the effectiveness of storms is identified using monthly standard deviation as an indicator of the day to day variability in equatorial and low-latitude ionosphere. Thus, results on climatology are definitive and form a database that would be comparable to statistical results from any other longitude and time. Seasonal statistics for total storms, effective positive and negative storms, and amplitude of mean seasonal perturbation in total electron content are obtained. Total and effective storms are found to be higher in solar cycle 23 than in 24 and only a couple of effective storms occurred during low solar activity 2007-2009 that too in minor category. Afternoon sector is found to be favorable for occurrence of maximum number of effective positive storms. A latitudinal preference is found for a given storm to be effective in either time sectors. Equinoctial asymmetry in ionospheric response both in terms of occurrence and perturbation amplitude is found. September equinoxes are found to bear maximum total, effective positive and negative storms. Winters are found more prone to negative storms, whereas summers have recorded minimum number of either of storms and minimum perturbation amplitudes.

  5. 1958-2006 Precipitation Climatology for Lawrence Livermore National Laboratory Livermore Site and Site 300

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, B M

    2006-12-19

    This report contains rainfall climatology and analyses during the period from 1958 to 2006 for the two sites of Lawrence Livermore National Laboratory: the Livermore site and Site 300. The measurement sites are described, a regional climatology overview is provided, and the effect of topography on regional precipitation is discussed. Rainfall statistics are presented including monthly normals (30-year means) and medians; percentages of time that rainfall is less than or equal to specified amounts for given months, years, and seasons; and mean, median, and maximum numbers of days of precipitation for specified amounts by month, year, and season. The rainfall pattern is demonstrated to be typical of Mediterranean climates, with most rain falling during the cold season. Nearly 80% of seasonal rainfall occurs during November through March, with the average annual rainfall equaling 13.62 and 10.64 inches at the Livermore site and Site 300, respectively. Precipitation frequency and extreme value analyses for durations ranging from 15 minutes to 24 hours, month, and rainfall season are shown in order to estimate rainfall amounts for return periods of two to 100 years at both sites. This analysis determined 100-year return periods for largest 24-hour rainfalls of 2.49 and 2.22 inches at the Livermore site and Site 300, respectively. Historical analysis of seasonal rainfall data indicates that the wettest rainfall seasons at both sites typically occurred during strong El Ninos.

  6. Diva software, a tool for European regional seas and Ocean climatologies production

    Science.gov (United States)

    Ouberdous, M.; Troupin, C.; Barth, A.; Alvera-Azcàrate, A.; Beckers, J.-M.

    2012-04-01

    Diva (Data-Interpolating Variational Analysis) is a software based on a method designed to perform data-gridding (or analysis) tasks, with the assets of taking into account the intrinsic nature of oceanographic data, i.e., the uncertainty on the in situ measurements and the anisotropy due to advection and irregular coastlines and topography. The Variational Inverse Method (VIM, Brasseur et al., 1996) implemented in Diva consists in minimizing a variational principle which accounts for the differences between the observations and the reconstructed field, the influence of the gradients and variability of the reconstructed field. The resolution of the numerical problem is based on finite-element method, which allows a great numerical efficiency and the consideration of complicated contours. Along with the analysis, Diva provides also error fields (Brankart and Brasseur, 1998; Rixen et al., 2000) based on the data coverage and noise. Diva is used for the production of climatologies in the pan-European network SeaDataNet. SeaDataNet is connecting the existing marine data centres of more than 30 countries and set up a data management infrastructure consisting of a standardized distributed system. The consortium has elaborated integrated products, using common procedures and methods. Among these, it uses the Diva software as reference tool for climatologies computation for various European regional seas, the Atlantic and the global ocean. During the first phase of the SeaDataNet project, a number of additional tools were developed to make easier the climatologies production for the users. Among these tools: the advection constraint during the field reconstruction through the specification of a velocity field on a regular grid, forcing the analysis to align with the velocity vectors; the Generalized Cross Validation for the determination of analysis parameters (signal-to-noise ratio); the creation of contours at selected depths; the detection of possible outliers; the

  7. MERIS albedo climatology for FRESCO+ O2 A-band cloud retrieval

    Directory of Open Access Journals (Sweden)

    Y. Zhou

    2011-03-01

    Full Text Available A new global albedo climatology for Oxygen A-band cloud retrievals is presented. The climatology is based on MEdium Resolution Imaging Spectrometer (MERIS Albedomap data and its favourable impact on the derivation of cloud fraction is demonstrated for the FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A-band algorithm. To date, a relatively coarse resolution (1° × 1° surface reflectance dataset from GOME (Global Ozone Monitoring Experiment Lambert-equivalent reflectivity (LER is used in FRESCO+. The GOME LER climatology does not account for the usually higher spatial resolution of UV/VIS instruments designed for trace gas remote sensing which introduces several artefacts, e.g. in regions with sharp spectral contrasts like coastlines or over bright surface targets. Therefore, MERIS black-sky albedo (BSA data from the period October 2002 to October 2006 were aggregated to a grid of 0.25° × 0.25° for each month of the year and for different spectral channels. In contrary to other available surface reflectivity datasets, MERIS includes channels at 754 nm and 775 nm which are located close to the spectral windows required for O2 A-band cloud retrievals. The MERIS BSA in the near-infrared compares well to Moderate Resolution Imaging Spectroradiometer (MODIS derived BSA with an average difference lower than 1% and a correlation coefficient of 0.98. However, when relating MERIS BSA to GOME LER a distinctly lower correlation (0.80 and enhanced scatter is found. Effective cloud fractions from two exemplary months (January and July 2006 of Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY data were subsequently derived with FRESCO+ and compared to those from the Heidelberg Iterative Cloud Retrieval Utilities (HICRU algorithm. The MERIS climatology generally improves FRESCO+ effective cloud fractions. In particular small cloud fractions are in better agreement with HICRU. This is of importance for atmospheric

  8. A global drought climatology for the 3rd edition of the World Atlas of Desertification (WAD)

    Science.gov (United States)

    Spinoni, Jonathan; Carrao, Hugo; Naumann, Gustavo; Antofie, Tiberiu; Barbosa, Paulo; Vogt, Jürgen

    2013-04-01

    A new version of the World Atlas of Desertification (WAD) is being compiled in the framework of cooperation between the Joint Research Centre (JRC) of the European Commission and the United Nations Environment Programme (UNEP). This initiative aims at mapping the global land degradation and desertification, as well as introducing the reader with complex interactions of geo-physical, socio-economic, and political aspects that affect the environmental sustainability. Recurrent extreme events resulting from climate change, such as more severe droughts, combined with non-adapted land use practices can affect the resilience of ecosystems tipping them into a less productive state. Thus, to describe the effects of climatological hazards on land degradation and desertification processes, we computed a World drought climatology that will be part of the 3rd edition of the WAD and will replace and update to 2010 the results presented in the 2nd edition in 1997. This paper presents the methodology used to compute three parameters included in the WAD drought climatology, i.e. drought frequency, intensity and duration, and discusses their spatio-temporal patterns both at global and continental scales. Because drought is mainly driven and triggered by a rainfall deficit, we chose the Standardized Precipitation Index (SPI) as the drought indicator to estimate our climatological parameters. The SPI is a statistical precipitation-based drought indicator widely used in drought-related studies. We calculated the SPI on three different accumulation periods: 3 months (SPI-3), 6 months (SPI-6), and 12 months (SPI-12), in order to take into account meteorological, agricultural, and hydrological drought-related features. Each quantity has been calculated on a monthly basis using the baseline period between January 1951 and December 2010. As data input, we used the Full Data Reanalysis Version 6.0 (0.5˚x0.5˚) of gridded monthly precipitation provided by the Global Precipitation

  9. A Prototype Hail Detection Algorithm and Hail Climatology Developed with the Advanced Microwave Sounding Unit (AMSU)

    Science.gov (United States)

    Ferraro, Ralph; Beauchamp, James; Cecil, Dan; Heymsfeld, Gerald

    2015-01-01

    In previous studies published in the open literature, a strong relationship between the occurrence of hail and the microwave brightness temperatures (primarily at 37 and 85 GHz) was documented. These studies were performed with the Nimbus-7 SMMR, the TRMM Microwave Imager (TMI) and most recently, the Aqua AMSR-E sensor. This lead to climatologies of hail frequency from TMI and AMSR-E, however, limitations include geographical domain of the TMI sensor (35 S to 35 N) and the overpass time of the Aqua satellite (130 am/pm local time), both of which reduce an accurate mapping of hail events over the global domain and the full diurnal cycle. Nonetheless, these studies presented exciting, new applications for passive microwave sensors. Since 1998, NOAA and EUMETSAT have been operating the AMSU-A/B and the MHS on several operational satellites: NOAA-15 through NOAA-19; MetOp-A and -B. With multiple satellites in operation since 2000, the AMSU/MHS sensors provide near global coverage every 4 hours, thus, offering a much larger time and temporal sampling than TRMM or AMSR-E. With similar observation frequencies near 30 and 85 GHz and additionally three at the 183 GHz water vapor band, the potential to detect strong convection associated with severe storms on a more comprehensive time and space scale exists. In this study, we develop a prototype AMSU-based hail detection algorithm through the use of collocated satellite and surface hail reports over the continental U.S. for a 12-year period (2000-2011). Compared with the surface observations, the algorithm detects approximately 40 percent of hail occurrences. The simple threshold algorithm is then used to generate a hail climatology that is based on all available AMSU observations during 2000-11 that is stratified in several ways, including total hail occurrence by month (March through September), total annual, and over the diurnal cycle. Independent comparisons are made compared to similar data sets derived from other

  10. Mars Sample Return: The Next Step Required to Revolutionize Knowledge of Martian Geological and Climatological History

    Science.gov (United States)

    Mittlefehldt, D. W.

    2012-01-01

    The capability of scientific instrumentation flown on planetary orbiters and landers has made great advances since the signature Viking mission of the seventies. At some point, however, the science return from orbital remote sensing, and even in situ measurements, becomes incremental, rather than revolutionary. This is primarily caused by the low spatial resolution of such measurements, even for landed instrumentation, the incomplete mineralogical record derived from such measurements, the inability to do the detailed textural, mineralogical and compositional characterization needed to demonstrate equilibrium or reaction paths, and the lack of chronological characterization. For the foreseeable future, flight instruments will suffer from this limitation. In order to make the next revolutionary breakthrough in understanding the early geological and climatological history of Mars, samples must be available for interrogation using the full panoply of laboratory-housed analytical instrumentation. Laboratory studies of samples allow for determination of parageneses of rocks through microscopic identification of mineral assemblages, evaluation of equilibrium through electron microbeam analyses of mineral compositions and structures, determination of formation temperatures through secondary ion or thermal ionization mass spectrometry (SIMS or TIMS) analyses of stable isotope compositions. Such details are poorly constrained by orbital data (e.g. phyllosilicate formation at Mawrth Vallis), and incompletely described by in situ measurements (e.g. genesis of Burns formation sediments at Meridiani Planum). Laboratory studies can determine formation, metamorphism and/or alteration ages of samples through SIMS or TIMS of radiogenic isotope systems; a capability well-beyond flight instrumentation. Ideally, sample return should be from a location first scouted by landers such that fairly mature hypotheses have been formulated that can be tested. However, samples from clastic

  11. Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies

    Directory of Open Access Journals (Sweden)

    L. Hoffmann

    2014-06-01

    Full Text Available Chlorofluorocarbons (CFCs play a key role in stratospheric ozone loss and are strong infrared absorbers that contribute to global warming. The stratospheric lifetimes of CFCs are a measure of their global loss rates that are needed to determine global warming and ozone depletion potentials. We applied the tracer-tracer correlation approach to zonal mean climatologies from satellite measurements and model data to assess the lifetimes of CFCl3 (CFC-11 and CF2Cl2 (CFC-12. We present estimates of the CFC-11/CFC-12 lifetime ratio and the absolute lifetime of CFC-12, based on a reference lifetime of 52 yr for CFC-11. We analyzed climatologies from three satellite missions, the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS, the HIgh Resolution Dynamics Limb Sounder (HIRDLS, and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. We found a CFC-11/CFC-12 lifetime ratio of 0.47±0.08 and a CFC-12 lifetime of 111(96–132 yr for ACE-FTS, a ratio of 0.46±0.07 and a lifetime of 112(97–133 yr for HIRDLS, and a ratio of 0.46±0.08 and a lifetime of 112(96–135 yr for MIPAS. The error-weighted, combined CFC-11/CFC-12 lifetime ratio is 0.47±0.04 and the CFC-12 lifetime estimate is 112(102–123 yr. These results agree with the recent Stratosphere-troposphere Processes And their Role in Climate (SPARC reassessment, which recommends lifetimes of 52(43–67 yr and 102(88–122 yr, respectively. Having smaller uncertainties than the results from other recent studies, our estimates can help to better constrain CFC-11 and CFC-12 lifetime recommendations in future scientific studies and assessments. Furthermore, the satellite observations were used to validate first simulation results from a new coupled model system, which integrates a Lagrangian chemistry transport model into a climate model. For the coupled model we found a CFC-11/CFC-12 lifetime ratio of 0.48±0.07 and a CFC-12 lifetime of 110(95–129 yr, based on

  12. Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies

    Directory of Open Access Journals (Sweden)

    L. Hoffmann

    2014-11-01

    Full Text Available Chlorofluorocarbons (CFCs play a key role in stratospheric ozone loss and are strong infrared absorbers that contribute to global warming. The stratospheric lifetimes of CFCs are a measure of their stratospheric loss rates that are needed to determine global warming and ozone depletion potentials. We applied the tracer–tracer correlation approach to zonal mean climatologies from satellite measurements and model data to assess the lifetimes of CFCl3 (CFC-11 and CF2Cl2 (CFC-12. We present estimates of the CFC-11/CFC-12 lifetime ratio and the absolute lifetime of CFC-12, based on a reference lifetime of 52 years for CFC-11. We analyzed climatologies from three satellite missions, the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS, the HIgh Resolution Dynamics Limb Sounder (HIRDLS, and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. We found a CFC-11/CFC-12 lifetime ratio of 0.47±0.08 and a CFC-12 lifetime of 112(96–133 years for ACE-FTS, a ratio of 0.46±0.07 and a lifetime of 113(97–134 years for HIRDLS, and a ratio of 0.46±0.08 and a lifetime of 114(98–136 years for MIPAS. The error-weighted, combined CFC-11/CFC-12 lifetime ratio is 0.46±0.04 and the CFC-12 lifetime estimate is 113(103–124 years. These results agree with the recent Stratosphere-troposphere Processes And their Role in Climate (SPARC reassessment, which recommends lifetimes of 52(43–67 years and 102(88–122 years, respectively. Having smaller uncertainties than the results from other recent studies, our estimates can help to better constrain CFC-11 and CFC-12 lifetime recommendations in future scientific studies and assessments. Furthermore, the satellite observations were used to validate first simulation results from a new coupled model system, which integrates a Lagrangian chemistry transport model into a climate model. For the coupled model we found a CFC-11/CFC-12 lifetime ratio of 0.48±0.07 and a CFC-12 lifetime

  13. Climatologies from satellite measurements: the impact of orbital sampling on the standard error of the mean

    Directory of Open Access Journals (Sweden)

    M. Toohey

    2013-04-01

    Full Text Available Climatologies of atmospheric observations are often produced by binning measurements according to latitude and calculating zonal means. The uncertainty in these climatological means is characterised by the standard error of the mean (SEM. However, the usual estimator of the SEM, i.e., the sample standard deviation divided by the square root of the sample size, holds only for uncorrelated randomly sampled measurements. Measurements of the atmospheric state along a satellite orbit cannot always be considered as independent because (a the time-space interval between two nearest observations is often smaller than the typical scale of variations in the atmospheric state, and (b the regular time-space sampling pattern of a satellite instrument strongly deviates from random sampling. We have developed a numerical experiment where global chemical fields from a chemistry climate model are sampled according to real sampling patterns of satellite-borne instruments. As case studies, the model fields are sampled using sampling patterns of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS and Atmospheric Chemistry Experiment Fourier-Transform Spectrometer (ACE-FTS satellite instruments. Through an iterative subsampling technique, and by incorporating information on the random errors of the MIPAS and ACE-FTS measurements, we produce empirical estimates of the standard error of monthly mean zonal mean model O3 in 5° latitude bins. We find that generally the classic SEM estimator is a conservative estimate of the SEM, i.e., the empirical SEM is often less than or approximately equal to the classic estimate. Exceptions occur only when natural variability is larger than the random measurement error, and specifically in instances where the zonal sampling distribution shows non-uniformity with a similar zonal structure as variations in the sampled field, leading to maximum sensitivity to arbitrary phase shifts between the sample distribution and

  14. Climatological changing effects on wind, precipitation and erosion: Large, meso and small scale analysis

    International Nuclear Information System (INIS)

    The Fourier transformation analysis for monthly average values of meteorological parameters has been considered, and amplitudes, phase angles have been calculated by using ground measurements in Turkey. The first order harmonics of meteorological parameters show large scale effects, while higher order harmonics show the effects of small scale fluctuations. The variations of first through sixth order harmonic amplitudes and phases provide a useful means of understanding the large and local scale effects on meteorological parameters. The phase angle can be used to determine the time of year the maximum or minimum of a given harmonic occurs. The analysis helps us to distinguish different pressure, relative humidity, temperature, precipitation and wind speed regimes and transition regions. Local and large scale phenomenon and some unusual seasonal patterns are also defined near Keban Dam and the irrigation area. Analysis of precipitation based on long term data shows that semi-annual fluctuations are predominant in the study area. Similarly, pressure variations are mostly influenced by semi-annual fluctuations. Temperature and humidity variations are mostly influenced by meso and micro scale fluctuations. Many large and meso scale climate change simulations for the 21st century are based on concentration of green house gases. A better understanding of these effects on soil erosion is necessary to determine social, economic and other impacts of erosion. The second part of this study covers the time series analysis of precipitation, rainfall erosivity and wind erosion at the Marmara Region. Rainfall and runoff erosivity factors are defined by considering the results of field measurements at 10 stations. Climatological changing effects on rainfall erosion have been determined by monitoring meteorological variables. In the previous studies, Fournier Index is defined to estimate the rainfall erosivity for the study area. The Fournier Index or in other words a climatic index

  15. Modeling drought impact occurrence based on climatological drought indices for four European countries

    Science.gov (United States)

    Stagge, James H.; Kohn, Irene; Tallaksen, Lena M.; Stahl, Kerstin

    2014-05-01

    The relationship between atmospheric conditions and the likelihood of a significant drought impact has, in the past, been difficult to quantify, particularly in Europe where political boundaries and language have made acquiring comprehensive drought impact information difficult. As such, the majority of studies linking meteorological drought with the occurrence or severity of drought impacts have previously focused on specific regions, very detailed impact types, or both. This study describes a new methodology to link the likelihood of drought impact occurrence with climatological drought indices across different European climatic regions and impact sectors using the newly developed European Drought Impact report Inventory (EDII), a collaborative database of drought impact information (www.geo.uio.no/edc/droughtdb/). The Standardized Precipitation Index (SPI) and Standardized Precipitation-Evapotranspiration Index (SPEI) are used as predictor variables to quantify meteorological drought severity over prior time periods (here 1, 2, 3, 6, 9, 12, and 24 months are used). The indices are derived using the gridded WATCH Forcing Datasets, covering the period 1958-2012. Analysis was performed using logistic regression to identify the climatological drought index and accumulation period, or linear combination of drought indices, that best predicts the likelihood of a documented drought impact, defined by monthly presence/absence. The analysis was carried out for a subset of four European countries (Germany, UK, Norway, Slovenia) and four of the best documented impact sectors: Public Water Supply, Agriculture and Livestock Farming, Energy and Industry, and Environmental Quality. Preliminary results show that drought impacts in these countries occur most frequently due to a combination of short-term (2-6 month) precipitation deficits and long-term (12-24 month) potential evapotranspiration anomaly, likely associated with increased temperatures. Agricultural drought impacts

  16. The temporal and spatial relationship between NDVI and climatological parameters in Colorado

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper describes the spatial and temporal relationship between AVHRR/NDVI (Normalized Difference Vegetation Index) and climatological parameters (temperature and precipitation), which, in some sense, is influenced by topographical factors and land-cover types in Colorado. The correlation coefficients and partial correlation coefficients have been computed pixel by pixel over Colorado in order to analyze the relationship. The temporal variation and correlation of AVHRR/NDVI, temperature and precipitation were analyzed with a sampling method. The study reveals that there exists a close correspondence between monthly NDVI and temperature, which has strong impact from temperature on the changes of NDVI in Colorado. The spatial changes of NDVI are not influenced obviously by the precipitation since these two variables are different from each other in time series in Colorado. The study clearly revealed the spatial variation and its distribution patterns of relationship between NDVI and climatic parameters (temperature and precipitation) in Colorado.

  17. Lightning climatology of exoplanets and brown dwarfs guided by Solar System data

    CERN Document Server

    Hodosán, Gabriella; Asensio-Torres, Rubén; Vorgul, Irena; Rimmer, Paul B

    2016-01-01

    Clouds form on extrasolar planets and brown dwarfs where lightning could occur. Lightning is a tracer of atmospheric convection, cloud formation and ionization processes as known from the Solar System, and may be significant for the formation of prebiotic molecules. We study lightning climatology for the different atmospheric environments of Earth, Venus, Jupiter and Saturn. We present lightning distribution maps for Earth, Jupiter and Saturn, and flash densities for these planets and Venus, based on optical and/or radio measurements from the WWLLN and STARNET radio networks, the LIS/OTD satellite instruments, the Galileo, Cassini, New Horizons and Venus Express spacecraft. We also present flash densities calculated for several phases of two volcano eruptions, Eyjafjallaj\\"okull's (2010) and Mt Redoubt's (2009). We estimate lightning rates for sample, transiting and directly imaged extrasolar planets and brown dwarfs. Based on the large variety of exoplanets, six categories are suggested for which we use the ...

  18. NEWS Climatology Project: The State of the Water Cycle at Continental to Global Scales

    Science.gov (United States)

    Rodell, Matthew; LEcuyer, Tristan; Beaudoing, Hiroko Kato; Olson, Bill

    2011-01-01

    NASA's Energy and Water Cycle Study (NEWS) program fosters collaborative research towards improved quantification and prediction of water and energy cycle consequences of climate change. In order to measure change, it is first necessary to describe current conditions. The goal of the NEWS Water and Energy Cycle Climatology project is to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. The project is a multiinstitutional collaboration with more than 20 active contributors. This presentation will describe results of the first stage of the water budget analysis, whose goal was to characterize the current state of the water cycle on mean monthly, continental scales. We examine our success in closing the water budget within the expected uncertainty range and the effects of forcing budget closure as a method for refining individual flux estimates.

  19. Steps Toward an EOS-Era Aerosol Air Mass Type Climatology

    Science.gov (United States)

    Kahn, Ralph A.

    2012-01-01

    We still have a way to go to develop a global climatology of aerosol type from the EOS-era satellite data record that currently spans more than 12 years of observations. We have demonstrated the ability to retrieve aerosol type regionally, providing a classification based on the combined constraints on particle size, shape, and single-scattering albedo (SSA) from the MISR instrument. Under good but not necessarily ideal conditions, the MISR data can distinguish three-to-five size bins, two-to-four bins in SSA, and spherical vs. non-spherical particles. However, retrieval sensitivity varies enormously with scene conditions. So, for example, there is less information about aerosol type when the mid-visible aerosol optical depth (AOD) is less that about 0.15 or 0.2.

  20. Progress Toward a Global, EOS-Era Aerosol Air Mass Type Climatology

    Science.gov (United States)

    Kahn, Ralph A.

    2012-01-01

    The MISR and MODIS instruments aboard the NASA Earth Observing System's Terra Satellite have been collecting data containing information about the state of Earth's atmosphere and surface for over eleven years. Data from these instruments have been used to develop a global, monthly climatology of aerosol amount that is widely used as a constraint on climate models, including those used for the 2007 IPCC assessment report. The next frontier in assessing aerosol radiative forcing of climate is aerosol type, and in particular, the absorption properties of major aerosol air masses. This presentation will focus on the prospects for constraining aerosol type globally, and the steps we are taking to apply a combination of satellite and suborbital data to this challenge.

  1. Climatology of GNPs ionospheric scintillation at high and mid latitudes under different solar activity conditions

    International Nuclear Information System (INIS)

    We analyze data of ionospheric scintillation over North European regions for the same period (October to November) of two different years (2003 and 2008), characterized by different geomagnetic conditions. The work aims to develop a scintillation climatology of the high- and mid-latitude ionosphere, analyzing the behaviour of the scintillation occurrence as a function of the magnetic local time (MLT) and of the altitude adjusted corrected magnetic latitude (M lat), to characterize scintillation scenarios under different solar activity conditions. The results shown herein are obtained merging observations from a network of GISTMs (GPS Ionospheric Scintillation and TEC Monitor) located over a wide range of latitudes in the northern hemisphere. Our findings confirm the associations of the occurrence of the ionospheric irregularities with the expected position of the auroral oval and of the ionospheric trough walls and show the contribution of the polar cap patches even under solar minimum conditions.

  2. Does the Danube exist? Versions of reality given by various regional climate models and climatological datasets

    CERN Document Server

    Lucarini, V; Kriegerova, I; Speranza, A; Danihlik, Robert; Kriegerova, Ida; Lucarini, Valerio; Speranza, Antonio

    2006-01-01

    We present an intercomparison and verification analysis of several regional climate models (RCMs) nested into the same run of the same Atmospheric Global Circulation Model (AGCM) regarding their representation of the statistical properties of the hydrological balance of the Danube river basin for 1961-1990. We also consider the datasets produced by the driving AGCM, from the ECMWF and NCEP-NCAR reanalyses. The hydrological balance is computed by integrating the precipitation and evaporation fields over the area of interest. Large discrepancies exist among RCMs for the monthly climatology as well as for the mean and variability of the annual balances, and only few datasets are consistent with the observed discharge values of the Danube at its Delta, even if the driving AGCM provides itself an excellent estimate. Since the considered approach relies on the mass conservation principle and bypasses the details of the air-land interface modeling, we propose that the atmospheric components of RCMs still face diffic...

  3. Climatologically tuned reflectivity-rain rate relations and links to area-time integrals

    Science.gov (United States)

    Atlas, David; Rosenfeld, Daniel; Wolff, David B.

    1990-01-01

    An effort is made to determine relationships between reflectivity (Z) and rain rate (R) which are tuned to the local climatology. The development of such relations was motivated by the need to understand the role of precipitation in controlling general circulation and in affecting such phenomena as ENSO. Attention is given to methods of deriving such relations and how they are linked to area integral rainfall measurements. In essence, the relation is tuned so that the probability distribution of reflectivity, P(Z), replicates that of R over some predetermined space-time climatic domain. Thus, the accurate measurement of the average R over any smaller domain depends on how closely the sampled P(Z) approximates the climatic P(Z). The probability matching method used is a modification of the approach of Calheiros and Zawadzki (1987) and Rosenfeld (1980). The technique is applied to data from Germany and the eastern tropical Atlantic (GATE).

  4. An updated analysis of the Lucas Heights climatology 1991-2003

    International Nuclear Information System (INIS)

    Meteorological data collected from 1991 to 2003 in the Lucas Heights region have been summarised to provide an update on the climatology. This report represents analysis of data collected at the Lucas Heights Science and Technology Centre since 1991 when an advanced digital recording system was installed. The small network of meteorological stations installed in the surrounding region since 1993 has allowed an investigation of the influence of complex terrain on wind flow and atmospheric dispersion patterns. For a period between 1999 and 2001 a Bureau of Meteorology disdrometer was installed at Lucas Heights to investigate raindrop size distributions. A large number of statistical summaries for all meteorological data are presented in in two appendices at the end of the report as a resource for reference purposes

  5. Subvisual-thin cirrus lidar dataset for satellite verification and climatological research

    Science.gov (United States)

    Sassen, Kenneth; Cho, Byung S.

    1992-01-01

    A polarization (0.694 microns wavelength) lidar dataset for subvisual and thin (bluish-colored) cirrus clouds is drawn from project FIRE (First ISCCP Regional Experiment) extended time observations. The clouds are characterized by their day-night visual appearance; base, top, and optical midcloud heights and temperatures; measured physical and estimated optical cloud thicknesses; integrated linear depolarization ratios; and derived k/2 eta ratios. A subset of the data supporting 30 NOAA polar-orbiting satellite overpasses is given in tabular form to provide investigators with the means to test cloud retrieval algorithms and establish the limits of cirrus detectability from satellite measurements under various conditions. Climatologically, subvisual-thin cirrus appear to be higher, colder, and more strongly depolarizing than previously reported multilatitude cirrus, although similar k/2 eta that decrease with height and temperature are found.

  6. Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies

    Science.gov (United States)

    Hoffmann, Lars; Hoppe, Charlotte; Müller, Rolf; Dutton, Geoffrey S.; Gille, John C.; Griessbach, Sabine; Jones, Ashley; Meyer, Catrin I.; Spang, Reinhold; Volk, C. Michael; Walker, Kaley A.

    2015-04-01

    Chlorofluorocarbons (CFCs) play a key role in stratospheric ozone loss and are strong infrared absorbers that contribute to global warming. The stratospheric lifetimes of CFCs are a measure of their stratospheric loss rates that are needed to determine global warming and ozone depletion potentials. We applied the tracer-tracer correlation approach to zonal mean climatologies from satellite measurements and model data to assess the lifetimes of CFCl3 (CFC-11) and CF2Cl2 (CFC-12). We present new estimates of the CFC-11/CFC-12 lifetime ratio and the absolute lifetime of CFC-12, based on a reference lifetime of 52 yr for CFC-11. We analyzed climatologies from three satellite missions, the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS), the HIgh Resolution Dynamics Limb Sounder (HIRDLS), and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). We found a CFC-11/CFC-12 lifetime ratio of 0.47 ± 0.08 and a CFC-12 lifetime of 112(96 - 133) yr for ACE-FTS, a ratio of 0.46 ± 0.07 and a lifetime of 113(97 - 134) yr for HIRDLS, and a ratio of 0.46 ± 0.08 and a lifetime of 114(98 - 136) yr for MIPAS. The error-weighted, combined CFC-11/CFC-12 lifetime ratio is 0.46 ± 0.04 and the CFC-12 lifetime estimate is 113(103 - 124) yr. These results are in excellent agreement with the recent Stratosphere-troposphere Processes And their Role in Climate (SPARC) reassessment, which recommends lifetimes of 52(43 - 67) yr for CFC-11 and 102(88 - 122) yr for CFC-12, respectively. Having smaller uncertainties than the results from other recent studies, our estimates can help to better constrain CFC-11 and CFC-12 lifetime recommendations in future scientific studies and assessments. Furthermore, the satellite observations were used to validate first simulation results from a new coupled model system, which integrates a Lagrangian chemistry transport model into a climate model. For the coupled EMAC/CLaMS model we found a CFC-11/CFC-12 lifetime ratio

  7. MOCHA: A three dimensional climatology of salinity and temperature of the Middle Atlantic Bight

    Science.gov (United States)

    Fleming, N. E.; Wilkin, J. L.

    2013-05-01

    A 3-D climatology of the salinity and temperature of the Middle Atlantic Bight (MAB) is developed to provide a synthesis of observations and a tool for understanding the heat and freshwater budgets, and dynamics, of this area. 150 years of historical data are quality controlled and combined by weighted least squares to a 3-D grid encompassing the Middle Atlantic Bight and the Gulf of Maine, including Chesapeake Bay, Delaware Bay, and the Hudson River Estuary. Half degree grid spacing, along with weighted fitting in horizontal distance, vertical distance, time and bathymetry provide highly resolved maps for each month of the year that compare well to independent data sets. Features such as the MAB "Cold Pool", and the seasonal cycle of heating and cooling are clearly visible throughout the months.

  8. Climatological patterns over South America derived from COSMIC radio occultation data

    Science.gov (United States)

    Hierro, R.; Llamedo, P.; de la Torre, A.; Alexander, P.; Rolla, A.

    2012-02-01

    Meteorological phenomena are closely linked to the presence of water vapor. They mainly originate and develop in the troposphere, where almost all the atmospheric water is concentrated. The Global Positioning System radio occultation (GPS RO) technique provides vertical profiles of refractivity from which other properties such as temperature and water vapor can be derived. The GPS RO capability to reproduce global, synoptic, and regional climatological patterns over South America, which is a mostly oceanic continent, is tested. From FORMOSAT-3/COSMIC mission data (2006-2010), our previous knowledge regarding global and synoptic/regional patterns of temperature, equivalent potential temperature, specific humidity, and pressure is verified. Special cases such as baroclinic disturbances arriving at South American midlatitudes and storm events over a mountain region near the Andes are analyzed. The temporal evolution and the latitude-longitude distribution in several layers of the variables listed above are well described with this technique.

  9. Mobile measurement techniques for local and micro-scale studies in urban and topo-climatology

    Directory of Open Access Journals (Sweden)

    Seidel, Jochen

    2016-03-01

    Full Text Available Technical development during the last two decades has brought new potential and new applications for ­mobile measurements. In this paper, we present six case studies where mobile measurement devices were used to acquire data for meteorological and climatological research. Three case studies deal with ground-based mobile measurements – on buses for urban climate measurements and on a vessel on a lake – and three with airborne platforms – on a cable car and on an unmanned aerial vehicle for vertical soundings and on a tethered balloon sonde for cloud physics. For each study, we describe the measurement set-up and address the potential and drawbacks of these applications. At the end, we discuss general aspects related to mobile observations especially concerning the time and space dimension of measurements.

  10. A climatological study on winds at the Kyoto University Reactor site

    International Nuclear Information System (INIS)

    A climatological study of winds at the Kyoto University Reactor (KUR) site is done by using the data from the Automated Meteorological Data Acquisition System of Japan Meteorological Agency, with a view to supporting the operations for environmental protection in case of reactor accident. At the KUR site, the land and sea breeze is appeared for one-third, a considerable part, of the year. The sea breezes from the Osaka Bay and the Kii Channel are clearly discernible, for each of which the different patterns of the diurnal variation of wind are built up at the site. For strong southerly wind experienced at the site under conditions that winds owing to synoptic pressure pattern are predominant, variable wind directions are seen in some observing stations in the Osaka plain, which is in contrast with strong westerly wind which shows a uniform flow in the Osaka plain. (author)

  11. A physical approach to air pollution climatological modelling in a complex site

    International Nuclear Information System (INIS)

    A Gaussian climatological model which takes into account physical factors affecting air pollutant dispersion, such as nocturnal radiative inversion and mixing height evolution, associated with land breeze and sea breeze regimes, respectively, has been applied to the topographically complex area of La Spezia (a basin surrounded by hilly terrain, located on the Italian coast). Results from the measurements of the dynamic and thermodynamic structure of the lower atmosphere, obtained by a series of field experiments, are utilized in the model to calculate SO2 seasonal average concentrations. The model has been tested on eight three-monthly periods by comparing the simulated values with the ones measured at the SO2 stations of the local air pollution monitoring network. Comparison of simulated and measured values was very satisfactory and proved the applicability of the implemented model for urban planning and establishment of air quality strategies also at a topographically complex site. (author)

  12. Operational planning using Climatological Observations for Maritime Prediction and Analysis Support Service (COMPASS)

    Science.gov (United States)

    O'Connor, Alison; Kirtman, Benjamin; Harrison, Scott; Gorman, Joe

    2016-05-01

    The US Navy faces several limitations when planning operations in regard to forecasting environmental conditions. Currently, mission analysis and planning tools rely heavily on short-term (less than a week) forecasts or long-term statistical climate products. However, newly available data in the form of weather forecast ensembles provides dynamical and statistical extended-range predictions that can produce more accurate predictions if ensemble members can be combined correctly. Charles River Analytics is designing the Climatological Observations for Maritime Prediction and Analysis Support Service (COMPASS), which performs data fusion over extended-range multi-model ensembles, such as the North American Multi-Model Ensemble (NMME), to produce a unified forecast for several weeks to several seasons in the future. We evaluated thirty years of forecasts using machine learning to select predictions for an all-encompassing and superior forecast that can be used to inform the Navy's decision planning process.

  13. Land surface skin temperature climatology: benefitting from the strengths of satellite observations

    International Nuclear Information System (INIS)

    Surface skin temperature observations (Tskin), as obtained by satellite remote sensing, provide useful climatological information of high spatial resolution and global coverage that enhances the traditional ground observations of surface air temperature (Tair) and so, reveal new information about land surface characteristics. This letter analyzes nine years of moderate-resolution imaging spectroradiometer (MODIS) skin temperature observations to present monthly skin temperature diurnal, seasonal, and inter-annual variations at a 0.05 deg. latitude/longitude grid over the global land surface and combines these measurements with other MODIS-based variables in an effort to understand the physical mechanisms responsible for Tskin variations. In particular, skin temperature variations are found to be closely related to vegetation cover, clouds, and water vapor, but to differ from 2 m surface Tair in terms of both physical meaning and magnitude. Therefore, the two temperatures (Tskin and Tair) are complementary in their contribution of valuable information to the study of climate change.

  14. An assessment of uncertainties and limitations in simulating tropical cyclone climatology and future changes

    Science.gov (United States)

    Suzuki-Parker, Asuka

    2011-07-01

    The recent elevated North Atlantic hurricane activity has generated considerable interests in the interaction between tropical cyclones (TCs) and climate change. The possible connection between TCs and the changing climate has been indicated by observational studies based on historical TC records; they indicate emerging trends in TC frequency and intensity in some TC basins, but the detection of trends has been hotly debated due to TC track data issues. Dynamical climate modeling has also been applied to the problem, but brings its own set of limitations owing to limited model resolution and uncertainties. The final goal of this study is to project the future changes of North Atlantic TC behavior with global warming for the next 50 years using the Nested Regional Climate Model (NRCM). Throughout the course of reaching this goal, various uncertainties and limitations in simulating TCs by the NRCM are identified and explored. First we examine the TC tracking algorithm to detect and track simulated TCs from model output. The criteria and thresholds used in the tracking algorithm control the simulated TC climatology, making it difficult to objectively assess the model's ability in simulating TC climatology. Existing tracking algorithms used by previous studies are surveyed and it is found that the criteria and thresholds are very diverse. Sensitivity of varying criteria and thresholds in TC tracking algorithm to simulated TC climatology is very high, especially with the intensity and duration thresholds. It is found that the commonly used criteria may not be strict enough to filter out intense extratropical systems and hybrid systems. We propose that a better distinction between TCs and other low-pressure systems can be achieved by adding the Cyclone Phase technique. Two sets of NRCM simulations are presented in this dissertation: One in the hindcasting mode, and the other with forcing from the Community Climate System Model (CCSM) to project into the future with

  15. Uncertainty Quantification for a Climatology of the Frequency and Spatial Distribution of North Atlantic Tropical Cyclone Landfalls

    Science.gov (United States)

    Tolwinski-Ward, S. E.; Stransky, S. M.

    2014-12-01

    We develop a Bayesian hierarchical model for the climatological frequency of Atlantic Basin tropical cyclone (TC) landfalls along the coast of North and Central America. The model is explicitly spatial, with a covariance structure that incorporates the effects of coastline geometry, and is resolved at impacts-relevant, 50-mile coastal increments. The model is based on a negative binomial regression on the phase of the Southern Oscillation, North Atlantic Oscillation, and the Atlantic Multidecadal Oscillation, and also accounts explicitly for the time-dependent uncertainty in the historical data used to fit it. The statistically-inferred climatology is interpreted in terms of current scientific understanding of the mechanisms through which related large-scale climatic variability affects the development and motion of Atlantic tropical cyclones. We also probe the spatial posterior probability distribution to quantify and rank the uncertainty in the climatology of TC landfalls that can be attributed to climatic variability, model parameter uncertainty, uncertainty in the historical landfall positions, a possible undercount bias early in the historical record, and sampling variability from the finite length of the observations. Given more detailed, expert information about uncertainty for each specific storm in the historical dataset, the model could be used to develop a definitive TC landfall climatology. It could also be used in conjunction with spatial information about exposures for risk management applications.

  16. Excess science accommodation capabilities and excess performance capabilities assessment for Mars Geoscience and Climatology Orbiter: Extended study

    Science.gov (United States)

    Clark, K.; Flacco, A.; Kaskiewicz, P.; Lebsock, K.

    1983-01-01

    The excess science accommodation and excess performance capabilities of a candidate spacecraft bus for the Mars Geoscience and Climatology Orbiter MGCO mission are assessed. The appendices are included to support the conclusions obtained during this contract extension. The appendices address the mission analysis, the attitude determination and control, the propulsion subsystem, and the spacecraft configuration.

  17. Global two-channel AVHRR aerosol climatology: effects of stratospheric aerosols and preliminary comparisons with MODIS and MISR retrievals

    Energy Technology Data Exchange (ETDEWEB)

    Geogdzhayev, Igor V. [Department of Applied Physics and Applied Mathematics, Columbia University, 2880 Broadway, New York, NY 10025 (United States); NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States); Mishchenko, Michael I. [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States)]. E-mail: crmim@giss.nasa.gov; Liu Li [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States); Department of Earth and Environmental Sciences, Columbia University, 2880 Broadway, New York, NY 10025 (United States); Remer, Lorraine [NASA Goddard Space Flight Center, Code 913, Greenbelt, MD 20771 (United States)

    2004-10-15

    We present an update on the status of the global climatology of the aerosol column optical thickness and Angstrom exponent derived from channel-1 and -2 radiances of the Advanced Very High Resolution Radiometer (AVHRR) in the framework of the Global Aerosol Climatology Project (GACP). The latest version of the climatology covers the period from July 1983 to September 2001 and is based on an adjusted value of the diffuse component of the ocean reflectance as derived from extensive comparisons with ship sun-photometer data. We use the updated GACP climatology and Stratospheric Aerosol and Gas Experiment (SAGE) data to analyze how stratospheric aerosols from major volcanic eruptions can affect the GACP aerosol product. One possible retrieval strategy based on the AVHRR channel-1 and -2 data alone is to infer both the stratospheric and the tropospheric aerosol optical thickness while assuming fixed microphysical models for both aerosol components. The second approach is to use the SAGE stratospheric aerosol data in order to constrain the AVHRR retrieval algorithm. We demonstrate that the second approach yields a consistent long-term record of the tropospheric aerosol optical thickness and Angstrom exponent. Preliminary comparisons of the GACP aerosol product with MODerate resolution Imaging Spectrometer (MODIS) and Multiangle Imaging Spectro-Radiometer aerosol retrievals show reasonable agreement, the GACP global monthly optical thickness being lower than the MODIS one by approximately 0.03. Larger differences are observed on a regional scale. Comparisons of the GACP and MODIS Angstrom exponent records are less conclusive and require further analysis.

  18. SPARC Data Initiative: A comparison of ozone climatologies from international satellite limb sounders

    Science.gov (United States)

    Tegtmeier, S.; Hegglin, M. I.; Anderson, J.; Bourassa, A.; Brohede, S.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A.; Kasai, Y.; Krüger, K.; Kyrölä, E.; Lingenfelser, G.; Lumpe, J.; Nardi, B.; Neu, J.; Pendlebury, D.; Remsberg, E.; Rozanov, A.; Smith, L.; Toohey, M.; Urban, J.; Clarmann, T.; Walker, K. A.; Wang, R. H. J.

    2013-11-01

    comprehensive quality assessment of the ozone products from 18 limb-viewing satellite instruments is provided by means of a detailed intercomparison. The ozone climatologies in form of monthly zonal mean time series covering the upper troposphere to lower mesosphere are obtained from LIMS, SAGE I/II/III, UARS-MLS, HALOE, POAM II/III, SMR, OSIRIS, MIPAS, GOMOS, SCIAMACHY, ACE-FTS, ACE-MAESTRO, Aura-MLS, HIRDLS, and SMILES within 1978-2010. The intercomparisons focus on mean biases of annual zonal mean fields, interannual variability, and seasonal cycles. Additionally, the physical consistency of the data is tested through diagnostics of the quasi-biennial oscillation and Antarctic ozone hole. The comprehensive evaluations reveal that the uncertainty in our knowledge of the atmospheric ozone mean state is smallest in the tropical and midlatitude middle stratosphere with a 1σ multi-instrument spread of less than ±5%. While the overall agreement among the climatological data sets is very good for large parts of the stratosphere, individual discrepancies have been identified, including unrealistic month-to-month fluctuations, large biases in particular atmospheric regions, or inconsistencies in the seasonal cycle. Notable differences between the data sets exist in the tropical lower stratosphere (with a spread of ±30%) and at high latitudes (±15%). In particular, large relative differences are identified in the Antarctic during the time of the ozone hole, with a spread between the monthly zonal mean fields of ±50%. The evaluations provide guidance on what data sets are the most reliable for applications such as studies of ozone variability, model-measurement comparisons, detection of long-term trends, and data-merging activities.

  19. High-resolution satellite-gauge merged precipitation climatologies of the Tropical Andes

    Science.gov (United States)

    Manz, Bastian; Buytaert, Wouter; Zulkafli, Zed; Lavado, Waldo; Willems, Bram; Robles, Luis Alberto; Rodríguez-Sánchez, Juan-Pablo

    2016-02-01

    Satellite precipitation products are becoming increasingly useful to complement rain gauge networks in regions where these are too sparse to capture spatial precipitation patterns, such as in the Tropical Andes. The Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (TPR) was active for 17 years (1998-2014) and has generated one of the longest single-sensor, high-resolution, and high-accuracy rainfall records. In this study, high-resolution (5 km) gridded mean monthly climatological precipitation is derived from the raw orbital TPR data (TRMM 2A25) and merged with 723 rain gauges using multiple satellite-gauge (S-G) merging approaches. The resulting precipitation products are evaluated by cross validation and catchment water balances (runoff ratios) for 50 catchments across the Tropical Andes. Results show that the TPR captures major synoptic and seasonal precipitation patterns and also accurately defines orographic gradients but underestimates absolute monthly rainfall rates. The S-G merged products presented in this study constitute an improved source of climatological rainfall data, outperforming the gridded TPR product as well as a rain gauge-only product based on ordinary Kriging. Among the S-G merging methods, performance of inverse distance interpolation of satellite-gauge residuals was similar to that of geostatistical methods, which were more sensitive to gauge network density. High uncertainty and low performance of the merged precipitation products predominantly affected regions with low and intermittent precipitation regimes (e.g., Peruvian Pacific coast) and is likely linked to the low TPR sampling frequency. All S-G merged products presented in this study are available in the public domain.

  20. A dynamically downscaled climatology of severe convective thunderstorms over the United States

    Science.gov (United States)

    Robinson, Eric D.

    Severe convective storms---and the tornadoes, hail, and damaging winds that they produce---represent a real risk to life and property in the United States. In 2011, tornadoes claimed over 540 lives over 15 different states, the fourth highest toll on record. It is not known whether 2011 represents a positive trend in the frequency of severe thunderstorms and associated phenomena because of the many uncertainties in the historical record. This study seeks to examine a method developed to study these severe phenomena using a high-resolution numerical weather prediction model driven by large-scale reanalysis and employing an artificial neural network. Specifically, high resolution simulations of the Weather Research and Forecasting model, forced by data from the NCEP/NCAR Reanalysis Project are used to generate daily re-forecasts of every day in April, May, and June over 1990--2009. These simulations are examined at hourly intervals for the presence of severe convection through the use of an artificial neural network that was trained using days from ten years of modeled data that coincided with observed days of severe weather. This network is applied over all twenty years of data in order to examine the modeled trends in severe phenomena. Tests are also performed to examine the sensitivity of the modeling procedure to various parameters including integration time, land surface heterogeneity, and model physics. Results indicate that, contrary to the biased observational record, there has been no statistically significant change in the frequency of warm season severe weather occurrences in the eastern two-thirds of the United States over 1990--2009. Further, sensitivity tests indicate an approach with more frequent re-initializations of the model produces a more physically realistic climatology of severe convective events, and that this climatology is fairly insensitive to small changes in the land surface and model physics. A similar result is found for the spatial

  1. Weather patterns and hydro-climatological precursors of extreme floods in Switzerland since 1868

    Directory of Open Access Journals (Sweden)

    Peter Stucki

    2012-12-01

    Full Text Available The generation of 24 extreme floods in large catchments of the central Alps is analyzed from instrumental and documentary data, newly digitized observations of precipitation (DigiHom and 20th Century Reanalysis (20CR data. Extreme floods are determined by the 95th percentile of differences between an annual flood and a defined contemporary flood. For a selection of six events between 1868 and 1910, we describe preconditioning elements such as precipitation, temperature, and snow cover anomalies. Specific weather patterns are assessed through a subjective analysis of three-dimensional atmospheric circulation. A focus is placed on synoptic-scale features including mid-tropospheric ascent, low-level moisture transport, propagation of cyclones, and temperature anomalies. We propose a hydro-meteorological classification of all 24 investigated events according to flood-generating weather conditions. Key elements of the upper-level synoptic-scale flow are summarized by five types: (i pivoting cut-off lows, (ii elongated cut-off lows, (iii elongated troughs, (iv waves (with a kink, and (v approximately zonal flow over the Alpine region. We found that the most extreme floods (as above, but ≥ 98th percentile in Switzerland since 1868 were caused by the interaction of severe hydro-climatologic conditions with a flood-inducing weather situation. The 20CR data provide plausible synoptic-scale meteorological patterns leading to heavy precipitation. The proposed catalogue of weather patterns and hydro-climatologic precursors can give direction when anticipating the possibility of severe floods in the Alpine region.

  2. Weather patterns and hydro-climatological precursors of extreme floods in Switzerland since 1868

    International Nuclear Information System (INIS)

    The generation of 24 extreme floods in large catchments of the central Alps is analyzed from instrumental and documentary data, newly digitized observations of precipitation (DigiHom) and 20th Century Reanalysis (20CR) data. Extreme floods are determined by the 95th percentile of differences between an annual flood and a defined contemporary flood. For a selection of six events between 1868 and 1910, we describe preconditioning elements such as precipitation, temperature, and snow cover anomalies. Specific weather patterns are assessed through a subjective analysis of three-dimensional atmospheric circulation. A focus is placed on synoptic-scale features including mid-tropospheric ascent, low-level moisture transport, propagation of cyclones, and temperature anomalies. We propose a hydro-meteorological classification of all 24 investigated events according to flood-generating weather conditions. Key elements of the upper-level synoptic-scale flow are summarized by five types: (i) pivoting cut-off lows, (ii) elongated cut-off lows, (iii) elongated troughs, (iv) waves (with a kink), and (v) approximately zonal flow over the Alpine region. We found that the most extreme floods (as above, but ≥ 98th percentile) in Switzerland since 1868 were caused by the interaction of severe hydro-climatologic conditions with a flood-inducing weather situation. The 20CR data provide plausible synoptic-scale meteorological patterns leading to heavy precipitation. The proposed catalogue of weather patterns and hydro-climatologic precursors can give direction when anticipating the possibility of severe floods in the Alpine region. (orig.)

  3. Climatology and dynamics of summer tropopause folds over the eastern Mediterranean and the Middle East

    Science.gov (United States)

    Tyrlis, E.; Skerlak, B.; Sprenger, M.; Wernli, H.; Zittis, G.; Lelieveld, J.

    2013-12-01

    A climatology of tropopause folds is presented that focus on the summer events occurring over the Eastern Mediterranean and the Middle East (EMME) based on the ERA-Interim dataset. The methodology employs an algorithm that detects folds as areas featuring multiple crossings of the dynamical tropopause and allows their classification according to their vertical extent. Our results confirm the findings of an earlier 1-year climatology that recognized a global ';hot spot' of fold activity over a sector extending from the eastern Mediterranean to Afghanistan, in the vicinity of the subtropical jet. Two distinct maxima of activity are recognized over Turkey and Iran-Afghanistan where fold occurrence exceeds 25%. Rarely, deep folds form over the Levantine Basin and Iran at surprising low latitudes. This summertime increase in fold activity defies the zonal mean seasonal cycle over the subtropics and it is driven by the South Asian Monsoon. From late spring, the EMME is gradually brought under the influence of the zonally asymmetric background state induced by the monsoon, which features an elevated tropopause and depression of isentropic surfaces. As areas of sharply sloping isentropes develop especially over the eastern Mediterranean and Iran-Afghanistan, subsidence and fold formation are favored. The monsoon also drives the interannual variability of EMME fold activity. An upward trend in fold activity is identified, especially during May that can be attributed to the recent advanced monsoon onset and the deeper convective activity throughout summer. This stronger upper level monsoon signature promotes enhanced upper level baroclinicity over the EMME that favors folding.

  4. A new approach to sensitivity climatologies: the DTS-MEDEX-2009 campaign

    Directory of Open Access Journals (Sweden)

    A. Jansa

    2011-09-01

    Full Text Available Adaptive observation is an approach to improving the quality of numerical weather forecasts through the optimization of observing networks. It is sometimes referred to as Data Targeting (DT. This approach has been applied to high impact weather during specific field campaigns in the past decade. Adaptive observations may involve various types of observations, including either specific research observing platforms or routine observing platforms employed in an adaptive way. The North-Atlantic TReC 2003 and the EURORISK-PREVIEW 2008 exercises focused on the North-Atlantic and Western Europe areas using mainly routine observing systems. These campaigns also included Mediterranean cases.

    The most recent campaign, DTS-MEDEX-2009, is the first campaign in which the DT method has been used to address exclusively Mediterranean high impact weather events. In this campaign, which is an important stage in the MEDEX development, only operational radiosonde stations and commercial aircraft data (AMDAR have provided additional observations. Although specific diagnostic studies are needed to assess the impact of the extra-observations on forecast skill and demonstrate the effectiveness of DTS-MEDEX-2009, some preliminary findings can be deduced from a survey of this targeting exercise.

    After a description of the data targeting system and some illustrations of particular cases, this paper attempts some comparisons of additional observation needs (through effectively deployed radio-soundings with sensitivity climatologies in the Mediterranean. The first step towards a sensitivity climatology for Mediterranean cases of high impact weather is indirectly given by the frequency of extra-soundings launched from the network of radiosonde stations involved in the DTS-MEDEX-2009 campaign.

  5. A spatial climatology of precipitation from North Atlantic tropical cyclones over the Eastern United States

    Science.gov (United States)

    Zhou, Y.

    2015-12-01

    The precipitation associated with tropical cyclones (TCs) over the eastern U.S has drawn significant attention from researchers. Among studies about tropical cyclone precipitation (TCP), separating rainfall into tropical and non-tropical cyclone components is a challenging task. Therefore, a need exists for continued spatial climatological analysis of rainfall associated of TCs. To provide a long-term climatology of TCP in this study, 305 TCs having tracks located within 500 km of the U.S. coastline from 1948-2012 are examined. The daily precipitation amounts on 0.25°× 0.25° latitude-longitude grids are from the Climate Prediction Center (CPC) Unified Precipitation Data (UPD). A GIS and Python based method is developed to identify rainfall swaths produced by TCs. Then we overlay all TCP swaths on a U.S. county map to get cumulative frequency of counties receiving rainfall from a TC with value greater than 25.4 mm. We find that there are 2533 counties in 25 states had been affected by TCP with value greater than 25.4 mm at least once during 1948 to 2012. The total area of TCP and TCP area averaged by annual TC counts and days shows significant increases after the 1990s. By comparing the rainfall swaths to the wind swaths as reported by previous work, we determine the frequency with which locations receive either condition produced by TCs. The results reveal that TCPs extend more inland and have more frequency than TC winds, since TC winds decays quickly after make landfall, while rainfall field may expand due to extra-tropical transition or land surface conditions.

  6. Influence of climatological and meteorological events on the Cuban environmental gamma background

    International Nuclear Information System (INIS)

    Full text: A network of environmental radiological surveillance can appropriately respond in case of any radiological anomaly, due to the suitable methodology employed, the equipment used, the automatized detection systems and the data processing. But it is also important to know how the measurements of the different radiological indicators vary with the action of any atmospheric phenomenon. In this work, an analysis of the effects produced on the environmental gamma background in Cuba when acting climatological and meteorological events, has been achieved. Events, such as seasons of severe precipitation, dry seasons, winter and summer, hurricanes and high and low pressures are studied. The measurements were carried out with a gamma probe which is equipped with two Geiger Muller detectors and a temperature sensor. This probe is located at the height of 3.5 m and is exposed to the direct sun rays. We have built hypothesis for explaining some behaviors related to meteorological events, such as hurricanes. However, our theories are not conclusive, since the data obtained from the presence of this kind of phenomena next to the sites of interest was very poor. In this work, we have given explanation to the fluctuation of the measurements achieved of the environmental gamma background, based on the occurrence of some meteorological and climatological events. All this was possible due to a previous study about the influence of the diurnal variation of the temperature over the measurements of the gamma dose rate. On the other hand, the results obtained and the study of the influence of another environmental parameters, will contribute to the alarm levels setting for this radiological indicator according to the season which the measurements are achieved in. (author)

  7. Generation of a Bending Angle Radio Occultation Climatology (BAROCLIM and its use in radio occultation retrievals

    Directory of Open Access Journals (Sweden)

    B. Scherllin-Pirscher

    2014-08-01

    Full Text Available In this paper, we introduce a bending angle radio occultation climatology (BAROCLIM based on Formosat-3/COSMIC (F3C data. This climatology represents the monthly-mean atmospheric state from 2006 to 2012. Bending angles from radio occultation (RO measurements are obtained from the accumulation of the change in the raypath direction of Global Positioning System (GPS signals. Best quality of these near-vertical profiles is found from the middle troposphere up to the mesosphere. Beside RO bending angles we also use data from the Mass Spectrometer and Incoherent Scatter Radar (MSIS model to expand BAROCLIM in a spectral model, which (theoretically reaches from the surface up to infinity. Due to the very high quality of BAROCLIM up to the mesosphere, it can be used to detect deficiencies in current state-of-the-art analysis and reanalysis products from numerical weather prediction (NWP centers. For bending angles derived from European Centre for Medium-Range Weather Forecasts (ECMWF analysis fields from 2006 to 2012, e.g., we find a positive bias of 0.5% to % at 40 km, which increases to more than 2% at 50 km. BAROCLIM can also be used as a priori information in RO profile retrievals. In contrast to other a priori information (i.e., MSIS we find that the use of BAROCLIM better preserves the mean of raw RO measurements. Global statistics of statistically optimized bending angle and refractivity profiles also confirm that BAROCLIM outperforms MSIS. These results clearly demonstrate the utility of BAROCLIM.

  8. The SHADOZ Data Base: History, Archive Web Guide, and Sample Climatologies

    Science.gov (United States)

    White, J. C.; Thompson, A. M.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    SHADOZ (Southern Hemisphere Additional Ozonesonde) is a project to augment and archive ozonesonde data from ten tropical and subtropical ozone stations. Started in 1998 by NASA's Goddard Space Flight Center and other US and international co-investigators, SHADOZ is an important tool for tropospheric ozone research in the equatorial region. The rationale for SHADOZ is to: (1) validate and improve remote sensing techniques (e.g., the Total Ozone Mapping Spectrometer (TOMS) satellite) for estimating tropical ozone, (2) contribute to climatology and trend analyses of tropical ozone and (3) provide research topics to scientists and educate students, especially in participating countries. SHADOZ is envisioned as a data service to the global scientific community by providing a central public archive location via the internet: http://code9l6.gsfc.nasa.gov/Data_services/shadoz. While the SHADOZ website maintains a standard data format for the archive, it also informs the data users on the differing stations' preparation techniques and data treatment. The presentation navigates through the SHADOZ website to access each station's sounding data and summarize each station's characteristics. Since the start of the project in 1998, the SHADOZ archive has accumulated over 600 ozonesonde profiles and received over 30,000 outside data requests. Data also includes launches from various SHADOZ supported field campaigns, such as, the Indian Ocean Experiment (INDOEX), Sounding of Ozone and Water in the Equatorial Region (SOWER) and Aerosols99 Atlantic Cruise. Using data from the archive, sample climatologies and profiles from selected stations and campaigns will be shown.

  9. CLIMATOLOGICAL CHARACTERISTICS OF WINTER IN BUCIN MOUNTAIN TOP (GURGHIU MOUNTAINS, EASTERN CARPATHIANS

    Directory of Open Access Journals (Sweden)

    O. RUSZ

    2013-03-01

    Full Text Available In order to study the features of winter in Bucin Mountaintop, data collected from Bucin meteorological station (1270 m were used. The Bucin mountaintop is situated in the central part of Gurghiu Mountains and it is a popular touristic destination. Several climatological parameters of the the cold months (November, December, January, February, March, April in the period 1978-2010 were studied: mean temperatures, snow depth, snow cover, number of days with solid precipitation, etc. The mean temperature of these months is between -5.8°C (January and 3.1°C (April. The absolute minimum temperature (-26.1°C since the Bucin weather station functions (from 1978 was registered in February 1985 (in case of nearly mountain depressions this value approached -40°C. Generally, durable snow cover is present from November to April and on average 150 days/year are covered by snow. The highest mean snow depth is registered in March (76 cm. According to the Köppen asymmetric index the number of years that have lower snow depth that average is higher in case of all months. Mean number of frosty days (annual count of days when Tmin < 0°C is 161, of extremely cold days (annual count of days when Tmin< -10°C is 44 and of winter days (annual count of days when Tmax < 0°C is 75. Correlation tests (Pearson show statistically significant values in case of snow depth and mean temperature for almost all months, but in January and February, there are no statistically significant correlations between snow depth and precipitation amounts respectively number of days with solid precipitation. Generally, there are no statistically significant trends (Mann-Kendall tests regarding these climatological parameters typical for winter.

  10. A proposal for a worldwide definition of health resort medicine, balneology, medical hydrology and climatology

    Science.gov (United States)

    Gutenbrunner, Christoph; Bender, Tamas; Cantista, Pedro; Karagülle, Zeki

    2010-09-01

    Health Resort Medicine, Balneology, Medical Hydrology and Climatology are not fully recognised as independent medical specialties at a global international level. Analysing the reasons, we can identify both external (from outside the field) and internal (from inside the field) factors. External arguments include, e.g. the lack of scientific evidence, the fact that Balneotherapy and Climatotherapy is not used in all countries, and the fact that Health Resort Medicine, Balneology, Medical Hydrology and Climatology focus only on single methods and do not have a comprehensive concept. Implicit barriers are the lack of international accepted terms in the field, the restriction of being allowed to practice the activities only in specific settings, and the trend to use Balneotherapy mainly for wellness concepts. Especially the implicit barriers should be subject to intense discussions among scientists and specialists. This paper suggests one option to tackle the problem of implicit barriers by making a proposal for a structure and description of the medical field, and to provide some commonly acceptable descriptions of content and terminology. The medical area can be defined as “medicine in health resorts” (or “health resort medicine”). Health resort medicine includes “all medical activities originated and derived in health resorts based on scientific evidence aiming at health promotion, prevention, therapy and rehabilitation”. Core elements of health resort interventions in health resorts are balneotherapy, hydrotherapy, and climatotherapy. Health resort medicine can be used for health promotion, prevention, treatment, and rehabilitation. The use of natural mineral waters, gases and peloids in many countries is called balneotherapy, but other (equivalent) terms exist. Substances used for balneotherapy are medical mineral waters, medical peloids, and natural gases (bathing, drinking, inhalation, etc.). The use of plain water (tap water) for therapy is called

  11. Carbon monoxide climatology derived from the trajectory mapping of global MOZAIC-IAGOS data

    Directory of Open Access Journals (Sweden)

    M. Osman

    2015-11-01

    Full Text Available A three-dimensional gridded climatology of carbon monoxide (CO has been developed by trajectory mapping of global MOZAIC-IAGOS in situ measurements from commercial aircraft data. CO measurements made during aircraft ascent and descent, comprising nearly 41 200 profiles at 148 airports worldwide from December 2001 to December 2012 are used. Forward and backward trajectories are calculated from meteorological reanalysis data in order to map the CO measurements to other locations, and so to fill in the spatial domain. This domain-filling technique employs 15 800 000 calculated trajectories to map otherwise sparse MOZAIC-IAGOS data into a quasi-global field. The resulting trajectory-mapped CO dataset is archived monthly from 2001–2012 on a grid of 5° longitude × 5° latitude × 1 km altitude, from the surface to 14 km altitude. The mapping product has been carefully evaluated, by comparing maps constructed using only forward trajectories and using only backward trajectories. The two methods show similar global CO distribution patterns. The magnitude of their differences is most commonly 10 % or less, and found to be less than 30 % for almost all cases. The trajectory-mapped CO dataset has also been validated by comparison profiles for individual airports with those produced by the mapping method when data from that site are excluded. While there are larger differences below 2 km, the two methods agree very well between 2 and 10 km with the magnitude of biases within 20 %. Maps are also compared with Version 6 data from the Measurements Of Pollution In The Troposphere (MOPITT satellite instrument. While agreement is good in the lowermost troposphere, the MOPITT CO profile shows negative biases of ~ 20 % between 500 and 300 hPa. These upper troposphere biases are not related to the mapping procedure, as almost identical differences are found with the original in situ MOZAIC-IAGOS data. The total CO trajectory-mapped MOZAIC-IAGOS climatology column

  12. Carbon monoxide climatology derived from the trajectory mapping of global MOZAIC-IAGOS data

    Science.gov (United States)

    Osman, M.; Tarasick, D. W.; Liu, J.; Moeini, O.; Thouret, V.; Fioletov, V. E.; Parrington, M.; Nédélec, P.

    2015-11-01

    A three-dimensional gridded climatology of carbon monoxide (CO) has been developed by trajectory mapping of global MOZAIC-IAGOS in situ measurements from commercial aircraft data. CO measurements made during aircraft ascent and descent, comprising nearly 41 200 profiles at 148 airports worldwide from December 2001 to December 2012 are used. Forward and backward trajectories are calculated from meteorological reanalysis data in order to map the CO measurements to other locations, and so to fill in the spatial domain. This domain-filling technique employs 15 800 000 calculated trajectories to map otherwise sparse MOZAIC-IAGOS data into a quasi-global field. The resulting trajectory-mapped CO dataset is archived monthly from 2001-2012 on a grid of 5° longitude × 5° latitude × 1 km altitude, from the surface to 14 km altitude. The mapping product has been carefully evaluated, by comparing maps constructed using only forward trajectories and using only backward trajectories. The two methods show similar global CO distribution patterns. The magnitude of their differences is most commonly 10 % or less, and found to be less than 30 % for almost all cases. The trajectory-mapped CO dataset has also been validated by comparison profiles for individual airports with those produced by the mapping method when data from that site are excluded. While there are larger differences below 2 km, the two methods agree very well between 2 and 10 km with the magnitude of biases within 20 %. Maps are also compared with Version 6 data from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. While agreement is good in the lowermost troposphere, the MOPITT CO profile shows negative biases of ~ 20 % between 500 and 300 hPa. These upper troposphere biases are not related to the mapping procedure, as almost identical differences are found with the original in situ MOZAIC-IAGOS data. The total CO trajectory-mapped MOZAIC-IAGOS climatology column agrees with the

  13. Quantifying the climatological cloud-free direct radiative forcing of aerosol over the Red Sea

    KAUST Repository

    Brindley, Helen

    2015-04-01

    A combination of ground-based and satellite observations are used, in conjunction with column radiative transfer modelling, to assess the climatological aerosol loading and quantify its corresponding cloud-free direct radiative forcing (DRF) over the Red Sea. While there have been campaigns designed to probe aerosol-climate interactions over much of the world, relatively little attention has been paid to this region. Because of the remoteness of the area, satellite retrievals provide a crucial tool for assessing aerosol loading over the Sea. However, agreement between aerosol properties inferred from measurements from different instruments, and even in some cases from the same measurements using different retrieval algorithms can be poor, particularly in the case of mineral dust. Ground based measurements which can be used to evaluate retrievals are thus highly desirable. Here we take advantage of ship-based sun-photometer micro-tops observations gathered from a series of cruises which took place across the Red Sea during 2011 and 2013. To our knowledge these data represent the first set of detailed aerosol measurements from the Sea. They thus provide a unique opportunity to assess the performance of satellite retrieval algorithms in this region. Initially two aerosol optical depth (AOD) retrieval algorithms developed for the MODerate Resolution Imaging Spectroradiometer (MODIS) and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instruments are evaluated via comparison with the co-located cruise observations. These show excellent agreement, with correlations typically better than 0.9 and very small root-mean-square and bias differences. Calculations of radiative fluxes and DRF along one of the cruises using the observed aerosol and meteorological conditions also show good agreement with co-located estimates from the Geostationary Earth Radiation Budget (GERB) instrument if the aerosol asymmetry parameter is adjusted to account for the presence of large

  14. The use of normalized climatological anomalies to rank synoptic-scale events and their relation to Weather Types

    Science.gov (United States)

    Ramos, A. M.; Lorenzo, M. N.; Gimeno, L.; Nieto, R.; Añel, J. A.

    2009-09-01

    Several methods have been developed to rank meteorological events in terms of severity, social impact or economic impacts. These classifications are not always objective since they depend of several factors, for instance, the observation network is biased towards the densely populated urban areas against rural or oceanic areas. It is also very important to note that not all rare synoptic-scale meteorological events attract significant media attention. In this work we use a comprehensive method of classifying synoptic-scale events adapted from Hart and Grumm, 2001, to the European region (30N-60N, 30W-15E). The main motivation behind this method is that the more unusual the event (a cold outbreak, a heat wave, or a flood), for a given region, the higher ranked it must be. To do so, we use four basic meteorological variables (Height, Temperature, Wind and Specific Humidity) from NCEP reanalysis dataset over the range of 1000hPa to 200hPa at a daily basis from 1948 to 2004. The climatology used embraces the 1961-1990 period. For each variable, the analysis of raking climatological anomalies was computed taking into account the daily normalized departure from climatology at different levels. For each day (from 1948 to 2004) we have four anomaly measures, one for each variable, and another, a combined where the anomaly (total anomaly) is the average of the anomaly of the four variables. Results will be analyzed on a monthly, seasonal and annual basis. Seasonal trends and variability will also be shown. In addition, and given the extent of the database, the expected return periods associated with the anomalies are revealed. Moreover, we also use an automated version of the Lamb weather type (WT) classification scheme (Jones et al, 1993) adapted for the Galicia area (Northwestern corner of the Iberian Peninsula) by Lorenzo et al (2008) in order to compute the daily local circulation regimes in this area. By combining the corresponding daily WT with the five anomaly

  15. Distribution functions and statistical parameters that may be used to characterize limb sounders gravity wave climatologies in the stratosphere

    Science.gov (United States)

    Alexander, P.; Luna, D.; de la Torre, A.; Schmidt, T.

    2015-08-01

    The number of gravity wave (GW) activity climatologies in the stratosphere started to increase more than 10 years ago since the appearance of large amounts of limb and nadir satellite sounders data. There have been very few discussions regarding the adequate statistical description of GW activity in terms of a distribution function and its parameters. We put forward the question whether a general statistical functional representation adaptable to the characteristics of GW activity in diverse geographic regions and seasons exists. Here we approach this issue for two different types of limb sounders and in particular we try to find out which parameters may represent at best the climatological features. We study results for a region close to the Patagonian Andes and their prolongation in the Antarctic Peninsula, which is well-known for the generation by topography of intense stratospheric GW, specially during winter and spring. Global Positioning System (GPS) radio occultation (RO) records presently provide over 2000 profiles per day. We used 5 years of COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) mission GPS RO data, which supplied almost 150,000 retrievals for our study. Three different distribution functions have been approached to describe the GW activity climatologies: gaussian, log-normal and gamma. The latter function has not been used in previous work. It has been shown here that it is a competitive option to the log-normal distribution. In addition, its use allows not only to quantify the GW activity level of each climatology in the stratosphere, but also to find out the number of significant modes that essentially determine it. Alternative parameters to the mean like the median may be used to characterize the climatologies. The use of the median may exhibit advantages in cases where the presence of spurious large GW activity measurements are suspected in GPS RO data. The mean is equally suitable to establish GW activity

  16. Innovative aspects for teaching the Geology and Climatology course in Agricultural and Forestry Engineering degrees

    Science.gov (United States)

    del Campillo, M. C.; Cañasveras, J. C.; Sánchez-Alcalá, I.; Sánchez-Rodríguez, A. R.; Alburquerque, J. A.; Castro, M. A.; Rey, M. A.; Barrón, V.; Torrent, J.

    2012-04-01

    Courses of the first year at Engineering are typically basic to understanding other subjects and in many cases less attractive for students. In order to innovate and incorporate some aims of the Bologna process, here we present the development of the course of Geology and Climatology given the first year of Agricultural and Forestry degrees at the University of Córdoba. Temporal distribution of activities was as follows: a) to the whole group: 35% of master class, 5% of conferences and 10% of field trip, b) to the medium group (performance of a professional work: characterization of the geology and climatology of an area that will need to know for the courses in the coming years (for example soil science, crop sciences and environmental sciences). Students have to a) complete a literature review of all work done to date, b) use and study the geological map (1:50000) published by the Geological Survey of Spain (IGME), visit the study area in which they had to pick up rocks and subsequently to characterize them, and c) obtain meteorological data from the Spanish Agency of Meteorology (AEMET) (minimum 30 years of precipitation, 15 years of temperatures and 10 years of other variables) for a complete characterization of the climate. The assessment system for students included: attend classes, participation in practicals and excursions, carry out exercices, oral presentation of the report and a final written test. Key factors that favored student participation and interest in the course were: a) the small number of students in classes dedicated to the practicals and seminars and the continuous advice from teachers, and b) the personal choice by the student of the work area, usually close to their origin and in many cases from family property. All of this has served to students, who are involved with more dedication to the course, to solve specific problems and close to critical thinking, have contact with the real problems (in accessing the necessary data

  17. A convection climatology of the inner alpine region based on radar and lightning data

    Science.gov (United States)

    Meyer, Vera; Tüchler, Lukas; Tollardo, Mauro; Cenzon, Giovanni; Domenichini, Francesco

    2014-05-01

    A convection climatology of the inner alpine region covering Western Austria and North Italy is generated from five years radar and lightning data. The Austrian thunderstorm nowcasting tool (A-TNT) is employed to identify and track convective cells based on a uniform MaxCAPPI composite and lightning intensity maps following the method of the thunderstorm tracking and nowcasting algorithm ec-TRAM [1]. The algorithm identifies and monitors regions of intense precipitation and lightning activity separately by analyzing sequential two-dimensional intensity maps of radar precipitation rates and lightning densities, respectively. Each data source is processed by a stand-alone identification and tracking procedure, where the two separate tracking results are combined to comprehensive "convective cells" in a subsequent, final step. With this approach lightning data is used as a second, independent and complementing data source to improve storm identification and tracking in those regions where radar data is not or poorly available and to compensate for occasional data failures. Furthermore, pure convective precipitation can be distinguished from thunderstorms which also exhibit electrical activity. Intensive precipitation cells are identified based on the uniform radar MaxCAPPI composite of the core region which is generated at ZAMG on a 1 km X 1 km basic grid. Lightning data are provided by the European lightning detection network EUCLID (www.euclid.org). A-TNT is run with a temporal resolution of 5 minutes. First results of the convection climatology will be presented. Regions of preferred storm initiation and dissipation are investigated with respect to diurnal and seasonal aspects as well as different storm classes. Due to the rather short data archive the work focus on the documentation of the current situation. The presented work is performed within the framework of the INTERREG IV project 'Past, Present and Perspective Climate of Tirol, South Tyrol-Alto Adige and

  18. Climatological Data Rescue from historic meteorological stations in the Czech Republic.

    Science.gov (United States)

    Repka, M.

    2010-09-01

    Digitization of climatological data from meteorological station had several periods in past. Last period is very close connected with database system CLIDATA. The main source of historical data is archive in Ostrava regional office of CHMI where a lot of historical monthly reports of observations with daily data are stored. Other historical data were founded from various types of historical annual reports and last but not least from border cooperation with Polish and Slovak meteorological services. During several last years were imported daily data from new discovered stations, and some elements from historic stations such as precipitation, temperature, relative humidity, cloudiness, hourly data of sunshine, temperatures from thermographs and also meteorological phenomena from some synoptic stations. Within the frame of our project we could also digitize wind speed, wind direction and wind gust data. During more than 150 years of regular meteorological observation, were used a big amount of various types of monthly reports for measured data records. Meteorological stations were founded by several organizations and all of them used another kind of reports that were changed during years. We recognized nearly 30 types of precipitation monthly reports and 50 types of climatologic reports. Digitization of data especially from very historical stations brings also some problems during definition of metadata such as coordinates, elevations, measuring instruments height, a lot of observing terms or historic units of elements. Some historical annual reports mention observer's jobs, that is very interesting and we can find position of meteorological stations more exactly. Data quality control has been proceeded since 1993. First were used special programs and algorithms outside of database system. Some new programs for wrong values detection or for missing values filling are used at present. CLIDATA database system and its extensions allows to make logical and spatial data

  19. Transport of anthropogenic emissions during ARCTAS-A: a climatology and regional case studies

    Directory of Open Access Journals (Sweden)

    D. L. Harrigan

    2011-02-01

    Full Text Available The National Aeronautics and Space Administration (NASA conducted the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS mission during 2008 as a part of the International Polar Year (IPY. The purpose of ARCTAS was to study the factors responsible for changes in the Arctic's atmospheric composition and climate. A major emphasis was to investigate Arctic haze, which is most pronounced during winter and early spring. This study focuses on the spring phase of ARCTAS (ARCTAS-A that was based in Alaska during April 2008. Although anthropogenic emissions historically have been associated with Arctic haze, biomass burning dominated the ARCTAS-A period and has been the focus of many ARCTAS related studies.

    This study determines the common pathways for anthropogenic emissions during ARCTAS-A. Trajectories (air parcels are released each day from three historically significant regions of anthropogenic emissions (Asia, North America, and Europe. These fifteen day forward trajectories are calculated using data from the Weather Research and Forecasting (WRF model at 45 km horizontal resolution. The trajectories then are examined to determine: origins of emissions that reach the Arctic (defined as north of 70° N within fifteen days, pathways of the emissions reaching the Arctic, Arctic entry locations, and altitudes at which the trajectories enter the Arctic. These results serve as regional "climatologies" for the ARCTAS-A period.

    Three cases during the ARCTAS-A period (one for each of the regions above are examined using backward trajectories and chemical fingerprinting based on in situ data sampled from the NASA DC-8. The fingerprinting utilizes volatile organic compounds that represent pure anthropogenic tracers, Asian anthropogenic pollution, incomplete combustion, and natural gas emissions. We determine flight legs containing anthropogenic emissions and the pathways travelled by these emissions

  20. Global sea-to-air flux climatology for bromoform, dibromomethane and methyl iodide

    Directory of Open Access Journals (Sweden)

    F. Ziska

    2013-09-01

    Full Text Available Volatile halogenated organic compounds containing bromine and iodine, which are naturally produced in the ocean, are involved in ozone depletion in both the troposphere and stratosphere. Three prominent compounds transporting large amounts of marine halogens into the atmosphere are bromoform (CHBr3, dibromomethane (CH2Br2 and methyl iodide (CH3I. The input of marine halogens to the stratosphere has been estimated from observations and modelling studies using low-resolution oceanic emission scenarios derived from top-down approaches. In order to improve emission inventory estimates, we calculate data-based high resolution global sea-to-air flux estimates of these compounds from surface observations within the HalOcAt (Halocarbons in the Ocean and Atmosphere database (https://halocat.geomar.de/. Global maps of marine and atmospheric surface concentrations are derived from the data which are divided into coastal, shelf and open ocean regions. Considering physical and biogeochemical characteristics of ocean and atmosphere, the open ocean water and atmosphere data are classified into 21 regions. The available data are interpolated onto a 1°×1° grid while missing grid values are interpolated with latitudinal and longitudinal dependent regression techniques reflecting the compounds' distributions. With the generated surface concentration climatologies for the ocean and atmosphere, global sea-to-air concentration gradients and sea-to-air fluxes are calculated. Based on these calculations we estimate a total global flux of 1.5/2.5 Gmol Br yr−1 for CHBr3, 0.78/0.98 Gmol Br yr−1 for CH2Br2 and 1.24/1.45 Gmol Br yr−1 for CH3I (robust fit/ordinary least squares regression techniques. Contrary to recent studies, negative fluxes occur in each sea-to-air flux climatology, mainly in the Arctic and Antarctic regions. "Hot spots" for global polybromomethane emissions are located in the equatorial region, whereas methyl iodide emissions are enhanced in the

  1. Global sea-to-air flux climatology for bromoform, dibromomethane and methyl iodide

    Directory of Open Access Journals (Sweden)

    F. Ziska

    2013-02-01

    Full Text Available Volatile halogenated organic compounds containing bromine and iodine, which are naturally produced in the ocean, are involved in ozone depletion in both the troposphere and stratosphere. Three prominent compounds transporting large amounts of marine halogens into the atmosphere are bromoform (CHBr3, dibromomethane (CH2Br2 and methyl iodide (CH3I. The input of marine halogens to the stratosphere is based on observations and modeling studies using low resolution oceanic emission scenarios derived from top down approaches. In order to improve emission inventory estimates, we calculate data-based high resolution global sea-to-air flux estimates of these compounds from surface observations within the HalOcAt database (https://halocat.geomar.de/. Global maps of marine and atmospheric surface concentrations are derived from the data which are divided into coastal, shelf and open ocean regions. Considering physical and biogeochemical characteristics of ocean and atmosphere, the open ocean water and atmosphere data are classified into 21 regions. The available data are interpolated onto a 1° × 1° grid while missing grid values are interpolated with latitudinal and longitudinal dependent regression techniques reflecting the compounds' distributions. With the generated surface concentration climatologies for the ocean and atmosphere, global concentration gradients and sea-to-air fluxes are calculated. Based on these calculations we estimate a total global flux of 1.5/2.5 Gmol Br yr−1 for CHBr3, 0.78/0.98 Gmol Br yr−1 for CH2Br2 and 1.24/1.45 Gmol I yr−1 for CH3I (Robust Fit/Ordinary Least Square regression technique. Contrary to recent studies, negative fluxes occur in each sea-to-air flux climatology, mainly in the Arctic and Antarctic region. "Hot spots" for global

  2. Surface Wind Observational Database in North Eastern North America: Quality Control Procedure and Climatological Variability

    Science.gov (United States)

    Lucio-Eceiza, Etor E.; Fidel González-Rouco, J.; Navarro, Jorge; Hidalgo, Ángela; Conte, Jorge; Beltrami, Hugo

    2015-04-01

    This work summarizes the design and application of a Quality Control (QC) procedure for an observational surface wind database located in North Eastern North America. It also presents some insights of the long-term climatological variability over the region. The database consists of 527 sites (487 land stations and 40 buoys) with varying resolutions of hourly, 3 hourly and 6 hourly data, compiled from three different source institutions. The records span from 1940 to 2010 and cover an approximate spatial extension of 2.2 × 106 km2. The QC process is composed of different phases focused either on problems related with the providing source institutions or measurement errors. Due to the size of the data set, a great effort has been made on the automation of the procedures. A number of problems are associated with data management and data conventions: unification of measurement units and recording times due to the variety of institutional sources; detection of erroneous data sequence duplications within a station or among different ones; and detection of errors related with physically unrealistic data measurements. From the other hand there is a variety of treated instrumental errors: problems related with low variability, placing particular emphasis on the detection of unrealistic low wind speed records with the help of regional references; high variability related erroneous records; wind speed biases on week to monthly timescales and homogenization of wind direction records. As a result, around 1.7% of wind speed records and 0.4% of wind direction records have been deleted, making a combined total of 1.9% of removed records. Around 2.4% of wind direction data have been also corrected. The already quality controlled database allows for subsequent climatological analyses. The intra and inter decadal variability of the monthly surface wind field in such a vast and orographically complex region as the North Eastern North America is explored. Several decades of quality

  3. Mid-latitude tropospheric ozone columns from the MOZAIC program: climatology and interannual variability

    Directory of Open Access Journals (Sweden)

    R. M. Zbinden

    2006-01-01

    Full Text Available Several thousands of ozone vertical profiles collected in the course of the MOZAIC programme (Measurements of Ozone, Water Vapour, Carbon Monoxide and Nitrogen Oxides by In-Service Airbus Aircraft from August 1994 to February 2002 are investigated to bring out climatological and interannual variability aspects. The study is centred on the most frequently visited MOZAIC airports, i.e. Frankfurt (Germany, Paris (France, New York (USA and the cluster of Tokyo, Nagoya and Osaka (Japan. The analysis focuses on the vertical integration of ozone from the ground to the dynamical tropopause and the vertical integration of stratospheric-origin ozone throughout the troposphere. The characteristics of the MOZAIC profiles: frequency of flights, accuracy, precision, and depth of the troposphere observed, are presented. The climatological analysis shows that the Tropospheric Ozone Column (TOC seasonal cycle ranges from a wintertime minimum at all four stations to a spring-summer maximum in Frankfurt, Paris, and New York. Over Japan, the maximum occurs in spring presumably because of the earlier springtime sun. The incursion of monsoon air masses into the boundary layer and into the mid troposphere then steeply diminishes the summertime value. Boundary layer contributions to the TOC are 10% higher in New York than in Frankfurt and Paris during spring and summer, and are 10% higher in Japan than in New York, Frankfurt and Paris during autumn and early spring. Local and remote anthropogenic emissions, and biomass burning over upstream regions of Asia may be responsible for the larger low- and mid-tropospheric contributions to the tropospheric ozone column over Japan throughout the year except during the summer-monsoon season. A simple Lagrangian analysis has shown that a minimum of 10% of the TOC is of stratospheric-origin throughout the year. Investigation of the short-term trends of the TOC over the period 1995–2001 shows a linear increase 0.7%/year in

  4. Climatological characterization of wind and snowfall in Minnesota and assessing the impacts of living snow fences

    Science.gov (United States)

    Shulski, Martha Elizabeth Durr

    Blowing and drifting snow on roadways is a common occurrence in Minnesota due to the topographic, vegetative, and winter climate characteristics of this area. Through proper road design and the use of snow fences this problem can be alleviated, however snowfall and wind climatological information must first be analyzed. Archived climatological records for locations in Minnesota were recently compiled. Snowfall time series data show a statistically significant increase of 28cm in the annual total since 1890. The increase is shown to occur for November--December while February and March show a decrease. This increase is largely due to an increase in the frequency of snow events less than 10cm. Wind data from federal observing sites in Minnesota show a correlation to landscape variability, with a high frequency of higher wind speeds in western and southern Minnesota. A snow relocation factor needed to quantify seasonal snow transport was calculated and shows a strong dependence on the wind speed distribution. A case study of the 2000--01 winter season allowed for examination of snow storage and agricultural implications of three living snow fence designs in southern Minnesota (two 8-row strips of corn, twin-row honeysuckle, single-row honeysuckle/red cedar). For a winter with high seasonal snowfall and spring rainfall, results of snow storage and modeled seasonal snow transport show good agreement for the two corn row strips. However, snow storage totaled approximately 50% of the modeled snow transport for the honeysuckle fence designs, which appeared to reach storage capacity prior to the end of the snow season. A key factor is the absence of a bottom gap, which promotes leeward displacement of the downwind drift and prevents snow deposition on the fence. Soil temperature and frost depth data show a moderation in temperatures and a decrease in freezing depth with an increase in associated snowpack depth. Post-season soil moisture shows no significant variability with

  5. Long-term dust climatology in the western United States reconstructed from routine aerosol ground monitoring

    Directory of Open Access Journals (Sweden)

    D. Q. Tong

    2012-06-01

    Full Text Available This study introduces an observation-based dust identification approach and applies it to reconstruct long-term dust climatology in the western United States. Long-term dust climatology is important for quantifying the effects of atmospheric aerosols on regional and global climate. Although many routine aerosol monitoring networks exist, it is often difficult to obtain dust records from these networks, because these monitors are either deployed far away from dust active regions (most likely collocated with dense population or contaminated by anthropogenic sources and other natural sources, such as wildfires and vegetation detritus. Here we propose an approach to identify local dust events relying solely on aerosol mass and composition from general-purpose aerosol measurements. Through analyzing the chemical and physical characteristics of aerosol observations during satellite-detected dust episodes, we select five indicators to be used to identify local dust records: (1 high PM10 concentrations; (2 low PM2.5/PM10 ratio; (3 higher concentrations and percentage of crustal elements; (4 lower percentage of anthropogenic pollutants; and (5 low enrichment factors of anthropogenic elements. After establishing these identification criteria, we conduct hierarchical cluster analysis for all validated aerosol measurement data over 68 IMPROVE sites in the western United States. A total of 182 local dust events were identified over 30 of the 68 locations from 2000 to 2007. These locations are either close to the four US Deserts, namely the Great Basin Desert, the Mojave Desert, the Sonoran Desert, and the Chihuahuan Desert, or in the high wind power region (Colorado. During the eight-year study period, the total number of dust events displays an interesting four-year activity cycle (one in 2000–2003 and the other in 2004–2007. The years of 2003, 2002 and 2007 are the three most active dust periods, with 46, 31 and 24

  6. Global Lightning Climatology from the Tropical Rainfall Measuring Mission (TRMM), Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD)

    Science.gov (United States)

    Cecil, Daniel J.; Buechler, Dennis E.; Blakeslee, Richard J.

    2015-01-01

    The Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) has been collecting observations of total lightning in the global tropics and subtropics (roughly 38 deg S - 38 deg N) since December 1997. A similar instrument, the Optical Transient Detector, operated from 1995-2000 on another low earth orbit satellite that also saw high latitudes. Lightning data from these instruments have been used to create gridded climatologies and time series of lightning flash rate. These include a 0.5 deg resolution global annual climatology, and lower resolution products describing the annual cycle and the diurnal cycle. These products are updated annually. Results from the update through 2013 will be shown at the conference. The gridded products are publicly available for download. Descriptions of how each product can be used will be discussed, including strengths, weaknesses, and caveats about the smoothing and sampling used in various products.

  7. Status and Plans for the WCRP/GEWEX Global Precipitation Climatology Project (GPCP)

    Science.gov (United States)

    Adler, Robert F.

    2007-01-01

    The Global Precipitation Climatology Project (GPCP) is an international project under the auspices of the World Climate Research Program (WCRP) and GEWEX (Global Water and Energy Experiment). The GPCP group consists of scientists from agencies and universities in various countries that work together to produce a set of global precipitation analyses at time scales of monthly, pentad, and daily. The status of the current products will be briefly summarized, focusing on the monthly analysis. Global and large regional rainfall variations and possible long-term changes are examined using the 27-year (1 979-2005) monthly dataset. In addition to global patterns associated with phenomena such as ENSO, the data set is explored for evidence of long-term change. Although the global change of precipitation in the data set is near zero, the data set does indicate a small upward change in the Tropics (25s-25N) during the period,. especially over ocean. Techniques are derived to isolate and eliminate variations due to ENS0 and major volcanic eruptions and the significance of the linear change is examined. Plans for a GPCP reprocessing for a Version 3 of products, potentially including a fine-time resolution product will be discussed. Current and future links to IPWG will also be addressed.

  8. Climatology of extreme daily precipitation in Colorado and its diverse spatial and seasonal variability

    Science.gov (United States)

    Mahoney, Kelly M.; Ralph, F. Martin; Walter, Klaus; Doesken, Nolan; Dettinger, Michael; Gottas, Daniel; Coleman, Timothy; White, Allen

    2015-01-01

    The climatology of Colorado’s historical extreme precipitation events shows a remarkable degree of seasonal and regional variability. Analysis of the largest historical daily precipitation totals at COOP stations across Colorado by season indicates that the largest recorded daily precipitation totals have ranged from less than 60 mm day−1 in some areas to more than 250 mm day−1 in others. East of the Continental Divide, winter events are rarely among the top 10 events at a given site, but spring events dominate in and near the foothills; summer events are most common across the lower-elevation eastern plains, while fall events are most typical for the lower elevations west of the Divide. The seasonal signal in Colorado’s central mountains is complex; high-elevation intense precipitation events have occurred in all months of the year, including summer, when precipitation is more likely to be liquid (as opposed to snow), which poses more of an instantaneous flood risk. Notably, the historic Colorado Front Range daily rainfall totals that contributed to the damaging floods in September 2013 occurred outside of that region’s typical season for most extreme precipitation (spring–summer). That event and many others highlight the fact that extreme precipitation in Colorado has occurred historically during all seasons and at all elevations, emphasizing a year-round statewide risk.

  9. Climatology, hydrology, and simulation of an emergency outlet, Devils Lake basin, North Dakota

    Science.gov (United States)

    Wiche, Gregg J.; Vecchia, A.V.; Osborne, Leon; Wood, Carrie M.; Fay, James T.

    2000-01-01

    Devils Lake is a natural lake in northeastern North Dakota that is the terminus of a nearly 4,000-square-mile subbasin in the Red River of the North Basin. The lake has not reached its natural spill elevation to the Sheyenne River (a tributary of the Red River of the North) in recorded history. However, geologic evidence indicates a spill occurred sometime within the last 1,800 years. From 1993 to 1999, Devils Lake rose 24.5 feet and, at the present (August 2000), is about 13 feet below the natural spill elevation. The recent lake-level rise has caused flood damages exceeding $300 million and triggered development of future flood-control options to prevent further infrastructure damage and reduce the risk of a potentially catastrophic uncontrolled spill. Construction of an emergency outlet from the west end of Devils Lake to the Sheyenne River is one flood-control option being considered. This report describes the climatologic and hydrologic causes of the recent lake level rise, provides information on the potential for continued lake-level rises during the next 15 years, and describes the potential effectiveness of an emergency outlet in reducing future lake levels and in reducing the risk of an uncontrolled spill. The potential effects of an outlet on downstream water quantity and quality in the upper Sheyenne River also are described.

  10. A Topside Equatorial Ionospheric Density and Composition Climatology During and After Extreme Solar Minimum

    Science.gov (United States)

    Klenzing, J. H.; Simoes, F.; Ivanov, S.; Heelis, R. A.; Bilitza, D.; Pfaff, R. F.; Rowland, D. E.

    2011-01-01

    During the recent solar minimum, solar activity reached the lowest levels observed during the space age. This extremely low solar activity has accompanied a number of unexpected observations in the Earth's ionosphere and thermosphere when compared to previous solar minima. Among these are the fact that the ionosphere is significantly contracted beyond expectations based on empirical models. Climatological altitude profiles of ion density and composition measurements near the magnetic dip equator are constructed from the C/NOFS satellite to characterize the shape of the top side ionosphere during the recent solar minimum and into the new solar cycle. The variation of the profiles with respect to local time, season, and solar activity are compared to the IRI-2007 model. Building on initial results reported by Heelis et al. [2009], here we describe the extent of the contracted ionosphere, which is found to persist throughout 2009. The shape of the ionosphere during 2010 is found to be consistent with observations from previous solar minima.

  11. Climatology Comparison Studies of Precipitations Between GPCP and Rain Gauges in China

    Institute of Scientific and Technical Information of China (English)

    ZI Yong; XU Yinlong; FU Yunfei

    2006-01-01

    The Global Precipitation Climatology Project (GPCP) monthly rainfall data and the rainfall records observed by 740 rain gauges in the mainland of China are used to analyze similarities and differences of the precipitation in China in the period from January 1980 to December 2000. Results expose significantly consistent rainfall distributions between the both data in multi-year mean, multi-year seasonal mean, and multi-year monthly mean. Departures of monthly rainfall for each dataset also show a high correlation with an over 0.8 correlation coefficient. Analysis indicates small differences of both datasets during autumn,winter, and spring, but relative large ones in summer. Generally, the GPCP has trend of overestimating the rainfall rate. Based on above good relationship of both datasets, the GPCP data are used to represent distributions and variations of precipitation in the Tibetan Plateau and Northwest China. Results indicate positive departures of precipitation in summer in the west part of Tibetan Plateau in the 1980s and negative departures after the 1980s. For the west part of Northwest China, analysis illustrates precipitation decreases a little, but no clear variation tendency.

  12. Climatology of Gravity Wave Characteristics and Middle Atmosphere Thermal Structure Characteristics over Reunion Islands, France

    Science.gov (United States)

    Prasanth, Vishnu

    2016-07-01

    In this paper, climatological characteristics of the gravity wave activities and thermal structure activities are studied using temperature profiles obtained from Rayleigh lidar located at Reunion Island (20.8°S, 55.5°E) over a period of ~14 years (1994-2007). The study has been performed over the height range from 30 to 65 km. The overall monthly mean temperature shows a maximum of 265-270K at the stratopause height region from ˜44-52km and peaks during the months of March and November. While there is no clear signature of seasonal oscillation in the stratopause height, the stratopause temperature shows distinct maxima during the periods March-April and October-November. The GW characteristics in terms of time (frequency), height (wave number) and GW associated Potential Energy and their seasonal dependences are presented. Generally, the temporal evolution of temperature profile illustrates the downward phase propagation indicating that the energy is propagating upward. The wave activity is clearly visible with the wave periods ranging from 260 min to 32 min. The dominant components have vertical wavelengths in the range of about ~4 km to 35 km. It is found that the seasonal variation of potential energy is maximum during summer in the upper stratosphere and lower mesosphere. A semiannual variation is seen in the gravity wave activity over all height ranges in the months of February and August.

  13. The archive and library of the former Italian Central Office for Meteorology and Climatology

    Science.gov (United States)

    Beltrano, M. C.; Esposito, S.; Iafrate, L.

    2012-04-01

    The Paper Archive and Library of CRA-CMA (Agricultural Research Council - Research Unit for Climatology and Meteorology applied to Agriculture) are an important source of meteorological data for climate research. CRA-CMA's Paper Archive gathers a collection of about 850 historical meteorological datasets. Among them, 40 are nowadays still in progress, 260 are more than thirty years long and 20 exceed one century. Moreover, the specialized Library of CRA-CMA gathers several publications containing meteorological data from many Italian and foreign observatories and an important collection of scientific journals and historical books on Atmospheric Sciences, Geophysics and Agrometeorology published both in Italy and abroad and dating from the second half of the sixteenth century. Even if input data for climate models are generally based on 30 yr long datasets, nevertheless longer observational series (up to 50 or 100 yr) are a key element to better understand the climate system behavior. Until today, the library described in this paper is a CRA-CMA heritage almost unknown to the international scientific community.

  14. Climatology and trend analysis of extreme precipitation in subregions of Northeast Brazil

    Science.gov (United States)

    Oliveira, P. T.; Santos e Silva, C. M.; Lima, K. C.

    2016-07-01

    The present paper aims of computing climatology and trend analysis of occurrence and intensity of extreme events of precipitation in subregions of Northeast Brazil (NEB). We used daily rainfall data of 148 rain gauges collected from the hydrometeorological network managed by the National Water Agency during 1972 to 2002 and used quantiles technique in order to select rainfall events. Defining heavy rainfall events as those when at least one rain gauge recorded rainfall above the 95th percentile, normal rainfall was between the 45th and 55th percentiles, and weak rainfall events were under the 5th percentile. The Mann-Kendall nonparametric test was used to calculate the linear trend of the quantity and intensity of rainfall events. The NEB was divided in five subregions using the cluster analysis based on Euclidean distance and Ward's method: Northern coast, Northern semiarid, Northwest, Southern semiarid, and Southern coast. The results suggest that the subregions are less influenced by El Niño and La Niña, and dry areas have higher variability, with the greatest number of intense events.

  15. The Impact of Climatological Variables on Kelp Canopy Area in the Santa Barbara Channel

    Science.gov (United States)

    Zigner, K.; Bausell, J.; Kudela, R. M.

    2015-12-01

    Kelp canopy area (KCA), a proxy for kelp forest health, has important implications for small and large-scale processes pertaining to fisheries, near shore currents, and marine ecosystems. As part of the NASA Airborne Science Research Program (SARP), this study examines the impact of ocean chemistry and climatological variables on KCA in the Santa Barbara Channel through time series analysis. El Niño Southern Oscillation (ENSO), North Pacific Gyre Oscillation (NPGO), North Pacific Oscillation (NPO), and upwelling indices as well as sea surface temperature (SST), salinity, nitrate, and chlorophyll-a concentrations taken within the Santa Barbara channel (1990-2014) were acquired from the Climate Prediction Center (CPC), California Cooperative Oceanic Fisheries Investigation (CalCOFI), and Di Lorenzo's NPGO websites. These data were then averaged for winter (November-January) and summer (May-August) seasons and compared to KCA measurements derived from Landsat images via unsupervised classification. Regression, cumulative sum tests, and cross-correlation coefficients revealed a two year lag between KCA and the NPGO, indicating the presence of an additional factor driving both variables. Further analyses suggests that the NPO may be this driving factor, as indicated by the correlation (lag 0) with KCA. Comparing relationships between kelp and other variables over various time periods supports the acceleration of the NPGO and other variables in more recent years. Exploring relationships between KCA, NPGO, and NPO may provide insight into potential impacts of climate change on coastal marine ecosystems.

  16. Moisture and heat budgets of the south American monsoon system: climatological aspects

    Science.gov (United States)

    Garcia, Sâmia R.; Kayano, Mary T.; Calheiros, Alan J. P.; Andreoli, Rita Valéria; de Souza, Rodrigo Augusto Ferreira

    2016-08-01

    The climatology of the moisture and heat budget equation terms for subareas within the South American Monsoon System (SAMS) region is investigated for the 1958-2014 period considering the distinct phases of the Pacific Decadal Oscillation (PDO). These budget equations are applied to the data from the National Centers for Environmental Prediction (NCEP) Reanalysis project. Sources or sinks of moisture and heat are equation residues, referred to as residue and diabatic terms, respectively. Analyses are done for the Central Amazon Basin (CAM) and Western-Central Brazil (WCB) for three distinct periods, 1958-1976, 1977-1995, and 1996-2014, that correspond to the cold, warm, and undefined PDO phases. The differences among the PDO phases for each term are discussed. The CAM region acts dominantly as a moisture sink and heat source in all months during the three phases. On the other hand, in the WCB region, the monsoon characteristics are better defined, with a moisture sink (source) and a heat source (sink) during the wet (dry) season. The main result of the present analysis is the persistence of SAMS intensification signs in both CAM and WCB areas up to the last analyzed period (1996-2014), which is consistent with intense flooding in the Amazon Basin in 2008/2009, 2012, and 2014.

  17. Towards climatological study on the characteristics of aerosols in Central Africa and Mediterranean sites

    Science.gov (United States)

    Benkhalifa, Jamel; Chaabane, Mabrouk

    2016-02-01

    The atmosphere contains molecules, clouds and aerosols that are sub-millimeter particles having a large variability in size, shape, chemical composition, lifetime and contents. The aerosols concentration depends greatly on the geographical situation, meteorological and environmental conditions, which makes aerosol climatology difficult to assess. Setting up a solar photometer (automatic, autonomous and portable instrument) on a given site allows carrying out the necessary measurements for aerosol characterization. The particle microphysical and optical properties are obtained from photometric measurements. The objective of this study is to analyze the spatial variability of aerosol optical thickness (AOT) in several Mediterranean regions and Central Africa, we considered a set of simultaneous data in the AErosol RObotic NETwork (AERONET) from six sites, two of which are located in Central Africa (Banizoumbou and Zinder Airport) and the rest are Mediterranean sites (Barcelona, Malaga, Lampedusa, and Forth Crete). The results have shown that the physical properties of aerosols are closely linked to the climate nature of the studied site. The optical thickness, single scattering albedo and aerosols size distribution can be due to the aging of the dust aerosol as they are transported over the Mediterranean basin.

  18. Alpine cloud climatology using long-term NOAA-AVHRR satellite data

    Energy Technology Data Exchange (ETDEWEB)

    Kaestner, M.; Kriebel, K.T.

    2000-07-01

    Three different climates have been identified by our evaluation of AVHRR (advanced very high resolution radiometer) data using APOLLO (AVHRR processing scheme over land, clouds and ocean) for a five-years cloud climatology of the Alpine region. The cloud cover data from four layers were spatially averaged in boxes of 15 km by 14 km. The study area only comprises 540 km by 560 km, but contains regions with moderate, Alpine and Mediterranean climate. Data from the period July 1989 until December 1996 have been considered. The temporal resolution is one scene per day, the early afternoon pass, yielding monthly means of satellite derived cloud coverages 5% to 10% above the daily mean compared to conventional surface observation. At nonvegetated sites the cloudiness is sometimes significantly overestimated. Averaging high resolution cloud data seems to be superior to low resolution measurements of cloud properties and averaging is favourable in topographical homogeneous regions only. The annual course of cloud cover reveals typical regional features as foehn or temporal singularities as the so-called Christmas thaw. The cloud cover maps in spatially high resolution show local luff/lee features which outline the orography. Less cloud cover is found over the Alps than over the forelands in winter, an accumulation of thick cirrus is found over the High Alps and an accumulation of thin cirrus north of the Alps. (orig.)

  19. The global historical climatology network: Long-term monthly temperature, precipitation, and pressure data

    International Nuclear Information System (INIS)

    Interest in global climate change has risen dramatically during the past several decades. In a similar fashion, the number of data sets available to study global change has also increased. Unfortunately, many different organizations and researchers have compiled these data sets, making it confusing and time consuming for individuals to acquire the most comprehensive data. In response to this rapid growth in the number of global data sets, DOE's Carbon Dioxide Information Analysis Center (CDIAC) and NOAA's National Climatic Data Center (NCDC) established the Global Historical Climatology Network (GHCN) project. The purpose of this project is to compile an improved data set of long-term monthly mean temperature, precipitation, sea level pressure, and station pressure for as dense a network of global stations as possible. Specifically, the GHCN project seeks to consolidate the numerous preexisting national-, regional-, and global-scale data sets into a single global data base; to subject the data to rigorous quality control; and to update, enhance, and distribute the data set at regular intervals. The purpose of this paper is to describe the compilation and contents of the GHCN data base (i.e., GHCN Version 1.0)

  20. United States Historical Climatology Network (US HCN) monthly temperature and precipitation data

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, R.C. [ed.] [Univ. of Tennessee, Knoxville, TN (United States). Energy, Environment and Resources Center; Boden, T.A. [ed.] [Oak Ridge National Lab., TN (United States); Easterling, D.R.; Karl, T.R.; Mason, E.H.; Hughes, P.Y.; Bowman, D.P. [National Climatic Data Center, Asheville, NC (United States)

    1996-01-11

    This document describes a database containing monthly temperature and precipitation data for 1221 stations in the contiguous United States. This network of stations, known as the United States Historical Climatology Network (US HCN), and the resulting database were compiled by the National Climatic Data Center, Asheville, North Carolina. These data represent the best available data from the United States for analyzing long-term climate trends on a regional scale. The data for most stations extend through December 31, 1994, and a majority of the station records are serially complete for at least 80 years. Unlike many data sets that have been used in past climate studies, these data have been adjusted to remove biases introduced by station moves, instrument changes, time-of-observation differences, and urbanization effects. These monthly data are available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center. The NDP includes this document and 27 machine-readable data files consisting of supporting data files, a descriptive file, and computer access codes. This document describes how the stations in the US HCN were selected and how the data were processed, defines limitations and restrictions of the data, describes the format and contents of the magnetic media, and provides reprints of literature that discuss the editing and adjustment techniques used in the US HCN.

  1. Climatological characteristics of raindrop size distributions in Busan, Republic of Korea

    Science.gov (United States)

    Suh, S.-H.; You, C.-H.; Lee, D.-I.

    2016-01-01

    Raindrop size distribution (DSD) characteristics within the complex area of Busan, Republic of Korea (35.12° N, 129.10° E), were studied using a Precipitation Occurrence Sensor System (POSS) disdrometer over a 4-year period from 24 February 2001 to 24 December 2004. Also, to find the dominant characteristics of polarized radar parameters, which are differential radar reflectivity (Zdr), specific differential phase (Kdp) and specific attenuation (Ah), T-matrix scattering simulation was applied in the present study. To analyze the climatological DSD characteristics in more detail, the entire period of recorded rainfall was divided into 10 categories not only covering different temporal and spatial scales, but also different rainfall types. When only convective rainfall was considered, mean values of mass-weighted mean diameter (Dm) and normalized number concentration (Nw) values for all these categories converged around a maritime cluster, except for rainfall associated with typhoons. The convective rainfall of a typhoon showed much smaller Dm and larger Nw compared with the other rainfall categories. In terms of diurnal DSD variability, we analyzed maritime (continental) precipitation during the daytime (DT) (nighttime, NT), which likely results from sea (land) wind identified through wind direction analysis. These features also appeared in the seasonal diurnal distribution. The DT and NT probability density function (PDF) during the summer was similar to the PDF of the entire study period. However, the DT and NT PDF during the winter season displayed an inverse distribution due to seasonal differences in wind direction.

  2. Climatological characteristics of the tropics in China: climate classification schemes between German scientists and Huang Bingwei

    Institute of Scientific and Technical Information of China (English)

    ManfredDomroes

    2003-01-01

    Reviewing some important German scientists who have developed climatic regionalization schemes either on a global or Chinese scale, their various definitions of the tropical climate characteristics in China are discussed and compared with Huang Bingwei's climate classification scheme and the identification of the tropical climate therein. It can be seen that, due to different methodological approaches of the climatic regionalization schemes, the definitions of the tropics vary and hence also their spatial distribution in China. However, it is found that the tropical climate type occupies only a peripheral part of southern China, though it firmly represents a distinctive type of climate that is subsequently associated with a great economic importance for China. As such, the tropical climate type was mostly identified with its agro-climatological significance, that is by giving favourable growing conditions all-year round for perennial crops with a great heat demand. Tropical climate is, hence, conventionally regarded to be governed by all-year round summer conditions "where winter never comes".

  3. Venus-Earth-Mars: Comparative Climatology and the Search for Life in the Solar System

    Directory of Open Access Journals (Sweden)

    Roger D. Launius

    2012-09-01

    Full Text Available Both Venus and Mars have captured the human imagination during the twentieth century as possible abodes of life. Venus had long enchanted humans—all the more so after astronomers realized it was shrouded in a mysterious cloak of clouds permanently hiding the surface from view. It was also the closest planet to Earth, with nearly the same size and surface gravity. These attributes brought myriad speculations about the nature of Venus, its climate, and the possibility of life existing there in some form. Mars also harbored interest as a place where life had or might still exist. Seasonal changes on Mars were interpreted as due to the possible spread and retreat of ice caps and lichen-like vegetation. A core element of this belief rested with the climatology of these two planets, as observed by astronomers, but these ideas were significantly altered, if not dashed during the space age. Missions to Venus and Mars revealed strikingly different worlds. The high temperatures and pressures found on Venus supported a “runaway greenhouse theory,” and Mars harbored an apparently lifeless landscape similar to the surface of the Moon. While hopes for Venus as an abode of life ended, the search for evidence of past life on Mars, possibly microbial, remains a central theme in space exploration. This survey explores the evolution of thinking about the climates of Venus and Mars as life-support systems, in comparison to Earth.

  4. Estimated errors in a global gravity wave climatology from GPS radio occultation temperature profiles

    Science.gov (United States)

    de la Torre, A.; Llamedo, P.; Alexander, P.; Schmidt, T.; Wickert, J.

    2010-07-01

    In a previous paper by Schmidt et al. (2008), from CHAllenging Minisatellite Payload (CHAMP) Global Positioning System (GPS) radio occultation data, a comparison was made between a Gaussian filter applied to the "complete" temperature profile and to its "separate" tropospheric and stratospheric height intervals, for gravity wave analyses. It was found that the separate filtering method considerably reduces a wave activity artificial enhancement near the tropopause, presumably due to the isolation process of the wave component. We now propose a simple approach to estimate the uncertainty in the calculation of the mean specific wave potential energy content, due exclusively to the filtering process of vertical temperature profiles, independently of the experimental origin of the data. The approach is developed through a statistical simulation, built up from the superposition of synthetic wave perturbations. These are adjusted by a recent gravity wave (GW) climatology and temperature profiles from reanalyses. A systematic overestimation of the mean specific wave potential energy content is detected and its variability with latitude, altitude, season and averaging height interval is highlighted.

  5. Metrological challenges for measurements of key climatological observables. Part 3: seawater pH

    Science.gov (United States)

    Dickson, A. G.; Camões, M. F.; Spitzer, P.; Fisicaro, P.; Stoica, D.; Pawlowicz, R.; Feistel, R.

    2016-02-01

    Water dissolves many substances with which it comes into contact, leading to a variety of aqueous solutions ranging from simple and dilute to complex and highly concentrated. Of the multiple chemical species present in these solutions, the hydrogen ion, H+, stands out in importance due to its relevance to a variety of chemical reactions and equilibria that take place in aquatic systems. This importance, and the fact that its presence can be assessed by reliable and inexpensive procedures, are the reasons why pH is perhaps the most measured chemical parameter. In this paper, while examining climatologically relevant ocean pH, we note fundamental problems in the definition of this key observable, and its lack of secure foundation on the International System of Units, the SI. The metrological history of seawater pH is reviewed, difficulties arising from its current definition and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent TEOS-10 seawater standard. It is concluded that the International Bureau of Weights and Measures (BIPM), in cooperation with the International Association for the Properties of Water and Steam (IAPWS), along with other international organisations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems.

  6. A 40-year retrospective European radon flux inventory including climatological variability

    Science.gov (United States)

    López-Coto, I.; Mas, J. L.; Bolivar, J. P.

    2013-07-01

    In this work, a 40-year retrospective European radon flux inventory has been calculated. Average values of the radon exhalation rate, probability distributions and seasonal fluctuations have been obtained. To achieve this, a numerical model of radon transport through finite, heterogeneous and porous media has been implemented, enabling us to calculate the radon exhalation rate of European soils with a horizontal resolution of 0.5' (˜1 km). Geological, geochemical and climatological parameters derived from European and international databases (FOREGS, HWSD, ERA-40) have been coupled to the model. The theoretical model is based on the fundamental equation of radon transport in porous media, taking into account the dependency of the transport coefficient on temperature and humidity. It also includes a simple model that evaluates the effect of snow cover. In general, the results show wide variations depending on location and season of the year, with a spatial standard deviation close to the annual average value (30 Bq m-2 h-1) In turn, the seasonal deviation is about 25% of the annual average value. The inventory can be easily integrated into atmospheric transport models acting as baseline that could be used for policy decisions regarding the identification of areas with a high risk of exposure to radon. The gridded data are available for the scientific community upon request. The limitations and sources of errors and uncertainties of the model are also discussed in detail.

  7. Contribution of the Ebro Observatory team to the IRI climatological modeling: A Review.

    Science.gov (United States)

    Altadill, David; Blanch, Estefania; Miquel Torta, J.

    During the recent years, the Geomagnetism and Aeronomy group of the Ebre Observatory has been working to improve the climatological prediction of some ionospheric key parameters. To do that, we have taken advantage of the increasing number of ionospheric stations providing data and sharing it through the Digital Ionospheric Data Base (DIDB). We have used the Spherical Harmonic analysis as analytical technique for globally modeling those parameters during quiet conditions. Models for bottom-side B0 and B1 parameters of IRI, for density peak height (hmF2) and for equivalent scale height (Hm) have been developed. Each SH model has been parameterized according to the time-space pattern of respectively ionospheric parameter and has been bounded to the solar activity. It has been proved that these empirical models improve, in average, the prediction of B0, B1 and hmF2 by 40%, 20% and 10% respectively with respect to previous IRI versions (hmF2 is improved by more than 30% at high and low latitudes). Due to these good results and to the analytical formulation, IRI has adopted the SH empirical models for B0 and B1 as an option in the current version (IRI 2012) and has proposed the SH model for hmF2 to be included into next releases. The analytical model for Hm could be useful to estimate information for the topside profile formulation.

  8. Climatology of the Ionospheric Scintillations over the Auroral and Cusp European Regions

    Science.gov (United States)

    Spogli, L.; Alfonsi, L.; de Franceschi, G.; Romano, V.; Aquino, M.; Dodson, A.

    2009-04-01

    Under perturbed conditions coming from the outer space, the ionosphere may become highly turbulent and small scale (from centimeters to meters) irregularities, typically enhancements or depletions of the electron density embedded in the ambient ionosphere, can form causing diffraction effects on the satellites signals passing through them. Such effect can abruptly corrupt the performance of the positioning systems affecting, in turn, the awareness and safety of the modern devices. In this paper we analyze data of ionospheric scintillation in the latitudinal range 57°- 88° N during the period October, November and December 2003 as a first step to develop a "scintillation climatology" over the Northern Europe. The behavior of the scintillation occurrence as function of the magnetic local time and of the corrected magnetic latitude is investigated to characterize the scintillation conditions. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) and the Institute of Engineering Surveying and Space Geodesy (IESSG) of the University of Nottingham manage the same kind of GISTM (GPS Ionospheric Scintillation and TEC monitor) receivers over the European middle and high latitude regions. The results here shown and obtained merging observations from three GISTM, highlight also the possibility to investigate the dynamics of irregularities causing scintillation by combining the information coming from auroral to cusp latitudes. The findings, even if at a very preliminary stage, are here presented also in the frame of possible Space Weather implications.

  9. Metrological challenges for measurements of key climatological observables. Part 4: atmospheric relative humidity

    Science.gov (United States)

    Lovell-Smith, J. W.; Feistel, R.; Harvey, A. H.; Hellmuth, O.; Bell, S. A.; Heinonen, M.; Cooper, J. R.

    2016-02-01

    Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest ‘greenhouse’ gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. In this paper, we examine the climatologically relevant atmospheric relative humidity, noting fundamental deficiencies in the definition of this key observable. The metrological history of this quantity is reviewed, problems with its current definition and measurement practice are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures (BIPM), in cooperation with the International Association for the Properties of Water and Steam (IAPWS), along with other international organizations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions, such as are suggested here, for what are long-standing metrological problems.

  10. Cloud climatology in the Canary Islands region using NOAA-AVHRR data

    Science.gov (United States)

    González, Albano; Cerdeña, Abidán; Pérez, Juan C.; Díaz, Ana M.

    2007-10-01

    In this work a threshold technique for cloud detection and classification is applied to 9 years NOAA-AVHRR imagery in order to obtain a cloud climatology of the Canary Islands region (Northeast Atlantic Ocean). Once the clouds are classified, a retrieval method is used to estimate cloud macro- and micro-physical parameters, such as, effective particle size, optical thickness and top temperature. This retrieval method is based on the inversion of the simulated radiances obtained by a numerical radiative transfer model, libRadtran, using artificial neural networks (ANNs). The ANNs, whose architecture was based on Multilayer Perceptron model, were trained with simulated theoretical radiances using backpropagation with momentum method, and their architectures were optimized through genetic algorithms. The global procedure was performed for both day and night overpasses and, from a set of more than 9000 images, maps of relative frequency were calculated. These results were compared with ISCCP data for the 21-year period 1984-2004. The relationships between the retrieved cloud properties and some climate and atmospheric variables were also considered.

  11. Synthesis of results obtained within the framework of international satellite land surface climatology projects. Final report

    International Nuclear Information System (INIS)

    In large-scale field experiments, methods were validated with whose aid characteristics of the terrestrial surfaces can be derived from satellite data; these characteristics are required for the exploration of the global change. The report gives an overview. The following topics are treated: Problems of calibration of satellite sensors; the geographical matching of ground observations to the satellite measurements; necessary corrections; dimensional integration of the data up to the dimensions of raster grids of global climate models. The report discusses in detail in what manner the remote exploration data can be connected with information on the terrestrial surfaces, in particular with energy balances. Few experiments only have been executed up to now within the framework of land surface climatology; however, they contributed a great deal to the better understanding of linking satellite data with terrestrial surface processes. If one wants to apply the elaborated methods globally wants, one needs, however, complex algorithms as well as - at least for the time being - constant quality control in the different landscape regions of the earth. (orig.)

  12. A global ETCCDI based precipitation climatology from satellite and rain gauge measurements

    Science.gov (United States)

    Dietzsch, Felix; Andersson, Axel; Schröder, Marc; Ziese, Markus; Becker, Andreas

    2016-04-01

    The project framework MiKlip ("Mittelfristige Klimaprognosen") is focused onto the development of an operational forecast system for decadal climate predictions. The objective of the "Daily Precipitation Analysis for the validation of Global medium-range Climate predictions Operationalized" (DAPAGLOCO) project, is the development and operationalization of a global precipitation dataset for forecast validation of the MPI-ESM experiments used in MiKlip. The dataset is a combination of rain gauge measurement data over land and satellite-based precipitation retrievals over ocean. Over land, gauge data from the Global Precipitation Climatology Centre (GPCC) at Deutscher Wetterdienst (DWD) are used. Over ocean, retrievals from the Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data (HOAPS) dataset are used as data source. The currently available dataset consists of 21 years of data (1988-2008) and has a spatial resolution of 1°. So far, the MiKlip forecast validation is based upon the Expert Team on Climate Change and Detection Indices (ETCCDI). These indices focus on precipitation extrema in terms of spell durations, percentiles, averaged precipitation amounts and further more. The application of these indices on the DAPAGLOCO dataset in its current state delivers insight into the global distribution of precipitation characteristics and extreme events. The resulting global patterns of these characteristics and extrema are the main objective of the presentation.

  13. Hydro-climatological Impact of Century Long Drainage in Midwestern United States

    Science.gov (United States)

    Kumar, S.; Merwade, V.; Bain, D. J.

    2008-12-01

    Today's Corn Belt in the Midwest USA is located on an area which was largely wetlands 150 years ago. Compared to the pre-European settlement baseline, more than 85% of wetland area has been lost. Large scale artificial drainage activity, which peaked between 1900 and 1930, is primarily responsible for this decrease in wetland area. The consequences of wetland drainage have been characterized including diminished flood storage, changes in vegetation community composition, habitat loss, and changes in bio- geochemistry (e.g., carbon sink to carbon source). However, one potentially important impact, the effect of wetland loss on regional hydro-climatology (temperature and precipitation), has not been characterized. This study will: (a) present the history of artificial drainage in Midwest USA from 1860 to present, and (b) discuss the interaction between wetland drainage and the atmosphere using modeling experiments. Study area encompassing 8 states in Midwest USA (293 million acre) contains intensively drained states like Indiana and Ohio, as well as less drained states like Wisconsin and Missouri. Geospatial data sets of drainage acreages at county scale are based on US census reports from 1920 to 1980 and contemporary wetland data are based on remote sensing data. Interaction between wetland drainage and the atmosphere will be modeled using a coupled land surface and regional climate model.

  14. Land surface skin temperature climatology: benefitting from the strengths of satellite observations

    Energy Technology Data Exchange (ETDEWEB)

    Jin Menglin [Department of Meteorology, San Jose State University, 1 Washington Square, San Jose, CA 95192-0104 (United States); Dickinson, Robert E, E-mail: jin@met.sjsu.edu [Jackson School of Geosciences, University of Texas at Austin (United States)

    2010-10-15

    Surface skin temperature observations (T{sub skin}), as obtained by satellite remote sensing, provide useful climatological information of high spatial resolution and global coverage that enhances the traditional ground observations of surface air temperature (T{sub air}) and so, reveal new information about land surface characteristics. This letter analyzes nine years of moderate-resolution imaging spectroradiometer (MODIS) skin temperature observations to present monthly skin temperature diurnal, seasonal, and inter-annual variations at a 0.05 deg. latitude/longitude grid over the global land surface and combines these measurements with other MODIS-based variables in an effort to understand the physical mechanisms responsible for T{sub skin} variations. In particular, skin temperature variations are found to be closely related to vegetation cover, clouds, and water vapor, but to differ from 2 m surface T{sub air} in terms of both physical meaning and magnitude. Therefore, the two temperatures (T{sub skin} and T{sub air}) are complementary in their contribution of valuable information to the study of climate change.

  15. Basin-scale wind transport during the MILAGRO field campaign and comparison to climatology using cluster analysis

    OpenAIRE

    De Foy, B.; J. D. Fast; S. J. Paech; Phillips, D; Walters, J. T.; Coulter, R. L.; Martin, T. J.; M. S. Pekour; Shaw, W.J.; Kastendeuch, P. P.; Marley, N. A.; Retama, A.; L. T. Molina

    2007-01-01

    The MILAGRO field campaign was a multi-agency international collaborative project to evaluate the regional impacts of the Mexico City air pollution plume as a means of understanding urban impacts on the global climate. Mexico City lies on an elevated plateau with mountains on three sides and has complex mountain and surface-driven wind flows. This paper asks what the wind transport was in the basin during the field campaign and how representative it was of the climatology. Surface meteorology...

  16. Structure and Propagation Characteristics of Climatological Mean Kinetic Energy of Disturbance of Intraseasonal Oscillation in Asian Summer Monsoon Zone

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The research aimed to study the structure and propagation characteristics of climatological mean kinetic energy of disturbance of intraseasonal oscillation in Asian summer monsoon zone. [Method] When South China Sea monsoon started to break out, the kinetic energy of intraseasonal oscillation disturbance in the monsoon zone was analyzed, especially the researches about the variation of South China Sea monsoon, the development of Indian monsoon and the advancement of East Asian monsoon. [Result] ...

  17. Climatology Analysis of Aerosol Effect on Marine Water Cloud from Long-Term Satellite Climate Data Records

    OpenAIRE

    Xuepeng Zhao; Andrew K. Heidinger; Andi Walther

    2016-01-01

    Satellite aerosol and cloud climate data records (CDRs) have been used successfully to study the aerosol indirect effect (AIE). Data from the Advanced Very High Resolution Radiometer (AVHRR) now span more than 30 years and allow these studies to be conducted from a climatology perspective. In this paper, AVHRR data are used to study the AIE on water clouds over the global oceans. Correlation analysis between aerosol optical thickness (AOT) and cloud parameters, including cloud droplet effecti...

  18. Climatology of new particle formation at Izaña mountain GAW observatory in the subtropical North Atlantic

    OpenAIRE

    M. I. García; S. Rodríguez; González, Y.; García, R. D.

    2014-01-01

    A climatology of new particle formation (NPF) events at high altitude in the subtropical North Atlantic is presented. A 4-year data set (June 2008–June 2012), which includes number size distributions (10–600 nm), reactive gases (SO2, NOx, and O3), several components of solar radiation and meteorological parameters, measured at Izaña Global Atmosphere Watch (GAW) observatory (2373 m above sea level; Tenerife, Canary Islands) was analysed. NPF is associated with the transpo...

  19. Climatology and variability of trace gases in extratropical double-tropopause regions from MLS, HIRDLS, and ACE-FTS measurements

    OpenAIRE

    M. J. Schwartz; Manney, G. L.; Hegglin, M. I.; N. J. Livesey; M. L. Santee; W. H. Daffer

    2015-01-01

    Upper tropospheric and lower stratospheric measurements from the Aura Microwave Limb Sounder (MLS), the Aura High Resolution Dynamics Limb Sounder (HIRDLS), and the Atmospheric Chemistry Experiment-Fourier transform spectrometer (ACE-FTS) are used to present the first global climatological comparison of extratropical, nonpolar trace gas distributions in double-tropopause (DT) and single-tropopause (ST) regions. Stratospheric tracers, O3, HNO3, and HCl, have lower mixing ratios ∼2–8 km above t...

  20. Modelling sea breeze climatologies and interactions on coasts in the southern North Sea: Implications for offshore wind energy

    OpenAIRE

    Steele, Christopher; Dorling, Stephen; von Glasow, Roland; Bacon, Jim

    2015-01-01

    Current understanding of the behaviour of sea breezes in the offshore environment is limited but rapidly requires improvement due, not least, to the expansion of the offshore wind energy industry. Here we report on contrasting characteristics of three sea-breeze types on five coastlines around the southern North Sea from an 11 year model-simulated climatology. We present and test an identification method which distinguishes sea-breeze types which can, in principle, be adapted for other coastl...

  1. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter

    OpenAIRE

    Krüger, Kirstin; Tegtmeier, Susann; Rex, Markus

    2008-01-01

    A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TTL, the averaged diabatic as...

  2. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter

    OpenAIRE

    Krüger, K.; Tegtmeier, S.; Rex, M.

    2008-01-01

    A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962?2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TTL, the averaged diabatic as...

  3. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter

    OpenAIRE

    Krüger, K.; Tegtmeier, S.; Rex, M.

    2007-01-01

    A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the TTL, the averaged diabatic ascent is ...

  4. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter

    OpenAIRE

    Krüger, K.; Tegtmeier, S.; Rex, M.

    2007-01-01

    A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962?2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the TTL, the averaged diabatic ascent is 0.5 K/day ...

  5. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter

    OpenAIRE

    Krüger, K.; Tegtmeier, S.; Rex, M.

    2008-01-01

    A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TTL, the averaged d...

  6. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter

    OpenAIRE

    Krüger, K.; Tegtmeier, S.; Rex, M.

    2007-01-01

    A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962?2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TTL, the averaged diabatic as...

  7. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL) during NH winter

    OpenAIRE

    Krüger, K.; Tegtmeier, S.; Rex, M.

    2008-01-01

    A long-term climatology of air mass transport through the tropical tropopause layer (TTL) is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TT...

  8. Deriving a sea surface climatology of CO2 fugacity in support of air–sea gas flux studies

    Directory of Open Access Journals (Sweden)

    L. M. Goddijn-Murphy

    2014-07-01

    Full Text Available Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean Carbon Dioxide (CO2 Atlas (SOCAT has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, fCO2. fCO2 is highly sensitive to temperature and the measurements are only valid for the instantaneous sea surface temperature (SST that is measured concurrent with the in-water CO2 measurement. To create a climatology of fCO2 data suitable for calculating air–sea CO2 fluxes it is therefore desirable to calculate fCO2 valid for climate quality SST. This paper presents a method for creating such a climatology. We recomputed SOCAT's fCO2 values for their respective measurement month and year using climate quality SST data from satellite Earth observation and then extrapolated the resulting fCO2 values to reference year 2010. The data were then spatially interpolated onto a 1° × 1° grid of the global oceans to produce 12 monthly fCO2 distributions for 2010. The partial pressure of CO2 (pCO2 is also provided for those who prefer to use pCO2. The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air–sea CO2 flux, and hence the presented fCO2 distributions can be used in air–sea gas flux calculations together with climatologies of other climate variables.

  9. South American Climatology and Impacts of El Niño in NCEP’s CFSR Data

    OpenAIRE

    Timothy Paul Eichler; Ana C. Londoño

    2013-01-01

    Understanding regional climate variability is necessary in order to assess the impacts of climate change. Until recently, the best methods for evaluating regional climate variability were via observation networks and coarse-gridded reanalysis datasets. However, the recent development of high-resolution reanalysis datasets offers an opportunity to better evaluate the climatologically diverse continent of South America. This study compares NCEP’s CFS reanalysis dataset with NCEP’s coarser-resol...

  10. Argument about the climatological-meteorological data base of the German Risk Study on Nuclear Power Plants

    International Nuclear Information System (INIS)

    The Ecological Institute's doubts about the representativeness of the climatological-meteorological data base of the German Risk Study concludes that this data base with its 115 'weather sequences' combined with 36 'wind directions' has no defined reference period. The complementary frequency distributions of the German Risk Study do not, therefore, represent statistically secured occurence frequencies for damage caused by accidents. Furthermore, incorrect values for the height of mixing layers used in the German Risk Study were found. (RF)

  11. Historical oceanographic data and climatologies in support of the Deepwater Horizon oil spill event in the Gulf of Mexico (NODC Accession 0064867)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data products and in situ oceanographic data collected as part of the Deepwater Horizon Event in the Gulf of Mexico (May 2010). The climatological fields detailed...

  12. 4 km NODC/RSMAS AVHRR Pathfinder Version 5.0 and 5.1 Daily Harmonic Climatologies (1982-2008) (NODC Accession 0071181)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains a global, 4km daily sea surface temperature climatology derived from harmonic analysis of the AVHRR Pathfinder Version 5.0 and 5.1 sea...

  13. An Aircraft-Based Upper Troposphere Lower Stratosphere O3, CO, and H2O Climatology for the Northern Hemisphere

    Science.gov (United States)

    Tilmes, S.; Pan, L. L.; Hoor, P.; Atlas, E.; Avery, M. A.; Campos, T.; Christensen, L. E.; Diskin, G. S.; Gao, R.-S.; Herman, R. L.; Hinsta, E. J.; Loewenstein, M.; Lopez, J.; Paige, M. E.; Pittman, J. V.; Podolske, J. R.; Proffitt, M. R.; Sachse, G. W.; Schiller, C.; Schlager, H.; Smith, J.; Spelten, N.; Webster, C.; Weinheimer, A.; Zondlo, M. A.

    2010-01-01

    We present a climatology of O3, CO, and H2O for the upper troposphere and lower stratosphere (UTLS), based on a large collection of high ]resolution research aircraft data taken between 1995 and 2008. To group aircraft observations with sparse horizontal coverage, the UTLS is divided into three regimes: the tropics, subtropics, and the polar region. These regimes are defined using a set of simple criteria based on tropopause height and multiple tropopause conditions. Tropopause ]referenced tracer profiles and tracer ]tracer correlations show distinct characteristics for each regime, which reflect the underlying transport processes. The UTLS climatology derived here shows many features of earlier climatologies. In addition, mixed air masses in the subtropics, identified by O3 ]CO correlations, show two characteristic modes in the tracer ]tracer space that are a result of mixed air masses in layers above and below the tropopause (TP). A thin layer of mixed air (1.2 km around the tropopause) is identified for all regions and seasons, where tracer gradients across the TP are largest. The most pronounced influence of mixing between the tropical transition layer and the subtropics was found in spring and summer in the region above 380 K potential temperature. The vertical extent of mixed air masses between UT and LS reaches up to 5 km above the TP. The tracer correlations and distributions in the UTLS derived here can serve as a reference for model and satellite data evaluation

  14. Use of RegCM gridded dataset for thunderstorm favorable conditions analysis over Poland—climatological approach

    Science.gov (United States)

    Walawender, Ewelina; Kielar, Rafał; Ustrnul, Zbigniew

    2015-09-01

    The paper analyzes equivalent data for a low density meteorological station network (spatially discontinuous data) and poor temporal homogeneity of thunderstorm observational data. Due to that, a Regional Climate Model (RegCM) dataset was tested. The Most Unstable Convective Available Potential Energy index value (MUCAPE) above the 200 J kg-1 threshold was selected as a predictor describing favorable conditions for the occurrence of thunderstorms. The quality of the dataset was examined through a comparison between model results and soundings from several aerological stations in Central Europe. Good, statistically significant (0.05 significance level) results were obtained through correlation analysis; the value of Pearson's correlation coefficient was above 0.8 in every single case. Then, using methods associated with gridded climatology, data series for 44 weather stations were derived and an analysis of correlation between RegCM modeled data and in situ thunderstorm observations was conducted with coefficients in the range of 0.75-0.90. The possibility of employing the dataset in thunderstorm climatology analysis was checked via a few examples by mapping monthly, seasonal, and annual means. Moreover, long-term variability and trend analysis along with modeled MUCAPE data were tested. As a result, the RegCM modeled MUCAPE gridded dataset was proposed as an easily available, suitable, and valuable predictor for thunderstorm climatology analysis and mapping. Finally, some limitations are discussed and recommendations for further improvements are given.

  15. A regional rainfall climatology over Mexico and the southwest United States derived from passive microwave and geosynchronous infrared data

    Energy Technology Data Exchange (ETDEWEB)

    Negri, A.J.; Adler, R.F. (NASA/Goddard Space Flight Center, Greenbelt, MD (United States)); Maddox, R.A.; Howard, K.W. (NOAA/ERL National Severe Storms Laboratory, Norman, OK (United States)); Keehn, P.R. (Science Systems and Applications, Inc., Lanham, MD (United States))

    1993-11-01

    A three-year climatology of satellite-estimated rainfall for the warm season for the southwest United States and Mexico has been derived from data from the Special Sensor Microwave Imager (SSM/I). The microwave data have been stratified by month (June, July, August), year (1988, 1989, 1990), and time of day (morning and evening orbits). A rain algorithm was employed that relates 86-GHz brightness temperatures to rain rate using a coupled cloud-radiative transfer model. Results identify an early evening maximum in rainfall along the western slope of the Sierra Madre Occidental during all three months. A prominent morning rainfall maximum was found off the western Mexican coast near Mazatlan in July and August. Substantial differences between morning and evening estimates were noted. To the extent that three years constitute a climatology, results of interannual variability are presented. Results are compared and contrasted to high-resolution (8 km, hourly) infrared cloud climatologies, which consist of the frequency of occurrence of cloud colder than -38[degrees]C and -58[degrees]C. This comparison has broad implications for the estimation of rainfall by simple (cloud threshold) techniques. 18 refs., 44 figs.

  16. Sensitivity of a 30 year model climatology of Middle and Central America to resolution and atmosphere-ocean coupling

    Science.gov (United States)

    Quintanar, A. I.; Sein, D.; Martinez Lopez, B.

    2013-05-01

    A 30 year climatology experiment has been completed with a regional coupled atmosphere-ocean model (REMO) over a vast region that covers latitude-wise the Middle and Central Americas up to Western Europe. The control simulation uses a horizontal resolution of 1 degree and REMO was forced at its lateral walls with ERA data for the period 1979-2010. The ocean model was initialized using previously integrated solutions from an atmospherically forced only ocean simulation. In order to gauge the impact that the atmosphere-ocean coupling had, an identical experiment was performed with prescribed SST for the same period. A couple of identical experiments but with a resolution of 1/2 degree were also performed to investigate the effect of horizontal spatial resolution. It is seen that model climatology is increasingly closer to observed precipitation climatology (compared to CRU data for that period) as the model goes from a SST-forced condition to one of full coupling and from coarser resolution to increasing resolution as well. Of note, is the significantly better representation of the ITZC annual latitudinal excursion over the Eastern Pacific Ocean corresponding to the onset of monsoon precipitation season over western Mexico.

  17. 4.4 Development of a 30-Year Soil Moisture Climatology for Situational Awareness and Public Health Applications

    Science.gov (United States)

    Case, Jonathan L.; Zavodsky, Bradley T.; White, Kristopher D.; Bell, Jesse E.

    2015-01-01

    This paper provided a brief background on the work being done at NASA SPoRT and the CDC to create a soil moisture climatology over the CONUS at high spatial resolution, and to provide a valuable source of soil moisture information to the CDC for monitoring conditions that could favor the development of Valley Fever. The soil moisture climatology has multi-faceted applications for both the NOAA/NWS situational awareness in the areas of drought and flooding, and for the Public Health community. SPoRT plans to increase its interaction with the drought monitoring and Public Health communities by enhancing this testbed soil moisture anomaly product. This soil moisture climatology run will also serve as a foundation for upgrading the real-time (currently southeastern CONUS) SPoRT-LIS to a full CONUS domain based on LIS version 7 and incorporating real-time GVF data from the Suomi-NPP Visible Infrared Imaging Radiometer Suite (Vargas et al. 2013) into LIS-Noah. The upgraded SPoRT-LIS run will serve as a testbed proof-of-concept of a higher-resolution NLDAS-2 modeling member. The climatology run will be extended to near real-time using the NLDAS-2 meteorological forcing from 2011 to present. The fixed 1981-2010 climatology shall provide the soil moisture "normals" for the production of real-time soil moisture anomalies. SPoRT also envisions a web-mapping type of service in which an end-user could put in a request for either an historical or real-time soil moisture anomaly graph for a specified county (as exemplified by Figure 2) and/or for local and regional maps of soil moisture proxy percentiles. Finally, SPoRT seeks to assimilate satellite soil moisture data from the current Soil Moisture Ocean Salinity (SMOS; Blankenship et al. 2014) and the recently-launched NASA Soil Moisture Active Passive (SMAP; Entekhabi et al. 2010) missions, using the EnKF capability within LIS. The 9-km combined active radar and passive microwave retrieval product from SMAP (Das et al. 2011

  18. Dynamical climatology of the NASA Langley Research Center Interactive Modeling Project for Atmospheric Chemistry and Transport (IMPACT) model

    Science.gov (United States)

    Pierce, R. Bradley; Al-Saadi, Jassim A.; Eckman, Richard S.; Fairlie, T. Duncan; Grose, William L.; Kleb, Mary M.; Natarajan, Murali; Olson, Jennifer R.

    2000-12-01

    A comparison of the NASA Langley Research Center (LaRC) Interactive Modeling Project for Atmospheric Chemistry and Transport (IMPACT) model's dynamical characteristics with assimilated data sets and observations is presented to demonstrate the ability of the model to represent the dynamical characteristics of Earth's troposphere and stratosphere. The LaRC IMPACT model is a coupled chemical/dynamical general circulation model (GCM) of the Earth's atmosphere extending from the surface to the lower mesosphere. It has been developed as a tool for assessing the effects of chemical, dynamical, and radiative coupling in the stratosphere on the Earth's climate. The LaRC IMPACT model winds and temperatures are found to be in fairly good agreement with Upper Atmospheric Research Satellite (UARS) United Kingdom Meteorological Office (UKMO) assimilated winds and temperatures in the lower stratosphere. The model upper stratospheric zonal mean temperatures are also in good agreement with the UARS-UKMO climatology except for a cold winter pole which results from the upward extension of the cold vortex temperatures and an elevated winter stratopause in the model. The cold pole bias is consistent with the overprediction of the winter stratospheric jet strength, and is characteristic of stratospheric GCMs in general. The model northern and southern hemisphere stratospheric eddy heat and momentum fluxes are within the expected interannual variability of the UARS-UKMO climatology. The combined effects of water vapor transport, radiative, convective, and planetary boundary layer parameterizations are shown to produce tropospheric winds and circulation statistics that are in good agreement with the UARS-UKMO climatology, although the model tropopause and upper tropospheric temperatures are generally cold relative to the UARS-UKMO temperatures. Comparisons between the model and UARS-UKMO climatology indicate that the model does a reasonable job in reproducing the frequency of observed

  19. New and Updated Gridded Analysis Products provided by the Global Precipitation Climatology Centre (GPCC)

    Science.gov (United States)

    Ziese, Markus; Schneider, Udo; Meyer-Christoffer, Anja; Finger, Peter; Schamm, Kirstin; Rustemeier, Elke; Becker, Andreas

    2016-04-01

    Since its start in 1989 the Global Precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth's land-surface on the basis of in-situ measurements. Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The high spatio-temporal variability of precipitation requires an accordingly high density of measurement data. Data collected from national meteorological and hydrological services are the core of the GPCC data base, supported by global and regional data collections. Also the GPCC receives SYNOP and CLIMAT reports via WMO-GTS, which are mainly applied for near-real-time products. A high quality control effort is undertaken to remove miscoded and temporal or spatial dislocated data before entry into the GPCC archive, serving the basis for further interpolation and product generation. The GPCC archive holds records from almost 100 000 stations, among those three quarters with records long enough to serve the data basis of the GPCC suite of global precipitation products, comprising near-real-time as well as non-real-time products. Near-real-time products are the 'First Guess Monthly', 'First Guess Daily', 'Monitoring Product' and 'GPCC Drought Index'. These products are based on WMO-GTS data, e.g., SYNOP and CLIMAT reports and monthly totals calculated at CPC. Non-real-time products are the 'Full Data Monthly', 'Full Data Daily', 'Climatology', and 'HOMPRA-Europe'. Data from national meteorological and hydrological services and regional and global data collections are mainly used to calculate these products. Also WMO-GTS data are used if no other data are available. The majority of the products were released in an updated version, but 'Full Data Daily' and HOMPRA-Europe' are new products provided the first time. 'Full Data Daily' is a global analysis of daily precipitation totals from 1988 to 2013

  20. Carbon monoxide climatology derived from the trajectory mapping of global MOZAIC-IAGOS data

    Science.gov (United States)

    Osman, Mohammed K.; Tarasick, David W.; Liu, Jane; Moeini, Omid; Thouret, Valerie; Fioletov, Vitali E.; Parrington, Mark; Nédélec, Philippe

    2016-08-01

    A three-dimensional gridded climatology of carbon monoxide (CO) has been developed by trajectory mapping of global MOZAIC-IAGOS in situ measurements from commercial aircraft data. CO measurements made during aircraft ascent and descent, comprising nearly 41 200 profiles at 148 airports worldwide from December 2001 to December 2012, are used. Forward and backward trajectories are calculated from meteorological reanalysis data in order to map the CO measurements to other locations and so to fill in the spatial domain. This domain-filling technique employs 15 800 000 calculated trajectories to map otherwise sparse MOZAIC-IAGOS data into a quasi-global field. The resulting trajectory-mapped CO data set is archived monthly from 2001 to 2012 on a grid of 5° longitude × 5° latitude × 1 km altitude, from the surface to 14 km altitude.The mapping product has been carefully evaluated, firstly by comparing maps constructed using only forward trajectories and using only backward trajectories. The two methods show similar global CO distribution patterns. The magnitude of their differences is most commonly 10 % or less and found to be less than 30 % for almost all cases. Secondly, the method has been validated by comparing profiles for individual airports with those produced by the mapping method when data from that site are excluded. While there are larger differences below 2 km, the two methods agree very well between 2 and 10 km with the magnitude of biases within 20 %. Finally, the mapping product is compared with global MOZAIC-IAGOS cruise-level data, which were not included in the trajectory-mapped data set, and with independent data from the NOAA aircraft flask sampling program. The trajectory-mapped MOZAIC-IAGOS CO values show generally good agreement with both independent data sets.Maps are also compared with version 6 data from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. Both data sets clearly show major regional CO sources such

  1. Climatology of yellow sand (Asian sand, Asian dust or Kosa)in East Asia

    Institute of Scientific and Technical Information of China (English)

    Masatoshi; Yoshino

    2002-01-01

    In order to study climatology of yellow sand (Asian sand, Asian dust or Kosa) in EastAsia, secular fluctuation in China, Korea and Japan in the recent 30 years was presented. Thenumber of days with sand-dust storm at five stations in China-Hotan, Zhangye, Minqin, Jurhand Beijing, decreases a lot at the former three stations, but changed little at the latter two stations.Suggesting that the recent global warming is more evident in Xinjiang and Gansu, where the fre-quency of cold air invasions from the higher latitudes is decreasing. But, the eastern parts ofMongolia, inner Mongolia, and North China encounter stronger cyclones in early spring as a resultof global warming. These cyclones bring cold air from higher latitudes, causing severe duststorms. Secular variation in the annual days with sand-dust storms in China and Kosa days in Ko-rea and Japan show a parallel change with higher frequency from 1975 to 1985. This may be re-lated to the higher frequency of La Nina years. However, different tendency was shown in theperiod from 1986 to 1996. Since 1996 or 1997, a sharp increase is clear, which may be caused bythe developed cyclones in East Asia as well as human activities, and stronger land degradationunder La Nina conditions. Anomalies of the total number of stations with Kosa days were dis-cussed in accordance with some synoptic meteorological conditions such as the differences be-tween Siberian anticyclone and Aleutian cyclone center at 500 hPa level during the previous winter.

  2. Predictions of barrier island berm evolution in a time-varying storm climatology

    Science.gov (United States)

    Plant, Nathaniel G.; Flocks, James; Stockdon, Hilary F.; Long, Joseph W.; Guy, Kristy K.; Thompson, David M.; Cormier, Jamie M.; Smith, Christopher G.; Miselis, Jennifer L.; Dalyander, P. Soupy

    2014-01-01

    Low-lying barrier islands are ubiquitous features of the world's coastlines, and the processes responsible for their formation, maintenance, and destruction are related to the evolution of smaller, superimposed features including sand dunes, beach berms, and sandbars. The barrier island and its superimposed features interact with oceanographic forces (e.g., overwash) and exchange sediment with each other and other parts of the barrier island system. These interactions are modulated by changes in storminess. An opportunity to study these interactions resulted from the placement and subsequent evolution of a 2 m high sand berm constructed along the northern Chandeleur Islands, LA. We show that observed berm length evolution is well predicted by a model that was fit to the observations by estimating two parameters describing the rate of berm length change. The model evaluates the probability and duration of berm overwash to predict episodic berm erosion. A constant berm length change rate is also predicted that persists even when there is no overwash. The analysis is extended to a 16 year time series that includes both intraannual and interannual variability of overwash events. This analysis predicts that as many as 10 or as few as 1 day of overwash conditions would be expected each year. And an increase in berm elevation from 2 m to 3.5 m above mean sea level would reduce the expected frequency of overwash events from 4 to just 0.5 event-days per year. This approach can be applied to understanding barrier island and berm evolution at other locations using past and future storm climatologies.

  3. Exploring Climatology and Long-Term Variations of Aerosols from NASA Reanalysis MERRA-2 with Giovanni

    Science.gov (United States)

    Shen, Suhung; Ostrenga, Dana; Vollmer, Bruce; Li, Zhanqing

    2016-01-01

    Dust plays important roles in energy cycle and climate variations. The dust deposition is the major source of iron in the open ocean, which is an essential micronutrient for phytoplankton growth and therefore may influence the ocean uptake of atmospheric CO2. Mineral dust can also act as fertilizer for forests over long time periods. Over 35 years of simulated global aerosol products from NASA atmospheric reanalysis, second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) are available from NASA Goddard Earth Science Data and Information Services Center (GES DISC). The MERRA-2 covers the period 1980-present, continuing as an ongoing climate analysis. Aerosol assimilation is included throughout the period, using MODIS, MISR, AERONET, and AVHRR (in the pre-EOS period). The aerosols are assimilated by using MERRA-2 aerosol model, which interact directly with the radiation parameterization, and radiatively coupled with atmospheric model dynamics in the Goddard Earth Observing System Model, Version 5 (GEOS-5). Dust deposition data along with other major aerosol compositions (e.g. black carbon, sea salt, and sulfate, etc.) are simulated as dry and wet deposition, respectively. The hourly and monthly data are available at spatial resolution of 0.5ox0.625o (latitude x longitude). Quick data exploration of climatology and interannual variations of MERRA-2 aerosol can be done through the online visualization and analysis tool, Giovanni. This presentation, using dust deposition as an example, demonstrates a number of MERRA-2 data services at GES DISC. Global distributions of dust depositions, and their seasonal and inter-annual variations are investigated from MERRA-2 monthly aerosol products.

  4. Simulation of Sea Ice in FGOALS-g2: Climatology and Late 20th Century Changes

    Institute of Scientific and Technical Information of China (English)

    XU Shiming; SONG Mirong; LIU Jiping; WANG Bin; LI Lijuan; HUANG Wenyu; LIU Li

    2013-01-01

    Sea ice is an important component in the Earth's climate system.Coupled climate system models are indispensable tools for the study of sea ice,its internal processes,interaction with other components,and projection of future changes.This paper evaluates the simulation of sea ice by the Flexible Global Ocean-Atmosphere-Land System model Grid-point Version 2 (FGOALS-g2),in the fifth phase of the Coupled Model Inter-comparison Project (CMIP5),with a focus on historical experiments and late 20th century simulation.Through analysis,we find that FGOALS-g2 produces reasonable Arctic and Antarctic sea ice climatology and variability.Sea ice spatial distribution and seasonal change characteristics are well captured.The decrease of Arctic sea ice extent in the late 20th century is reproduced in simulations,although the decrease trend is lower compared with observations.Simulated Antarctic sea ice shows a reasonable distribution and seasonal cycle with high accordance to the amplitude of winter summer changes.Large improvement is achieved as compared with FGOALS-g1.0 in CMIP3.Diagnosis of atmospheric and oceanic forcing on sea ice reveals several shortcomings and major aspects to improve upon in the future:(1) ocean model improvements to remove the artificial island at the North Pole;(2) higher resolution of the atmosphere model for better simulation of important features such as,among others,the Icelandic Low and westerly wind over the Southern Ocean; and (3) ocean model improvements to accurately receive freshwater input from land,and higher resolution for resolving major water channels in the Canadian Arctic Archipelago.

  5. Seasonal patterns of water storage as signatures of the climatological equilibrium between resource and demand

    Science.gov (United States)

    François, B.; Hingray, B.; Hendrickx, F.; Creutin, J. D.

    2014-09-01

    Water is accumulated in reservoirs to adapt in time the availability of the resource to various demands like hydropower production, irrigation, water supply or ecological constraints. Deterministic dynamic programming retrospectively optimizes the use of the resource during a given time period. One of its by-products is the estimation of the marginal storage water value (MSWV), defined by the marginal value of the future goods and benefits obtained from an additional unit of storage water volume. Knowledge of the MSWV makes it possible to determine a posteriori the storage requirement scheme that would have led to the best equilibrium between the resource and the demand. The MSWV depends on the water level in the reservoir and shows seasonal as well as inter-annual variations. This study uses the inter-annual average of both the storage requirement scheme and the MSWV cycle as signatures of the best temporal equilibrium that is achievable in a given resource/demand context (the climatological equilibrium). For a simplified water resource system in a French mountainous region, we characterize how and why these signatures change should the climate and/or the demand change, mainly if changes are projected in the mean regional temperature (increase) and/or precipitation (decrease) as well as in the water demand for energy production and/or maintenance of a minimum reservoir level. Results show that the temporal equilibrium between water resource and demand either improves or degrades depending on the considered future scenario. In all scenarios, the seasonality of MSWV changes when, for example, earlier water storage is required to efficiently satisfy increasing summer water demand. Finally, understanding how MSWV signatures change helps to understand changes in the storage requirement scheme.

  6. Tropopause Folds: Global Climatology and their Impact on Extreme Weather Events

    Science.gov (United States)

    Skerlak, B.; Sprenger, M.; Pfahl, S.; Wernli, H.

    2014-12-01

    Folded structures in the tropopause, so-called tropopause folds, are intimately linked to upper-level frontogenesis and jet-stream dynamics. They play an important role for stratosphere-troposphere exchange, the dynamical coupling of upper- and lower troposphere, and can be important for generating severe weather events. Together with the filamentation and roll-up of streamers and the formation of cut-off lows, tropopause folds are a prime example for the complex dynamical structure of the UTLS on time scales from hours to days. For case studies, in-situ data or detailed manual analysis of model output often allow for an unambiguous identification of the tropopause. Obtaining a global, long-term perspective of this phenomenon, however, requires an automated and objective identification method. We present an elaborated three-dimensional labelling algorithm, based on an isosurface of potential vorticity (PV), that allows to objectively separate stratospheric and tropospheric air in complex situations in polar regions and in situations with diabatically and/or frictionally generated PV anomalies typically found near extratropical cyclones. We apply this algorithm to the ERA-Interim reanalysis data set from 1979 to 2012 to compile a robust global climatology of tropopause folds. We present geographical and seasonal distributions of fold frequencies for three classes of folds as defined by their vertical extent (shallow, medium and deep). Typical synoptic situations associated with deep tropopause folds like cyclonically curved jets are discussed and we investigate their potential impact on extreme weather events. For example, the frequency of wind speed extremes at 700 hPa is in many areas significantly higher if a tropopause fold is present.

  7. Tropopause folds in ERA-Interim: Global climatology and relation to extreme weather events

    Science.gov (United States)

    Škerlak, Bojan; Sprenger, Michael; Pfahl, Stephan; Tyrlis, Evangelos; Wernli, Heini

    2015-05-01

    Tropopause folds are intimately linked to upper level frontogenesis and jet stream dynamics. They play an important role for stratosphere-troposphere exchange, the dynamical coupling of upper and lower tropospheric levels, and for generating severe weather events. This study presents a global climatology of tropopause folds using ERA-Interim reanalysis data from 1979 to 2012 and a refined version of a previously developed 3-D labeling and fold identification algorithm. This algorithm objectively separates stratospheric and tropospheric air in complex situations, e.g., in regions with strong low-level inversions, and in extratropical cyclones where diabatically generated potential vorticity anomalies typically occur. Three classes of tropopause folds are defined (shallow, medium, and deep), and their geographical distribution, vertical extent, and seasonal cycle are investigated. Most shallow folds occur along the subtropical jet stream, in agreement with previous studies. Hot spots of medium and deep tropopause folds are found west of Australia and along the coast of Antarctica in the Southern Hemisphere and around the east coast of North America in the Northern Hemisphere. Seasonal cycles show maxima in winter for all fold classes. Medium and deep folds are frequently associated with surface wind gust and precipitation extremes, as quantified for folds over the southern Indian Ocean. Wind gust extremes occur mainly in an elongated band upstream and equatorward of folds, whereas precipitation extremes occur mainly east and poleward of folds. Overall, in the considered region, about 20% of medium folds and 33% of deep folds are associated with surface wind or precipitation extremes in the vicinity of the fold.

  8. A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part III: Radiative Properties

    Energy Technology Data Exchange (ETDEWEB)

    Sassen, K.; Comstock, Jennifer M.

    2001-08-01

    In Part III of a series of papers describing the extended time high-cloud observations from the University of Utah Facility for Atmospheric Remote Sensing (FARS) supporting the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment, the visible and infrared radiative properties of cirrus clouds over Salt Lake City, Utah, are examined. Using {approx}860 h of combined ruby (0.694 {micro}m) lidar and midinfrared (9.5-11.5 {micro}m) radiometer data collected between 1992 and 1999 from visually identified cirrus clouds, the visible optical depths {tau} and infrared layer emittance epsilon of the varieties of midlatitude cirrus are characterized. The mean and median values for the cirrus sample are 0.75 {+-} 0.91 and 0.61 for {tau}, and 0.30 {+-} 0.22 and 0.25 for epsilon. Other scattering parameters studied are the visible extinction and infrared absorption coefficients, and their ratio, and the lidar backscatter-to-extinction ratio, which has a mean value of 0.041 sr{sup -1}. Differences among cirrus clouds generated by general synoptic (e.g., jet stream), thunderstorm anvil, and orographic mechanisms are found, reflecting basic cloud microphysical effects. The authors draw parameterizations in terms of midcloud temperature T{sub m} and physical cloud thickness {Delta}z for epsilon and {tau}: both macrophysical variables are needed to adequately address the impact of the adiabatic process on ice cloud content, which modulates radiative transfer as a function of temperature. For the total cirrus dataset, the authors find epsilon = 1 -exp [-8.5 x 10{sup -5} (T{sub m} + 80 C) {Delta}z]. These parameterizations, based on a uniquely comprehensive dataset, hold the potential for improving weather and climate model predictions, and satellite cloud property retrieval methods.

  9. Quantifying the occurrence and magnitude of the Southeast Asian fire climatology

    International Nuclear Information System (INIS)

    Current emissions inventories of black carbon aerosol, an important component of PM2.5 and a powerful climate altering species, are highly uncertain in both space and time. One of the major and hardest to constrain sources of black carbon is fire, which comes from a combination of forest, vegetation, agricultural, and peat sources. Therefore, quantifying this source more precisely in both space and time is essential. While there is a growing body of work on this topic, the best estimations generally underestimate measurements by integer factors. In this work, 12 years of measurements from 2000 through 2012 of AOD from the MISR satellite and AOD and AAOD from the AERONET network, are used to evaluate the aerosol climatology from Southeast Asian fires. First, the fires in Southeast Asia are uniquely characterized in both space and time to reveal two major burning regions: one with a regular inter-annual and intra-annual distribution, and the other with an irregular inter-annual and somewhat variable intra-annual distribution. These patterns correspond well with regional and local measurements of both composition and meteorology. Using these newly developed relationships, a new temporally and spatially varying set of black carbon emissions is developed. Finally, the best fits with the various measurements yield an annual average value for black carbon emissions due to fires bounded by the range 0.36–0.54 Tg yr−1, with the amount in the year of the greatest fires being bounded by the range 1.2–1.8 Tg yr−1. These magnitudes are significantly higher and differently distributed in space and time when compared with current inventories, and therefore are expected to have a significant impact on regional particulate loadings and the global climate system. (letter)

  10. Jet characterization in the upper troposphere/lower stratosphere (UTLS: applications to climatology and transport studies

    Directory of Open Access Journals (Sweden)

    G. L. Manney

    2011-01-01

    Full Text Available A method of classifying the upper tropospheric/lower stratospheric (UTLS jets has been developed that allows satellite and aircraft trace gas data and meteorological fields to be efficiently mapped in a jet coordinate view. A detailed characterization of multiple tropopauses accompanies the jet characterization. Jet climatologies show the well-known high altitude subtropical and lower altitude polar jets in the upper troposphere, as well as a pattern of concentric polar and subtropical jets in the Southern Hemisphere, and shifts of the primary jet to high latitudes associated with blocking ridges in Northern Hemisphere winter. The jet-coordinate view segregates air masses differently than the commonly-used equivalent latitude (EqL coordinate throughout the lowermost stratosphere and in the upper troposphere. Mapping O3 data from the Aura Microwave Limb Sounder (MLS satellite and the Winter Storms aircraft datasets in jet coordinates highlights important advantages in comparison to an EqL-coordinate view: strong PV, tropopause height and trace gas gradients across the subtropical jet are washed out in the latter and clearly highlighted in the former. The jet coordinate view emphasizes the presence of stratospheric ozone well below the tropopause, especially poleward of and below the jet core, and highlights other transport features associated with the upper tropospheric jets. MLS and Atmospheric Chemistry Experiment-Fourier Transform Spectrometer trace gas fields for spring 2008 in jet coordinates show very strong, closely correlated, PV, tropopause height and trace gas gradients across the jet, and evidence of intrusions of stratospheric air below the tropopause below and poleward of the subtropical jet; these features are consistent between instruments and among multiple trace gases. Our characterization of the jets is facilitating studies that will improve our understanding of upper tropospheric trace gas evolution.

  11. European drought climatologies and trends based on a multi-indicator approach

    Science.gov (United States)

    Spinoni, Jonathan; Naumann, Gustavo; Vogt, Jürgen; Barbosa, Paulo

    2015-04-01

    Drought is one of the most important weather-induced phenomena which may have severe impacts on different areas such as agriculture, economy, energy production, and society. From a meteorological point of view, drought can be induced and/or reinforced by lack of precipitation, hot temperatures and enhanced evapotranspiration. Starting from a multi-indicator approach, we present European-wide meteorological drought climatologies and trends for the period 1950-2012. As input data, we used precipitation and temperature data from the E-OBS (spatial resolution: 0.25° × 0.25°) gridded dataset of the European Climate Assessment and Dataset (ECA&D). Precipitation, temperature, and the derived potential evapotranspiration (PET) have been used to compute three drought indicators: the Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), and the Reconnaissance Drought Index (RDI). SPI, SPEI, and RDI, calculated for 12-month accumulation period, have been rationally merged into a combined indicator and this quantity has been used to obtain drought frequency, duration, and severity for the entire Europe. We identified the following drought hotspots: Scandinavia, Eastern Europe, and Russia in 1951-1970, no particular hotspot in 1971-1990, the Mediterranean region and the Baltic Republics in 1991-2010. A linear trend analysis shows that drought variables increased in the period 1950-2012 in South-Western Europe, in particular in the Mediterranean and Carpathian regions, with precipitation decrease and PET increase as drivers. Drought variables show a decrease in Scandinavia, Belarus, Ukraine and Russia: precipitation increase is the main driver. In Central Europe and the Balkans, drought variables show a moderate increase, for the significant PET increase outbalances a not significant precipitation increase.

  12. Replacing climatological potential evapotranspiration estimates with dynamic satellite-based observations in operational hydrologic prediction models

    Science.gov (United States)

    Franz, K. J.; Bowman, A. L.; Hogue, T. S.; Kim, J.; Spies, R.

    2011-12-01

    In the face of a changing climate, growing populations, and increased human habitation in hydrologically risky locations, both short- and long-range planners increasingly require robust and reliable streamflow forecast information. Current operational forecasting utilizes watershed-scale, conceptual models driven by ground-based (commonly point-scale) observations of precipitation and temperature and climatological potential evapotranspiration (PET) estimates. The PET values are derived from historic pan evaporation observations and remain static from year-to-year. The need for regional dynamic PET values is vital for improved operational forecasting. With the advent of satellite remote sensing and the adoption of a more flexible operational forecast system by the National Weather Service, incorporation of advanced data products is now more feasible than in years past. In this study, we will test a previously developed satellite-derived PET product (UCLA MODIS-PET) in the National Weather Service forecast models and compare the model results to current methods. The UCLA MODIS-PET method is based on the Priestley-Taylor formulation, is driven with MODIS satellite products, and produces a daily, 250m PET estimate. The focus area is eight headwater basins in the upper Midwest U.S. There is a need to develop improved forecasting methods for this region that are able to account for climatic and landscape changes more readily and effectively than current methods. This region is highly flood prone yet sensitive to prolonged dry periods in late summer and early fall, and is characterized by a highly managed landscape, which has drastically altered the natural hydrologic cycle. Our goal is to improve model simulations, and thereby, the initial conditions prior to the start of a forecast through the use of PET values that better reflect actual watershed conditions. The forecast models are being tested in both distributed and lumped mode.

  13. NO2 climatology in the northern subtropical region: diurnal, seasonal and interannual variability

    Directory of Open Access Journals (Sweden)

    M. Navarro

    2007-10-01

    Full Text Available Daily NO2 vertical column density (VCD has been routinely measured by zenith sky spectroscopy at the subtropical station of Izaña (28° N, 16° W since 1993 in the framework of the Network for the Detection of Atmospheric Composition Change (NDACC. Based on 14 years of data the first low latitudes NO2 VCD climatology has been established and the main characteristics from short scales of one day to inter-annual variability are presented. Instrumental descriptions and different source of errors are described in detail. The observed diurnal cycle follows that expected by gas-phase NOx chemistry, as can be shown by the good agreement with a vertically integrated chemical box model, and is modulated by solar radiation. The seasonal evolution departs from the phase of the hours of daylight, showing the signature of upper stratospheric temperature changes. From the data record no significant long-term trends in NO2 VCD can be inferred. Comparison of the ground-based data sets with nadir looking satellite spectrometers shows excellent agreement for SCIAMACHY with differences between both datasets of 1.1%. GOME displays unrealistic features with largest discrepancies during summer. The ground-based data are compared with long-term output of the SLIMCAT 3-D chemical transport model (CTM. The basic model, forced by ECMWF (ERA-40 analyses, captures the observed NO2 annual cycle but significantly underestimates the spring/summer maximum. In a model run which uses assimilation of satellite CH4 profiles to constrain the model long-lived tracers the agreement is significantly improved. This improvement in modelled column NO2 is due to better modelled NOy profiles and points to transport errors in the ECMWF ERA-40 reanalyses.

  14. Climatological study of ionospheric irregularities over the European mid-latitude sector with GPS

    Science.gov (United States)

    Wautelet, Gilles; Warnant, René

    2014-03-01

    High-frequency variability of the ionosphere, or irregularities, constitutes the main threat for real-time precise positioning techniques based on Global Navigation Satellite Systems (GNSS) measurements. Indeed, during periods of enhanced ionospheric variability, GNSS users in the field—who cannot verify the integrity of their measurements—will experience positioning errors that can reach several decimeters, while the nominal accuracy of the technique is cm-level. In the frame of this paper, a climatological analysis of irregularities over the European mid-latitude region is presented. Based on a 10 years GPS dataset over Belgium, the work analyzes the occurrence rate (as a function of the solar cycle, season and local time) as well as the amplitude of ionospheric irregularities observed at a single GPS station. The study covers irregularities either due to space weather events (solar origin) or of terrestrial origin. If space weather irregularities are responsible for the largest effects in terms of ionospheric error, their occurrence rate highly depends on solar activity. Indeed, the occurrence rate of ionospheric irregularities is about 9 % during solar maximum, whereas it drops to about 0 % during medium or low solar activity periods. Medium-scale ionospheric disturbances (MSTIDs) occurring during daytime in autumn/winter are the most recurrent pattern of the time series, with yearly proportions slightly varying with the solar cycle and an amplitude of about 10 % of the TEC background. Another recurrent irregularity type, though less frequent than MSTIDs, is the noise-like variability in TEC observed during summer nighttime, under quiet geomagnetic conditions. These summer nighttime irregularities exhibit amplitudes ranging between 8 and 15 % of the TEC background.

  15. Detection of Atmospheric Rivers: An Algorithm for Global Climatology and Model Evaluation Studies

    Science.gov (United States)

    Guan, B.; Waliser, D. E.

    2015-12-01

    Atmospheric rivers (ARs) are narrow, elongated, synoptic jets of water vapor that play important roles in the global water cycle and regional weather and hydrology. Previous studies have developed techniques for the identification of ARs based on intensity and/or geometry thresholds indicative of AR conditions. Such techniques have facilitated the investigation of ARs on local to regional scales. Recent advancement in the understanding of AR's global signatures and impacts (including those in less explored areas such as Greenland and Antarctica), and the need for understanding the representation of key AR characteristics in global weather/climate models motivate the development and evaluation of AR detection techniques suitable for global climatological and model evaluation studies. In this work, an objective AR detection algorithm is developed based on thresholding global, 6-hourly fields of integrated water vapor transport (IVT) derived from ERA-Interim reanalysis. Long, narrow filaments of enhanced IVT are detected by applying a set of intensity and geometry criteria, along with other considerations. Key output of the algorithm includes the AR shape boundary, main axis, location of landfalls, and a tabulated list of the basic statistics such as length, width, and mean IVT strength/direction of each detected AR. Sensitivity of detection is examined for selected parameters, and the result is evaluated and compared with an independent database of landfalling ARs in the west coast of North America based on satellite images of integrated water vapor (Neiman et al. 2008). Global distribution of key AR characteristics, and examples of their modulation by climate variability, will be presented.

  16. United States Historical Climatology Network Daily Temperature and Precipitation Data (1871-1997)

    Energy Technology Data Exchange (ETDEWEB)

    Easterling, D.R.

    2002-10-28

    This document describes a database containing daily observations of maximum and minimum temperature, precipitation amount, snowfall amount, and snow depth from 1062 observing stations across the contiguous US. This database is an expansion and update of the original 138-station database previously released by the Carbon Dioxide Information Analysis Center (CDIAC) as CDIAC numeric data package NDP-042. These 1062 stations are a subset of the 1221-station US Historical Climatology Network (HCN), a monthly database compiled by the National Climatic Data Center (Asheville, North Carolina) that has been widely used in analyzing US climate. Data from 1050 of these daily records extend into the 1990s, while 990 of these extend through 1997. Most station records are essentially complete for at least 40 years; the latest beginning year of record is 1948. Records from 158 stations begin prior to 1900, with that of Charleston, South Carolina beginning the earliest (1871). The daily resolution of these data makes them extremely valuable for studies attempting to detect and monitor long-term climatic changes on a regional scale. Studies using daily data may be able to detect changes in regional climate that would not be apparent from analysis of monthly temperature and precipitation data. Such studies may include analyses of trends in maximum and minimum temperatures, temperature extremes, daily temperature range, precipitation ''event size'' frequency, and the magnitude and duration of wet and dry periods. The data are also valuable in areas such as regional climate model validation and climate change impact assessment. This database is available free of charge from CDIAC as a numeric data package (NDP).

  17. Precipitation climatology over India: validation with observations and reanalysis datasets and spatial trends

    Science.gov (United States)

    Kishore, P.; Jyothi, S.; Basha, Ghouse; Rao, S. V. B.; Rajeevan, M.; Velicogna, Isabella; Sutterley, Tyler C.

    2016-01-01

    Changing rainfall patterns have significant effect on water resources, agriculture output in many countries, especially the country like India where the economy depends on rain-fed agriculture. Rainfall over India has large spatial as well as temporal variability. To understand the variability in rainfall, spatial-temporal analyses of rainfall have been studied by using 107 (1901-2007) years of daily gridded India Meteorological Department (IMD) rainfall datasets. Further, the validation of IMD precipitation data is carried out with different observational and different reanalysis datasets during the period from 1989 to 2007. The Global Precipitation Climatology Project data shows similar features as that of IMD with high degree of comparison, whereas Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation data show similar features but with large differences, especially over northwest, west coast and western Himalayas. Spatially, large deviation is observed in the interior peninsula during the monsoon season with National Aeronautics Space Administration-Modern Era Retrospective-analysis for Research and Applications (NASA-MERRA), pre-monsoon with Japanese 25 years Re Analysis (JRA-25), and post-monsoon with climate forecast system reanalysis (CFSR) reanalysis datasets. Among the reanalysis datasets, European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim) shows good comparison followed by CFSR, NASA-MERRA, and JRA-25. Further, for the first time, with high resolution and long-term IMD data, the spatial distribution of trends is estimated using robust regression analysis technique on the annual and seasonal rainfall data with respect to different regions of India. Significant positive and negative trends are noticed in the whole time series of data during the monsoon season. The northeast and west coast of the Indian region shows significant positive trends and negative trends over western Himalayas and

  18. Climatic effects on decomposing litter and substrate chemistry along climatological gradients.

    Science.gov (United States)

    Berg, B.

    2009-04-01

    Climatic effects on decomposing litter and substrate chemistry along climatological gradients. B. Berg, Dipartimento Biologia Strutturale e Funzionale, Complesso Universitario, Monte San Angelo, via Cintia, I-80126 Napoli, Italy and Department of Forest Ecology, P.O. Box 27, University of Helsinki, FIN-00014, Helsinki, Finland. Studies of several processes, using climatic gradients do provide new information as compared with studies at e.g. a single site. Decomposition of plant litter in such gradients give response in decomposition rates to natural climate conditions. Thus Scots pine needle litter incubated in a climate gradient with annual average temperature (AVGT) ranging from -0.5 to 6.8oC had a highly significant increase in initial mass-loss rate with R2 = 0.591 (p<0.001) and a 5o increase in temperature doubled the mass-loss rate. As a contrast - needle litter of Norway spruce incubated in the same transect had no significant response to climate and for initial litter a 5o increase increased mass-loss rate c. 6%. For more decomposed Scots pine litter we could see that the effect of temperature on mass-loss rate gradually decreased until it disappeared. Long-term decomposition studies revealed differences in litter decomposition patterns along a gradient, even for the same type of litter. This could be followed by using an asymptotic function that gave, (i) a measure a maximum level of decomposition, (ii) the initial decomposition rate. Over a gradient the calculated maximum level of decomposition decreased with increasing AVGT. Other gradient studies revealed an effect of AVGT on litter chemical composition. Pine needle litter from stands under different climate conditions had nutrient concentrations related to AVGT. Thus N, P, K, and S were positively related to AVGT and Mn negatively, all of them significantly. This information may be used to explain the changing pattern in decomposition over the gradient.

  19. Climatology of monsoon precipitation over the Tibetan Plateau from 13-year TRMM observations

    Science.gov (United States)

    Aijuan, Bai; Guoping, Li

    2015-07-01

    Based on the 13-year data from the Tropical Rainfall Measuring Mission (TRMM) satellite during 2001-2013, the influencing geographical location of the Tibetan Plateau (Plateau) monsoon is determined. It is found that the domain of the Plateau monsoon is bounded by the latitude between 27° N and 37° N and the longitude between 60° E and 103° E. According to the annual relative precipitation, the Plateau monsoon can be divided into three sections: the Plateau winter monsoon (PWM) over Iran and Afghanistan, the Plateau summer monsoon (PSM) over the central Plateau, and the transiting zone of the Plateau monsoon (TPM) over the south, west, and east edges of the Plateau. In PWM and PSM, the monsoon climatology has a shorter rainy season with the mean annual rainfall of less than 800 mm. In TPM, it has a longer rainy season with the mean annual rainfall of more than 1800 mm. PWM experiences a single-peak monthly rainfall with the peak during January to March; PSM usually undergoes a multi-peak pattern with peaks in the warm season; TPM presents a double-peak pattern, with a strong peak in late spring to early summer and a secondary peak in autumn. The Plateau monsoon also characterizes an asymmetrical seasonal advance of the rain belt. In the east of the Plateau, the rain belt migrates in a south-north orientation under the impact of the tropical and subtropical systems' oscillation. In the west of the Plateau, the rain belt advances in an east-west direction, which is mainly controlled by the regional Plateau monsoon.

  20. Severe heat waves in Southern Australia: synoptic climatology and large scale connections

    Science.gov (United States)

    Pezza, Alexandre Bernardes; van Rensch, Peter; Cai, Wenju

    2012-01-01

    This paper brings a new perspective on the large scale dynamics of severe heat wave (HW) events that commonly affect southern Australia. Through an automatic tracking scheme, the cyclones and anticyclones associated with HWs affecting Melbourne, Adelaide and Perth are tracked at both the surface and upper levels, producing for the first time a synoptic climatology that reveals the broader connections associated with these extreme phenomena. The results show that a couplet (or pressure dipole) formed by transient cyclones and anticyclones can reinforce the HW similarly to what is observed in cold surges (CS), with an obvious opposite polarity. Our results show that there is a large degree of mobility in the synoptic signature associated with the passage of the upper level ridges before they reach Australia and the blocking is established, with HW-associated surface anticyclones often initiating over the west Indian Ocean and decaying in the eastern Pacific. In contrast to this result the 500 hPa anticyclone tracks show a very small degree of mobility, responding to the dominance of the upper level blocking ridge. An important feature of HWs is that most of the cyclones are formed inland in association with heat troughs, while in CS the cyclones are typically maritime (often explosive), associated with a strong cold front. Hence the influence of the cyclone is indirect, contributing to reinforce the blocking ridge through hot and dry advection on the ridge's western flank. Additional insights are drawn for the record Adelaide case of March 2008 with fifteen consecutive days above 35°C breaking the previous record by 7 days. Sea surface temperatures suggest a significant air-sea interaction mechanism, with a broad increase in the meridional temperature gradient over the Indian Ocean amplifying the upstream Rossby waves that can trigger HW events. A robust cooling of the waters close to the Australian coast also contributes to the maintenance of the blocking highs

  1. Climatology of observed rainfall in Southeast France at the Regional Climate Model scales

    Science.gov (United States)

    Froidurot, Stéphanie; Molinié, Gilles; Diedhiou, Arona

    2016-04-01

    In order to provide convenient data to assess rainfall simulated by Regional Climate Models, a spatial database (hereafter called K-REF) has been designed. This database is used to examine climatological features of rainfall in Southeast France, a study region characterized by two mountain ranges of comparable altitude (the Cévennes and the Alps foothill) on both sides of the Rhône valley. Hourly records from 1993 to 2013 have been interpolated to a 0.1° × 0.1° latitude-longitude regular grid and accumulated over 3-h periods in K-REF. The assessment of K-REF relatively to the SAFRAN daily rainfall reanalysis indicates consistent patterns and magnitudes between the two datasets even though K-REF fields are smoother. A multi-scale analysis of the occurrence and non-zero intensity of rainfall is performed and shows that the maps of the 50th and 95th percentiles of 3- and 24-h rain intensity highlight different patterns. The maxima of the 50th and 95th percentiles are located over plain and mountainous areas respectively. Moreover, the location of these maxima is not the same for the 3- and 24-h intensities. To understand these differences between median and intense rainfall on the one hand and between the 3- and 24-h rainfall on the other hand, we analyze the statistical distributions and the space-time structure of occurrence and intensity of the 3-h rainfall in two classes of days, defined as median and intense. This analysis illustrates the influence of two factors on the triggering and the intensity of rain in the region: the solar cycle and the orography. The orographic forcing appears to be quite different for the two ranges of the domain and is much more pronounced over the Cévennes.

  2. Climatological variations of total alkalinity and total inorganic carbon in the Mediterranean Sea surface waters

    Directory of Open Access Journals (Sweden)

    E. Gemayel

    2015-08-01

    Full Text Available A compilation of several cruises data from 1998 to 2013 was used to derive polynomial fits that estimate total alkalinity (AT and total inorganic carbon (CT from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross validation results and revealed that a second and third order polynomials fit the AT and CT data respectively. The AT surface fit showed an improved root mean square error (RMSE of ±10.6 μmol kg−1. Furthermore we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ±14.3 μmol kg−1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The seven years averages (2005–2012 mapped using the quarter degree climatologies of the World Ocean Atlas 2013 showed that in surface waters AT and CT have similar patterns with an increasing eastward gradient. The surface variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin, primarily due to the deepening of the mixed layer and upwelling of dense waters. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations.

  3. First climatology of polar mesospheric clouds from GOMOS/ENVISAT stellar occultation instrument

    Directory of Open Access Journals (Sweden)

    D. Fussen

    2009-11-01

    Full Text Available GOMOS (Global Ozone Monitoring by Occultation of Stars, on board the European platform ENVISAT launched in 2002, is a stellar occultation instrument combining four spectrometers and two fast photometers which measure light at 1 kHz sampling rate in the two visible channels 470–520 nm and 650–700 nm. On the day side, GOMOS does not measure only the light from the star, but also the solar light scattered by the atmospheric molecules. In the summer polar days, Polar Mesospheric Clouds (PMC are clearly detected using the photometers signals, as the solar light scattered by the cloud particles in the instrument field of view. The sun-synchronous orbit of ENVISAT allows observing PMC in both hemispheres and the stellar occultation technique ensures a very good geometrical registration. Four years of data, from 2002 to 2006, are analyzed up to now. GOMOS data set consists of approximately 10 000 cloud observations all over the eight PMC seasons studied. The first climatology obtained by the analysis of this data set is presented, focusing on the seasonal and latitudinal coverage, represented by global maps. GOMOS photometers allow a very sensitive PMC detection, showing a frequency of occurrence of 100% in polar regions during the middle of the PMC season. According to this work mesospheric clouds seem to be more frequent in the Northern Hemisphere than in the Southern Hemisphere. The PMC altitude distribution was also calculated. The obtained median values are 82.7 km in the North and 83.2 km in the South.

  4. Five-day back trajectory climatology for Rukomechi (Zambezi valley, Zimbabwe)

    Science.gov (United States)

    Nyanganyura, D.; Makarau, A.; Milford, J. R.; Mathuthu, M.; Helas, G.; Meixner, F. X.

    2003-04-01

    A five-year (1994-1999) back trajectory climatology has been established for Rukomechi Research Station/Zimbabwe (Zambezi Valley, 16^o 09' S, 29^o 26'E). Mixed layer air trajectories passing over Rukomechi are described in terms of directions of origin, wind speed, and inter- and intra annual periods of predominant flow. Trajectories show four possible source regions of air mass transport to Rukomechi: (1) northern Madagascar and Mozambique (with high winds during October/ November and low winds during December/January), (2) the Indian ocean south of Madagascar (with high and low winds during March and August/September, respectively), (3) the southern Atlantic and the tip of South Africa regions (with high winds during the middle of austral winter (June/July)), and (4) Zambia and Angola (bringing in mid-wet season air masses, which might carry the influence of the ITCZ). We also observed recirculating air masses which seem not to portray any season characteristics and which change year-by-year. The slow component of corridor (2) shows prevailing tendency, it is the main contributor of airflow to Rukomechi and it is dominant in the dry period (October to December). The year-to-year temporal variations show that 1997 was an abnormal year for the airflow over the research site. This has to be studied together with the variation in the meteorological parameters like rainfall during this period to find the influence of northern Zimbabwe air masses flows on the regional weather patterns. The importance of the presented classification is to narrow potential source regions of trace constituents and their most likely times of influence at Rukomechi througout the year on a monthly basis.

  5. Climatology and temporal evolution of the atmospheric semidiurnal tide in present-day reanalyses

    Science.gov (United States)

    Díaz-Argandoña, J.; Ezcurra, A.; Sáenz, J.; Ibarra-Berastegi, G.; Errasti, I.

    2016-05-01

    The solar semidiurnal atmospheric tide (S2) was extracted from seven reanalysis data sets, including current data sets, such as CFSR (Climate Forecast System Reanalysis), MERRA (Modern-Era Retrospective Analysis for Research and Applications), ERA-Interim (ECMWF Reanalysis), and 20CR (Twentieth Century Reanalysis), and older frozen products, such as NCEP/NCAR (National Center for Environmental Prediction/National Center for Atmospheric Research), ERA-40 (ECMWF Reanalysis), and JRA-25 (Japanese 25 year Reanalysis). In this calculation, we emphasized the temporal variation of the tide. We also calculated the tidal error, which was sizable at high latitudes and over short averaging periods and large for 20CR at all latitudes. Because of the four standard daily samples, the interpolation scheme of van den Dool et al. (1997) was used when necessary. We found this method to be accurate for zonally averaged tides only. Comparing the climatology from the MERRA and CFSR S2 with a recent empirical tide model showed that MERRA better represented the geographical structure of the tide, especially its phase. We found a bias in the phase in all of the reanalysis data sets except for MERRA. The temporal evolution of the tide was inconsistent between the different data sets, although similar seasonal variations were observed. The seasonal cycle was also better depicted in MERRA. The S2 calculated from MERRA and satellite precipitation measurements from TRMM (Tropical Rainfall Measuring Mission) presented results that were inconsistent with the hypothesis in which rainfall latent heat release represents S2 forcing and functions as a source of S2 seasonal variability.

  6. An analysis of the synoptic and climatological applicability of circulation type classifications for Ireland

    Science.gov (United States)

    Broderick, Ciaran; Fealy, Rowan

    2013-04-01

    Circulation type classifications (CTCs) compiled as part of the COST733 Action, entitled 'Harmonisation and Application of Weather Type Classifications for European Regions', are examined for their synoptic and climatological applicability to Ireland based on their ability to characterise surface temperature and precipitation. In all 16 different objective classification schemes, representative of four different methodological approaches to circulation typing (optimization algorithms, threshold based methods, eigenvector techniques and leader algorithms) are considered. Several statistical metrics which variously quantify the ability of CTCs to discretize daily data into well-defined homogeneous groups are used to evaluate and compare different approaches to synoptic typing. The records from 14 meteorological stations located across the island of Ireland are used in the study. The results indicate that while it was not possible to identify a single optimum classification or approach to circulation typing - conditional on the location and surface variables considered - a number of general assertions regarding the performance of different schemes can be made. The findings for surface temperature indicate that that those classifications based on predefined thresholds (e.g. Litynski, GrossWetterTypes and original Lamb Weather Type) perform well, as do the Kruizinga and Lund classification schemes. Similarly for precipitation predefined type classifications return high skill scores, as do those classifications derived using some optimization procedure (e.g. SANDRA, Self Organizing Maps and K-Means clustering). For both temperature and precipitation the results generally indicate that the classifications perform best for the winter season - reflecting the closer coupling between large-scale circulation and surface conditions during this period. In contrast to the findings for temperature, spatial patterns in the performance of classifications were more evident for

  7. Aerosol climatology over South Africa based on 10 years of Multiangle Imaging Spectroradiometer (MISR) data

    Science.gov (United States)

    Tesfaye, M.; Sivakumar, V.; Botai, J.; Mengistu Tsidu, G.

    2011-10-01

    In this paper, we present a detailed study of the spatial and seasonal aerosol climatology over South Africa (SA), based on Multiangle Imaging Spectroradiometer (MISR) data. We have used 10 years (2000-2009) of MISR monthly mean aerosol extinction (τext), absorption (τa) optical depths at 558 nm, Angstrom exponents in visible (VIS; 446-672 nm) and near-infrared (NIR; 672-866 nm) spectral bands, and the extracted spectral curvature. The study has shown that, in terms of aerosol load level spatial variation, SA can be classified into three parts: the upper, central, and lower, which illustrate high, medium, and low aerosol loadings, respectively. The results for the three parts of SA are presented in detail. The prevailing sources of aerosols are different in each part of SA. The lower part is dominated by the air mass transport from the surrounding marine environment and other SA or neighboring regions, while the central and upper parts are loaded through wind-ablated mineral dust and local anthropogenic activities. During the biomass burning seasons (July-September), the central part of SA is more affected than the rest of SA by the biomass-burning aerosols (based on τa, ˜20% higher than the rest of SA). In alignment with the observed higher values of τext, aerosol size distributions were found to be highly variable in the upper part of SA, which is due to the high population and the industrial/mining/agricultural activities in this area.

  8. Aerosol climatology over Nile Delta based on MODIS, MISR and OMI satellite data

    Science.gov (United States)

    Marey, H. S.; Gille, J. C.; El-Askary, H. M.; Shalaby, E. A.; El-Raey, M. E.

    2011-10-01

    Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the "black cloud" during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) at 550 nm were examined for the 10 yr period from 2000-2009. Significant monthly variability is observed in the AOD with maxima in April or May (~0.5) and October (~0.45), and a minimum in December and January (~0.2). Monthly mean values of UV Aerosol Index (UVAI) retrieved by the Ozone Monitoring Instrument (OMI) for 4 yr (2005-2008) exhibit the same AOD pattern. The carbonaceous aerosols during the black cloud periods are confined to the planetary boundary layer (PBL), while dust aerosols exist over a wider range of altitudes, as shown by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) aerosol profiles. The monthly climatology of Multi-angle Imaging SpectroRadiometer (MISR) data show that the aerosols during the black cloud periods are spherical with a higher percentage of small and medium size particles, whereas the spring aerosols are mostly large non-spherical particles. All of the results show that the air quality in Cairo and the Nile delta region is subject to a complex mixture of air pollution types, especially in the fall season, when biomass burning contributes to a background of urban pollution and desert dust.

  9. First climatology of polar mesospheric clouds from GOMOS/ENVISAT stellar occultation instrument

    Directory of Open Access Journals (Sweden)

    K. Pérot

    2010-03-01

    Full Text Available GOMOS (Global Ozone Monitoring by Occultation of Stars, on board the European platform ENVISAT launched in 2002, is a stellar occultation instrument combining four spectrometers and two fast photometers which measure light at 1 kHz sampling rate in the two visible channels 470–520 nm and 650–700 nm. On the day side, GOMOS does not measure only the light from the star, but also the solar light scattered by the atmospheric molecules. In the summer polar days, Polar Mesospheric Clouds (PMC are clearly detected using the photometers signals, as the solar light scattered by the cloud particles in the instrument field of view. The sun-synchronous orbit of ENVISAT allows observing PMC in both hemispheres and the stellar occultation technique ensures a very good geometrical registration. Four years of data, from 2002 to 2006, are analyzed up to now. GOMOS data set consists of approximately 10 000 cloud observations all over the eight PMC seasons studied. The first climatology obtained by the analysis of this data set is presented, focusing on the seasonal and latitudinal coverage, represented by global maps. GOMOS photometers allow a very sensitive PMC detection, showing a frequency of occurrence of 100% in polar regions during the middle of the PMC season. According to this work mesospheric clouds seem to be more frequent in the Northern Hemisphere than in the Southern Hemisphere. The PMC altitude distribution was also calculated. The obtained median values are 82.7 km in the North and 83.2 km in the South.

  10. Total ozone and Umkehr observations at Hoher Sonnblick 1994-2011: Climatology and extreme events

    Science.gov (United States)

    Fitzka, M.; Hadzimustafic, J.; Simic, S.

    2014-01-01

    Umkehr and total ozone measurements have been carried out at Hoher Sonnblick (47.05°N, 12.95°E; 3106 m above sea level) since 1994 with the Brewer MkIV #093 spectrophotometer. These measurements are used to investigate trends in total and vertically resolved ozone in the period 1994-2011 and for establishing an Umkehr climatology. A method to estimate daily thresholds for extreme events in total ozone (TO3) based on skewed log-Weibull distributions is presented and applied to the record. An analysis of the such defined extreme events reveals a significant decline in the number of low events, whereas the high events increased by about the same amount. However, no significant trend is observed in the magnitude of extreme events. Solar activity and equivalent effective stratospheric chlorine show weak to no correlation with vertically resolved ozone, presumably due to the record's limited extent, while tropopause pressure and quasi-biennial oscillation show a significant influence. Trend analysis of total and vertically resolved ozone indicates a significant increase in TO3 of 2.0% per decade since 1994, whereas no recovery is observed in the upper stratosphere. While ozone concentrations continue to decrease or stagnate in the upper stratosphere, the loss is overcompensated by large gains in the lowest layers during winter, leading to a significant overall increase in TO3. During events with extremely low TO3, the largest deficiencies are found in the bottommost layers with a marked seasonal component. The topmost layers mainly contribute to TO3 reductions during late winter and fall.

  11. Tropospheric ozone climatology over Beijing: analysis of aircraft data from the MOZAIC program

    Directory of Open Access Journals (Sweden)

    A. J. Ding

    2007-07-01

    Full Text Available Ozone (O3 profiles recorded over Beijing from 1995 to 2005 by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC program were analyzed to provide a first climatology of tropospheric O3 over Beijing and the North China Plains (NCPs, one of the most populated and polluted regions in China. A pooled method was adopted in the data analysis to reduce the influence of irregular sampling frequency. The tropospheric O3 over Beijing shows a seasonal and vertical distribution typical of mid-latitude locations in the Northern Hemisphere, but has higher daytime concentrations in the lower troposphere, when compared to New York City, Tokyo, and Paris at similar latitude. The tropospheric O3 over Beijing exhibits a common summer maximum and a winter minimum, with a broad summer maximum in the middle troposphere and a narrower early summer (June peak in the lower troposphere. Examination of meteorological and satellite data suggests that the lower tropospheric O3 maximum in June is a result of strong photochemical production, transport of regional pollution, and possibly also more intense burnings of biomass in Central-Eastern China. Trajectory analysis indicates that in summer the regional pollution sources from the NCPs, maybe mixed with urban plumes from Beijing, played important roles on the high O3 concentrations in the boundary layer, but had limited impact on the O3 concentrations in the middle troposphere. A comparison of the data recorded before and after 2000 reveals that O3 in the lower troposphere over Beijing had a strong positive trend (approximately 2% per year from 1995 to 2005 in contrast to a flat or a decreasing trend over Tokyo, New York City, and Paris, indicating worsening photochemical pollution in Beijing and the NCPs.

  12. Probing for suitable climatology to estimate the predictability of monsoon onset over Kerala (MOK), India

    Science.gov (United States)

    Pal, J.; Chaudhuri, S.; Mukherjee, S.; Chowdhury, A. Roy

    2016-07-01

    Inter-annual variability in the onset of monsoon over Kerala (MOK), India, is investigated using daily temperature; mean sea level pressure; winds at 850, 500 and 200 hPa pressure levels; outgoing longwave radiation (OLR); sea surface temperature (SST) and vertically integrated moisture content anomaly with 32 years (1981-2013) observation. The MOK is classified as early, delayed, or normal by considering the mean monsoon onset date over Kerala to be the 1st of June with a standard deviation of 8 days. The objective of the study is to identify the synoptic setup during MOK and comparison with climatology to estimate the predictability of the onset type (early, normal, or delayed) with 5, 10, and 15 days lead time. The study reveals that an enhanced convection observed over the Bay of Bengal during early MOK is found to shift over the Arabian Sea during delayed MOK. An intense high-pressure zone observed over the western south Indian Ocean during early MOK shifts to the east during delayed MOK. Higher tropospheric temperature (TT) over the western Equatorial Ocean during early MOK and lower TT over the Indian subcontinent intensify the land-ocean thermal contrast that leads to early MOK. The sea surface temperature (SST) over the Arabian Sea is observed to be warmer during delayed than early MOK. During early MOK, the source of 850 hPa southwesterly wind shifts to the west equatorial zone while a COL region has been found during delayed MOK at that level. The study further reveals that the wind speed anomaly at the 200-hPa pressure level coincides inversely with the anomaly of tropospheric temperature.

  13. Climatology of the HOPE-G global ocean general circulation model - Sea ice general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Legutke, S. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany); Maier-Reimer, E. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1999-12-01

    The HOPE-G global ocean general circulation model (OGCM) climatology, obtained in a long-term forced integration is described. HOPE-G is a primitive-equation z-level ocean model which contains a dynamic-thermodynamic sea-ice model. It is formulated on a 2.8 grid with increased resolution in low latitudes in order to better resolve equatorial dynamics. The vertical resolution is 20 layers. The purpose of the integration was both to investigate the models ability to reproduce the observed general circulation of the world ocean and to obtain an initial state for coupled atmosphere - ocean - sea-ice climate simulations. The model was driven with daily mean data of a 15-year integration of the atmosphere general circulation model ECHAM4, the atmospheric component in later coupled runs. Thereby, a maximum of the flux variability that is expected to appear in coupled simulations is included already in the ocean spin-up experiment described here. The model was run for more than 2000 years until a quasi-steady state was achieved. It reproduces the major current systems and the main features of the so-called conveyor belt circulation. The observed distribution of water masses is reproduced reasonably well, although with a saline bias in the intermediate water masses and a warm bias in the deep and bottom water of the Atlantic and Indian Oceans. The model underestimates the meridional transport of heat in the Atlantic Ocean. The simulated heat transport in the other basins, though, is in good agreement with observations. (orig.)

  14. NO2 climatology in the northern subtropical region: diurnal, seasonal and interannual variability

    Directory of Open Access Journals (Sweden)

    S. Rodríguez

    2008-03-01

    Full Text Available Daily NO2 vertical column density (VCD has been routinely measured by zenith sky spectroscopy at the subtropical station of Izaña (28° N, 16° W since 1993 in the framework of the Network for the Detection of Atmospheric Composition Change (NDACC. Based on 14 years of data the first low latitude NO2 VCD climatology has been established and the main characteristics from short timescales of one day to interannual variability are presented. Instrumental descriptions and different sources of errors are described in detail. The observed diurnal cycle follows that expected by gas-phase NOx chemistry, as can be shown by the good agreement with a vertically integrated chemical box model, and is modulated by solar radiation. The seasonal evolution departs from the phase of the hours of daylight, indicating the signature of upper stratospheric temperature changes. From the data record (1993–2006 no significant long-term trends in NO2 VCD can be inferred. Comparison of the ground-based data sets with nadir-viewing satellite spectrometers shows excellent agreement for SCIAMACHY with differences between both datasets of 1.1%. GOME displays unrealistic features with the largest discrepancies during summer. The ground-based data are compared with long-term output of the SLIMCAT 3-D chemical transport model (CTM. The basic model, forced by ECMWF (ERA-40 analyses, captures the observed NO2 annual cycle but significantly underestimates the spring/summer maximum (by 12% at sunset and up to 25% at sunrise. In a model run which uses assimilation of satellite CH4 profiles to constrain the model long-lived tracers the agreement is significantly improved. This improvement in modelled column NO2 is due to better modelled NOy profiles and points to transport errors in the ECMWF ERA-40 reanalyses.

  15. Aerosol climatology over Nile Delta based on MODIS, MISR and OMI satellite data

    Directory of Open Access Journals (Sweden)

    H. S. Marey

    2011-10-01

    Full Text Available Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the "black cloud" during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS aerosol optical depth (AOD at 550 nm were examined for the 10 yr period from 2000–2009. Significant monthly variability is observed in the AOD with maxima in April or May (~0.5 and October (~0.45, and a minimum in December and January (~0.2. Monthly mean values of UV Aerosol Index (UVAI retrieved by the Ozone Monitoring Instrument (OMI for 4 yr (2005–2008 exhibit the same AOD pattern. The carbonaceous aerosols during the black cloud periods are confined to the planetary boundary layer (PBL, while dust aerosols exist over a wider range of altitudes, as shown by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO aerosol profiles. The monthly climatology of Multi-angle Imaging SpectroRadiometer (MISR data show that the aerosols during the black cloud periods are spherical with a higher percentage of small and medium size particles, whereas the spring aerosols are mostly large non-spherical particles. All of the results show that the air quality in Cairo and the Nile delta region is subject to a complex mixture of air pollution types, especially in the fall season, when biomass burning contributes to a background of urban pollution and desert dust.

  16. Aerosol Climatology over Nile Delta based on MODIS, MISR and OMI satellite data

    Directory of Open Access Journals (Sweden)

    H. S. Marey

    2011-04-01

    Full Text Available Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the "black cloud" during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS aerosol optical depth (AOD at 550 nm were examined for the 10 yr 2000–2009. Significant monthly variability is observed with maxima in April or May (~0.5 and October (~0.45, and a minimum in December and January (~0.2. Monthly mean values of UV Aerosol Index (UVAI retrieved by the Ozone Monitoring Instrument (OMI for 4 yr (2005–2008 exhibit the same AOD pattern. The carbonaceous aerosols during the black cloud periods are confined to the planetary boundary layer (PBL, while dust aerosols exist over a wider range of altitudes, as shown by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO aerosol profiles. The monthly climatology of Multi-angle Imaging SpectroRadiometer (MISR data show that the aerosols during the black cloud periods are spherical with a higher percentage of small and medium size particles, whereas the spring aerosols are mostly large non-spherical particles. All of the results show that the air quality in Cairo and the Nile delta region is subject to a complex mixture of air pollution types, especially in the fall season, when biomass burning contributes to a background of urban pollution and desert dust.

  17. Climatología urbana por modificación antropogénica. Alteración del balance de energía natural / Urban climatology by anthropogenic modification. Alteration of the natural energy balance

    OpenAIRE

    Fuentes Pérez, Carlos Alberto

    2015-01-01

    La investigación valora el análisis climático histórico para establecer la temperatura y humedad relativa media, en contraste con la climatología urbana por modificación antropogénica estudio de caso, y su contribución de consigna fijado para invierno y verano que son las estaciones críticas. El procedimiento metodológico a implementar, apoya a los planificadores urbanos a no tener que participar científicamente para evaluar el emplazamiento térmico de sus proyectos y por lo tanto se puede...

  18. Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS data set

    Directory of Open Access Journals (Sweden)

    A. Jones

    2012-06-01

    Full Text Available The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS aboard the Canadian satellite SCISAT (launched in August 2003 was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC Chemistry-Climate Model Validation Activity. The ACE-FTS climatological data set is available through the ACE website.

  19. Surface and bottom temperature and salinity climatology along the continental shelf off the Canadian and U.S. East Coasts

    Science.gov (United States)

    Richaud, Benjamin; Kwon, Young-Oh; Joyce, Terrence M.; Fratantoni, Paula S.; Lentz, Steven J.

    2016-08-01

    A new hydrographic climatology has been created for the continental shelf region, extending from the Labrador shelf to the Mid-Atlantic Bight. The 0.2-degree climatology combines all available observations of surface and bottom temperature and salinity collected between 1950 and 2010 along with the location, depth and date of these measurements. While climatological studies of surface and bottom temperature and salinity have been presented previously for various regions along the Canadian and U.S. shelves, studies also suggest that all these regions are part of one coherent system. This study focuses on the coherent structure of the mean seasonal cycle of surface and bottom temperature and salinity and its variation along the shelf and upper slope. The seasonal cycle of surface temperature is mainly driven by the surface heat flux and exhibits strong dependency on latitude (r≈-0.9). The amplitude of the seasonal cycle of bottom temperature is rather dependent on the depth, while the spatial distribution of bottom temperature is correlated with latitude. The seasonal cycle of surface salinity is influenced by several components, such as sea-ice on the northern shelves and river discharge in the Gulf of St. Lawrence. The bottom salinity exhibits no clear seasonal cycle, but its spatial distribution is highly correlated with bathymetry, thus Slope Water and its intrusion on the shelf can be identified by its relatively high salinity compared to shallow, fresher shelf water. Two different regimes can be identified, especially on the shelf, separated by the Laurentian Channel: advection influences the phasing of the seasonal cycle of surface salinity and bottom temperature to the north, while in the southern region, river runoff and air-sea heat flux forcing are dominant, especially over the shallower bathymetry.

  20. Snow and Ice Climatology of the Western United States and Alaska from MODIS

    Science.gov (United States)

    Rittger, K. E.; Painter, T. H.; Mattmann, C. A.; Seidel, F. C.; Burgess, A.; Brodzik, M.

    2013-12-01

    The climate and hydroclimate of the Western US and Alaska are tightly coupled to their snow and ice cover. The Western US depends on mountain snowmelt for the majority of its water supply to agriculture, industrial and urban use, hydroelectric generation, and recreation, all driven by increasing population and demand. Alaskan snow and glacier cover modulate regional climate and, as with the Western US, dominate water supply and hydroelectric generation in much of the state. Projections of climate change in the Western US and Alaska suggest that the most pronounced impacts will include reductions of mountain snow and ice cover, earlier runoff, and a greater fraction of rain instead of snow. We establish a snow and ice climatology of the Western US and Alaska using physically based MODIS Snow Covered Area and Grain size model (MODSCAG) for fractional snow cover, the MODIS Dust Radiative Forcing in Snow model (MODDRFS) for radiative forcing by light absorbing impurities in snow, and the MODIS Permanent Ice model (MODICE) for annual minimum exposed snow. MODSCAG and MODDRFS use EOS MOD09GA historical reflectance data (2000-2012) to provide daily and 8-day composites and near real time products since the beginning of 2013, themselves ultimately composited to 8-day products. The compositing method considers sensor-viewing geometry, solar illumination, clouds, cloud shadows, aerosols and noisy detectors in order to select the best pixel for an 8-day period. The MODICE annual minimum exposed snow and ice product uses the daily time series of fractional snow and ice from MODSCAG to generate annual maps. With this project we have established an ongoing, national-scale, consistent and replicable approach to assessing current and projected climate impacts and climate-related risk in the context of other stressors. We analyze the products in the Northwest, Southwest, and Alaska/Arctic regions of the National Climate Assessment for the last decade, the nation's hottest on record

  1. A climatology of the diurnal variations of stratospheric and mesospheric ozone over Bern, Switzerland

    Directory of Open Access Journals (Sweden)

    S. Studer

    2013-08-01

    Full Text Available The ground-based radiometer GROMOS, stationed in Bern (47.95° N, 7.44° E, Switzerland, has a unique dataset: it obtains ozone profiles from November 1994 to present with a time resolution of 30 min and equal quality during night- and daytime. Here, we derive a monthly climatology of the daily ozone cycle from 17 yr of GROMOS observation. We present the diurnal ozone variation of the stratosphere and mesosphere. Characterizing the diurnal cycle of stratospheric ozone is important for correct trend estimates of the ozone layer derived from satellite observations. The diurnal ozone cycle from GROMOS is compared to two models: The Whole Atmosphere Community Climate Model (WACCM and the Hamburg Model of Neutral and Ionized Atmosphere (HAMMONIA. Aura Microwave Limb Sounder (Aura/MLS ozone data, from night- and daytime overpasses over Bern, have also been included in the comparison. Generally, observation and models show good qualitative agreement: in the lower mesosphere, daytime ozone is for both GROMOS and models around 25% less than nighttime ozone (reference is 22:30–01:30. In the stratosphere, ozone reaches its maximum in the afternoon showing values several percent larger than the midnight value. It is important that diurnal ozone variations of this order are taken into account when merging different data sets for the derivation of long-term ozone trends in the stratosphere. Further, GROMOS and models indicate a seasonal behavior of daily ozone variations in the stratosphere with a larger afternoon maximum during daytime in summer than in winter. At 0.35 hPa, observations from GROMOS and Aura/MLS show a seasonal pattern in diurnal ozone variations with larger relative amplitudes during daytime in winter (−25 ± 5% than in summer (−18 ± 4% (compared to mean values around midnight. For the first time, a time series of the diurnal variations in ozone is presented: 17 yr of GROMOS data show strong interannual variations in the diurnal ozone

  2. Modeling Drought Impact Occurrence Based on Climatological Drought Indices for Europe

    Science.gov (United States)

    Stagge, J. H.; Kohn, I.; Tallaksen, L. M.; Stahl, K.

    2014-12-01

    Meteorological drought indices are often assumed to accurately characterize the severity of a drought event; however, these indices do not necessarily reflect the likelihood or severity of a particular type of drought impact experienced on the ground. In previous research, this link between index and impact was often estimated based on thresholds found by experience, measured using composite indices with assumed weighting schemes, or defined based on very narrow impact measures, using either a narrow spatial extent or very specific impacts. This study expands on earlier work by demonstrating the feasibility of relating user-provided impact reports to the climatological drought indices SPI and SPEI by logistic regression. The user-provided drought impact reports are based on the European Drought Impact Inventory (EDII, www.geo.uio.no/edc/droughtdb/), a newly developed online database that allows both public report submission and querying the more than 4,000 reported impacts spanning 33 European countries. This new tool is used to quantify the link between meteorological drought indices and impacts focusing on four primary impact types, spanning agriculture, energy and industry, public water supply, and freshwater ecosystem across five European countries. Statistically significant climate indices are retained as predictors using step-wise regression and used to compare the most relevant drought indices and accumulation periods for different impact types and regions. Agricultural impacts are explained best by 2-12 month anomalies, with 2-3 month anomalies found in predominantly rain-fed agricultural regions, and anomalies greater than 3 months related to agricultural management practices. Energy and industry impacts, related to hydropower and energy cooling water in these countries, respond to longer accumulated precipitation anomalies (6-12 months). Public water supply and freshwater ecosystem impacts are explained by a more complex combination of short (1-3 month

  3. Climatological sensitivity analysis of crop yield to changes in temperature and precipitation using particle filter

    Science.gov (United States)

    Yokozawa, M.; Sakurai, G.; Iizumi, T.

    2010-12-01

    The climatological sensitivities of crop yields to changes in mean temperature and precipitation during a period of the growing season were statistically examined. The sensitivity is defined as the change of yield in response to the change of climatic condition in the growth period from sowing to harvesting. The objective crops are maize and soybean, which are being cultivated in United States, Brazil and China as the world major production countries. We collected the yield data of maize and soybean on county level of United States from USDA during a period of 1980-2006, on Município level of Brazil during a period of 1990-2006 and on Xiàn level of China during a period of 1980-2005. While the data on only four provinces in China are used (Heilongjiang, Henan, Liaoning, and Shandong), total production of the four provinces reaches about 40% (maize) and 51% (soybean) to the country total (USDA 1997). We used JRA-25 reanalysis climate data distributed from the Japanese Meteorological Agency during a period of 1980 through 2006 with a resolution of 1.125° in latitude and longitude. To coincide in resolution, the crop yield data were reallocated into the same grids as climate. To eliminate economical and technical effects on yield, we detrended the time series data of yield and climate. We applied a local regression model to conduct the detrend (cubic weighting and M estimator of Tukey's bi-weight function). The time series data on the deviation from the trend were examined with the changes in temperature and precipitation for each grid using the particle filter. The particle filter used here is based on self-organizing state-space model. As a result, in the northern hemisphere, positive sensitivity, i.e. increase in temperature shifts the crop yield positively, is generally found especially in higher latitude, while negative sensitivity is found in the lower latitude. The neutral sensitivity is found in the regions where the mean temperature during growing season

  4. Jet characterization in the upper troposphere/lower stratosphere (UTLS: applications to climatology and transport studies

    Directory of Open Access Journals (Sweden)

    G. L. Manney

    2011-06-01

    Full Text Available A method of classifying the upper tropospheric/lower stratospheric (UTLS jets has been developed that allows satellite and aircraft trace gas data and meteorological fields to be efficiently mapped in a jet coordinate view. A detailed characterization of multiple tropopauses accompanies the jet characterization. Jet climatologies show the well-known high altitude subtropical and lower altitude polar jets in the upper troposphere, as well as a pattern of concentric polar and subtropical jets in the Southern Hemisphere, and shifts of the primary jet to high latitudes associated with blocking ridges in Northern Hemisphere winter. The jet-coordinate view segregates air masses differently than the commonly-used equivalent latitude (EqL coordinate throughout the lowermost stratosphere and in the upper troposphere. Mapping O3 data from the Aura Microwave Limb Sounder (MLS satellite and the Winter Storms aircraft datasets in jet coordinates thus emphasizes different aspects of the circulation compared to an EqL-coordinate framework: the jet coordinate reorders the data geometrically, thus highlighting the strong PV, tropopause height and trace gas gradients across the subtropical jet, whereas EqL is a dynamical coordinate that may blur these spatial relationships but provides information on irreversible transport. The jet coordinate view identifies the concentration of stratospheric ozone well below the tropopause in the region poleward of and below the jet core, as well as other transport features associated with the upper tropospheric jets. Using the jet information in EqL coordinates allows us to study trace gas distributions in regions of weak versus strong jets, and demonstrates weaker transport barriers in regions with less jet influence. MLS and Atmospheric Chemistry Experiment-Fourier Transform Spectrometer trace gas fields for spring 2008 in jet coordinates show very strong, closely correlated, PV, tropopause height and trace gas

  5. SPARC Data Initiative: Comparison of water vapor climatologies from international satellite limb sounders

    Science.gov (United States)

    Hegglin, M. I.; Tegtmeier, S.; Anderson, J.; Froidevaux, L.; Fuller, R.; Funke, B.; Jones, A.; Lingenfelser, G.; Lumpe, J.; Pendlebury, D.; Remsberg, E.; Rozanov, A.; Toohey, M.; Urban, J.; Clarmann, T.; Walker, K. A.; Wang, R.; Weigel, K.

    2013-10-01

    Within the SPARC Data Initiative, the first comprehensive assessment of the quality of 13 water vapor products from 11 limb-viewing satellite instruments (LIMS, SAGE II, UARS-MLS, HALOE, POAM III, SMR, SAGE III, MIPAS, SCIAMACHY, ACE-FTS, and Aura-MLS) obtained within the time period 1978-2010 has been performed. Each instrument's water vapor profile measurements were compiled into monthly zonal mean time series on a common latitude-pressure grid. These time series serve as basis for the "climatological" validation approach used within the project. The evaluations include comparisons of monthly or annual zonal mean cross sections and seasonal cycles in the tropical and extratropical upper troposphere and lower stratosphere averaged over one or more years, comparisons of interannual variability, and a study of the time evolution of physical features in water vapor such as the tropical tape recorder and polar vortex dehydration. Our knowledge of the atmospheric mean state in water vapor is best in the lower and middle stratosphere of the tropics and midlatitudes, with a relative uncertainty of ±2-6% (as quantified by the standard deviation of the instruments' multiannual means). The uncertainty increases toward the polar regions (±10-15%), the mesosphere (±15%), and the upper troposphere/lower stratosphere below 100 hPa (±30-50%), where sampling issues add uncertainty due to large gradients and high natural variability in water vapor. The minimum found in multiannual (1998-2008) mean water vapor in the tropical lower stratosphere is 3.5 ppmv (±14%), with slightly larger uncertainties for monthly mean values. The frequently used HALOE water vapor data set shows consistently lower values than most other data sets throughout the atmosphere, with increasing deviations from the multi-instrument mean below 100 hPa in both the tropics and extratropics. The knowledge gained from these comparisons and regarding the quality of the individual data sets in different regions

  6. Jet characterization in the upper troposphere/lower stratosphere (UTLS): applications to climatology and transport studies

    Science.gov (United States)

    Manney, G. L.; Hegglin, M. I.; Daffer, W. H.; Santee, M. L.; Ray, E. A.; Pawson, S.; Schwartz, M. J.; Boone, C. D.; Froidevaux, L.; Livesey, N. J.; Read, W. G.; Walker, K. A.

    2011-06-01

    A method of classifying the upper tropospheric/lower stratospheric (UTLS) jets has been developed that allows satellite and aircraft trace gas data and meteorological fields to be efficiently mapped in a jet coordinate view. A detailed characterization of multiple tropopauses accompanies the jet characterization. Jet climatologies show the well-known high altitude subtropical and lower altitude polar jets in the upper troposphere, as well as a pattern of concentric polar and subtropical jets in the Southern Hemisphere, and shifts of the primary jet to high latitudes associated with blocking ridges in Northern Hemisphere winter. The jet-coordinate view segregates air masses differently than the commonly-used equivalent latitude (EqL) coordinate throughout the lowermost stratosphere and in the upper troposphere. Mapping O3 data from the Aura Microwave Limb Sounder (MLS) satellite and the Winter Storms aircraft datasets in jet coordinates thus emphasizes different aspects of the circulation compared to an EqL-coordinate framework: the jet coordinate reorders the data geometrically, thus highlighting the strong PV, tropopause height and trace gas gradients across the subtropical jet, whereas EqL is a dynamical coordinate that may blur these spatial relationships but provides information on irreversible transport. The jet coordinate view identifies the concentration of stratospheric ozone well below the tropopause in the region poleward of and below the jet core, as well as other transport features associated with the upper tropospheric jets. Using the jet information in EqL coordinates allows us to study trace gas distributions in regions of weak versus strong jets, and demonstrates weaker transport barriers in regions with less jet influence. MLS and Atmospheric Chemistry Experiment-Fourier Transform Spectrometer trace gas fields for spring 2008 in jet coordinates show very strong, closely correlated, PV, tropopause height and trace gas gradients across the jet, and

  7. Aerosol climatology: on the discrimination of aerosol types over four AERONET sites

    Directory of Open Access Journals (Sweden)

    D. G. Kaskaoutis

    2007-05-01

    Full Text Available Aerosols have a significant regional and global effect on climate, which is about equal in magnitude but opposite in sign to that of greenhouse gases. Nevertheless, the aerosol climatic effect changes strongly with space and time because of the large variability of aerosol physical and optical properties, which is due to the variety of their sources, which are natural, and anthropogenic, and their dependence on the prevailing meteorological and atmospheric conditions. Characterization of aerosol properties is of major importance for the assessment of their role for climate. In the present study, 3-year AErosol RObotic NETwork (AERONET data from ground-based sunphotometer measurements are used to establish climatologies of aerosol optical depth (AOD and Ångström exponent α in several key locations of the world, characteristic of different atmospheric environments. Using daily mean values of AOD at 500 nm (AOD500 and Ångström exponent at the pair of wavelengths 440 and 870 nm (α 440–870, a discrimination of the different aerosol types occurring in each location is achieved. For this discrimination, appropriate thresholds for AOD500 and α 440–870 are applied. The discrimination of aerosol types in each location is made on an annual and seasonal basis. It is shown that a single aerosol type in a given location can exist only under specific conditions (e.g. intense forest fires or dust outbreaks, while the presence of well-mixed aerosols is the accustomed situation. Background clean aerosol conditions (AOD500<0.06 are mostly found over remote oceanic surfaces occurring on average in ~56.7% of total cases, while this situation is quite rare over land (occurrence of 3.8–13.7%. Our analysis indicates that these percentages change significantly from season to season. The spectral dependence of AOD exhibits large differences between the examined locations, while it exhibits a strong

  8. Climatological and radiative properties of midlatitude cirrus clouds derived by automatic evaluation of lidar measurements

    Science.gov (United States)

    Kienast-Sjögren, Erika; Rolf, Christian; Seifert, Patric; Krieger, Ulrich K.; Luo, Bei P.; Krämer, Martina; Peter, Thomas

    2016-06-01

    Cirrus, i.e., high, thin clouds that are fully glaciated, play an important role in the Earth's radiation budget as they interact with both long- and shortwave radiation and affect the water vapor budget of the upper troposphere and stratosphere. Here, we present a climatology of midlatitude cirrus clouds measured with the same type of ground-based lidar at three midlatitude research stations: at the Swiss high alpine Jungfraujoch station (3580 m a.s.l.), in Zürich (Switzerland, 510 m a.s.l.), and in Jülich (Germany, 100 m a.s.l.). The analysis is based on 13 000 h of measurements from 2010 to 2014. To automatically evaluate this extensive data set, we have developed the Fast LIdar Cirrus Algorithm (FLICA), which combines a pixel-based cloud-detection scheme with the classic lidar evaluation techniques. We find mean cirrus optical depths of 0.12 on Jungfraujoch and of 0.14 and 0.17 in Zürich and Jülich, respectively. Above Jungfraujoch, subvisible cirrus clouds (τ clouds of that type were observed. Cirrus have been observed up to altitudes of 14.4 km a.s.l. above Jungfraujoch, whereas they have only been observed to about 1 km lower at the other stations. These features highlight the advantage of the high-altitude station Jungfraujoch, which is often in the free troposphere above the polluted boundary layer, thus enabling lidar measurements of thinner and higher clouds. In addition, the measurements suggest a change in cloud morphology at Jungfraujoch above ˜ 13 km, possibly because high particle number densities form in the observed cirrus clouds, when many ice crystals nucleate in the high supersaturations following rapid uplifts in lee waves above mountainous terrain. The retrieved optical properties are used as input for a radiative transfer model to estimate the net cloud radiative forcing, CRFNET, for the analyzed cirrus clouds. All cirrus detected here have a positive CRFNET. This confirms that these thin, high cirrus have a warming effect on the Earth

  9. Applying "Climate" system to teaching basic climatology and raising public awareness of climate change issues

    Science.gov (United States)

    Gordova, Yulia; Okladnikov, Igor; Titov, Alexander; Gordov, Evgeny

    2016-04-01

    While there is a strong demand for innovation in digital learning, available training programs in the environmental sciences have no time to adapt to rapid changes in the domain content. A joint group of scientists and university teachers develops and implements an educational environment for new learning experiences in basics of climatic science and its applications. This so-called virtual learning laboratory "Climate" contains educational materials and interactive training courses developed to provide undergraduate and graduate students with profound understanding of changes in regional climate and environment. The main feature of this Laboratory is that students perform their computational tasks on climate modeling and evaluation and assessment of climate change using the typical tools of the "Climate" information-computational system, which are usually used by real-life practitioners performing such kind of research. Students have an opportunity to perform computational laboratory works using information-computational tools of the system and improve skills of their usage simultaneously with mastering the subject. We did not create an artificial learning environment to pass the trainings. On the contrary, the main purpose of association of the educational block and computational information system was to familiarize students with the real existing technologies for monitoring and analysis of data on the state of the climate. Trainings are based on technologies and procedures which are typical for Earth system sciences. Educational courses are designed to permit students to conduct their own investigations of ongoing and future climate changes in a manner that is essentially identical to the techniques used by national and international climate research organizations. All trainings are supported by lectures, devoted to the basic aspects of modern climatology, including analysis of current climate change and its possible impacts ensuring effective links between

  10. Towards a climatology of tropical cyclone morphometric structures using a newly standardized passive microwave satellite dataset

    Science.gov (United States)

    Cossuth, J.; Hart, R. E.

    2013-12-01

    storm's rainband and eyewall organization. Ultimately, this project develops a consistent climatology of TC structures using a new database of research-quality historical TC satellite microwave observations. Not only can such data sets more accurately study TC structural evolution, but they may facilitate automated TC intensity estimates and provide methods to enhance current operational and research products, such as at the NRL TC webpage (http://www.nrlmry.navy.mil/TC.html). The process of developing the dataset and possible objective definitions of TC structures using passive microwave imagery will be described, with preliminary results suggesting new methods to identify TC structures that may interrogate and expand upon physical and dynamical theories. Structural metrics such as threshold analysis of the outlines of the TC shape as well as methods to diagnose the inner-core size, completion, and magnitude will be introduced.

  11. Analysis of high temperature extremes and climatological drought long-term tendencies in Latvia

    Science.gov (United States)

    Briede, A.; Lizuma, L.

    2010-09-01

    Drought is one of the major climatic hazard, which is can cause significant damage to the Latvia's agriculture, forestry, hydropower production, fire safety as well as ecology conditions. During warm season drought are usually related to extremely hot conditions which can additionally cause heat wave related mortality or human health problems. This study investigated long-term variability and trends in Latvia's drought and extremely hot conditions using meteorological data from 10 meteorological stations for the period 1925-2009 and from station Riga-University for the period 1850-2009. The set of long-term climatological indices characterized drought and extremely hot conditions (summer days, tropical nights, warm nights and day-times, warm spell days, number of constitutive dry days, standardized precipitation index and fire safety index) were used for this investigation. According to long-term data from the station Riga -University, the number of summer days was much higher in the 1850-60-ties. Many more summer days occurred in the 1930-ties and in the beginning of the 21st century. The tendency observed from the beginning of the 20th century is caused by warm summers, especially the summer of 2002 with 60 days of maximum air temperatures above 25 0C, the highest for the whole period of instrumental observations. Unusually warm nights that normally follow extremely hot days are one of the factors characteristic of hot waves that effect human health and general state. The marked increasing tendency has not been identified for extremely hot nights, yet from early 1990-ties, tropic nights have been registered more often than in the rest of the observation period. Over the whole observation period statistically significant increases in warm days, nights and day-times have been noted. The obtained results indicate that during the 20th century precipitation in warm period showed a decreasing tendency. On a country-wide scale, results indicate that more droughts

  12. Climatological and radiative properties of midlatitude cirrus clouds derived by automatic evaluation of lidar measurements

    Science.gov (United States)

    Kienast-Sjögren, Erika; Rolf, Christian; Seifert, Patric; Krieger, Ulrich K.; Luo, Bei P.; Krämer, Martina; Peter, Thomas

    2016-06-01

    Cirrus, i.e., high, thin clouds that are fully glaciated, play an important role in the Earth's radiation budget as they interact with both long- and shortwave radiation and affect the water vapor budget of the upper troposphere and stratosphere. Here, we present a climatology of midlatitude cirrus clouds measured with the same type of ground-based lidar at three midlatitude research stations: at the Swiss high alpine Jungfraujoch station (3580 m a.s.l.), in Zürich (Switzerland, 510 m a.s.l.), and in Jülich (Germany, 100 m a.s.l.). The analysis is based on 13 000 h of measurements from 2010 to 2014. To automatically evaluate this extensive data set, we have developed the Fast LIdar Cirrus Algorithm (FLICA), which combines a pixel-based cloud-detection scheme with the classic lidar evaluation techniques. We find mean cirrus optical depths of 0.12 on Jungfraujoch and of 0.14 and 0.17 in Zürich and Jülich, respectively. Above Jungfraujoch, subvisible cirrus clouds (τ change in cloud morphology at Jungfraujoch above ˜ 13 km, possibly because high particle number densities form in the observed cirrus clouds, when many ice crystals nucleate in the high supersaturations following rapid uplifts in lee waves above mountainous terrain. The retrieved optical properties are used as input for a radiative transfer model to estimate the net cloud radiative forcing, CRFNET, for the analyzed cirrus clouds. All cirrus detected here have a positive CRFNET. This confirms that these thin, high cirrus have a warming effect on the Earth's climate, whereas cooling clouds typically have cloud edges too low in altitude to satisfy the FLICA criterion of temperatures below -38 °C. We find CRFNET = 0.9 W m-2 for Jungfraujoch and 1.0 W m-2 (1.7 W m-2) for Zürich (Jülich). Further, we calculate that subvisible cirrus (τ < 0.03) contribute about 5 %, thin cirrus (0.03 < τ < 0.3) about 45 %, and opaque cirrus (0.3 < τ) about 50 % of the total cirrus radiative forcing.

  13. Lower-tropospheric humidity: climatology, trends and the relation to the ITCZ

    Directory of Open Access Journals (Sweden)

    Alexander Läderach

    2013-07-01

    Full Text Available The tropical region is an area of maximum humidity and serves as the major humidity source of the globe. Among other phenomena, it is governed by the so-called Inter-Tropical Convergence Zone (ITCZ which is commonly defined by converging low-level winds or enhanced precipitation. Given its importance as a humidity source, we investigate the humidity fields in the tropics in different reanalysis data sets, deduce the climatology and variability and assess the relationship to the ITCZ. Therefore, a new analysis method of the specific humidity distribution is introduced which allows detecting the location of the humidity maximum, the strength and the meridional extent. The results show that the humidity maximum in boreal summer is strongly shifted northward over the warm pool/Asia Monsoon area and the Gulf of Mexico. These shifts go along with a peak in the strength in both areas; however, the extent shrinks over the warm pool/Asia Monsoon area, whereas it is wider over the Gulf of Mexico. In winter, such connections between location, strength and extent are not found. Still, a peak in strength is again identified over the Gulf of Mexico in boreal winter. The variability of the three characteristics is dominated by inter-annual signals in both seasons. The results using ERA-interim data suggest a positive trend in the Gulf of Mexico/Atlantic region from 1979 to 2010, showing an increased northward shift in the recent years. Although the trend is only weakly confirmed by the results using MERRA reanalysis data, it is in phase with a trend in hurricane activity – a possible hint of the importance of the new method on hurricanes. Furthermore, the position of the maximum humidity coincides with one of the ITCZ in most areas. One exception is the western and central Pacific, where the area is dominated by the double ITCZ in boreal winter. Nevertheless, the new method enables us to gain more insight into the humidity distribution, its variability and

  14. North Alabama Total Lightning Climatology in Support of Lightning Safety Operations

    Science.gov (United States)

    Stano, G. T.; Schultz, C. J.; Koshak, W. J.

    2015-12-01

    The North Alabama Lightning Mapping Array (NALMA) was installed in 2001 to observe total lightning (cloud-to-ground and intra-cloud) and study its relationship to convective activity. NALMA has served as ground-truth for the Tropical Rainfall Measuring Mission Lightning Imager (TRMM-LIS) and will again for the GOES-R Geostationary Lightning Mapper (GLM). Also, NASA's Short-term Prediction Research and Transition Center (SPoRT) has transitioned these data to National Weather Service Weather Forecast Offices to evaluate the impact in operations since 2003. This study focuses on seasonal and diurnal observations from NALMA's 14 year history. This is initially intended to improve lightning safety at Marshall Space Flight Center, but has other potential applications. Improvements will be made by creating a dataset to investigate temporal, spatial, and seasonal patterns in total lightning over the Tennessee Valley, compare these observations to background environmental parameters and the TRMM-LIS climatology, and investigate applying these data to specific points of interest. Unique characteristics, such as flash extent density and length of flashes can be investigated, which are unavailable from other lightning networks like the National Lightning Detection Network (NLDN). The NALMA and NLDN data can be combined such that end users can use total lightning to gain lead time on the initial cloud-to-ground flash of a storm and identify if lightning is extending far from the storm's core. This spatial extent can be analyzed to determine how often intra-cloud activity may impinge on a region of interest and how often a cloud-to-ground strike may occur in the region. The seasonal and diurnal lightning maps can aid with planning of various experiments or tests that often require some knowledge about future weather patterns months in advance. The main goal is to develop a protocol to enhance lightning safety everywhere once the Geostationary Lightning Mapper (GLM) is on orbit

  15. Changes in the ecosystem structure of the Black Sea under predicted climatological and anthropogenic variations

    Science.gov (United States)

    Akoglu, Ekin; Salihoglu, Baris; Fach Salihoglu, Bettina; Libralato, Simone; Cannaby, Heather; Oguz, Temel; Solidoro, Cosimo

    2014-05-01

    A dynamic Ecopath with Ecosim higher-trophic-level (HTL) model representation of the Black Sea ecosystem was coupled to the physical (BIMS-CIR) and biogeochemical (BIMS-ECO) models of the Black Sea in order to investigate historical anthropogenic and climatological interactions and feedbacks in the ecosystem. Further, the coupled models were used to assess the likely consequences of these interactions on the ecosystem's structure and functioning under predicted future climate (IPCC A1B) and fishing variability. Therefore, two model scenarios were used; i) a hindcast scenario (1980-1999) to evaluate and understand the impacts of the short-term climate and physical variability and the introduction of invasive species on the Black Sea ecosystem, and ii) a forecast scenario (2080-2099) to investigate the potential implications of climate change and anthropogenic exploitation on living resources of the Black Sea ecosystem by the end of the 21st century. According to the outcomes of the hindcast simulation, fisheries were found to be the main driver in determining the structure and functioning of the Black Sea ecosystem under changing environmental conditions. The coupled physical-biogeochemical forecast simulations predicted a slight but statistically significant basin-wide increase in the Black Sea's primary productivity by the end of the century due to increased stratification induced by basin-wide temperature increase and reduced Cold Intermediate Layer (CIL) formation which increased the residence time of riverine nutrients within the euphotic zone. Despite this increased primary productivity, the HTL model forecast simulation predicted a significant decrease in the commercial fish stocks primarily due to fisheries exploitation if current catch rates are maintained into the future. Results further suggested that some economically important small pelagic fish species are likely to disappear from the ecosystem making the recovery of the already-collapsed piscivorous

  16. A Study of Precipitation Climatology and Its Variability over Europe Using an Advanced Regional Model (WRF)

    KAUST Repository

    Dasari, Hari Prasad

    2015-03-06

    zones are found. Overall, the simulated rainfall climatology was reproduced well for the low and heavy rainfall followed by very heavy and extremely heavy rainfall in Europe and the simulation is better in the Iberian west coast, central northern Europe and Alps Mountains.

  17. Oceanic Climatology in the Coupled Model FGOALS-g2:Improvements and Biases

    Institute of Scientific and Technical Information of China (English)

    LIN Pengfei; YU Yongqiang; LIU Hailong

    2013-01-01

    The present study examines simulated oceanic climatology in the Flexible Global Ocean-Atmosphere-Land System model,Grid-point Version 2 (FGOALS-g2) forced by historical external forcing data.The oceanic temperatures and circulations in FGOALS-g2 were found to be comparable to those observed,and substantially improved compared to those simulated by the previous version,FGOALS-g1.0.Compared with simulations by FGOALS-g1.0,the shallow mixed layer depths were better captured in the eastern Atlantic and Pacific Ocean in FGOALS-g2.In the high latitudes of the Northern Hemisphere,the cold biases of SST were about 1℃ 5℃ smaller in FGOALS-g2.The associated sea ice distributions and their seasonal cycles were more realistic in FGOALS-g2.The pattern of Atlantic Meridional Overturning Circulation (AMOC) was better simulated in FGOALS-g2,although its magnitude was larger than that found in observed data.The simulated Antarctic Circumpolar Current (ACC) transport was about 140 Sv through the Drake Passage,which is close to that observed.Moreover,Antarctic Intermediate Water (AAIW) was better captured in FGOALS-g2.However,large SST cold biases (>3℃) were still found to exist around major western boundary currents and in the Barents Sea,which can be explained by excessively strong oceanic cold advection and unresolved processes owing to the coarse resolution.In the Indo-Pacific warm pool,the cold biases were partly related to the excessive loss of heat from the ocean.Along the eastern coast in the Atlantic and Pacific Oceans,the warm biases were due to overestimation of shortwave radiation.In the Indian Ocean and Southern Ocean,the surface fresh biases were mainly due to the biases of precipitation.In the tropical Pacific Ocean,the surface fresh biases (>2 psu) were mainly caused by excessive precipitation and oceanic advection.In theIndo-Pacific Ocean,fresh biases were also found to dominate in the upper 1000 m,except in the northeastern Indian Ocean.There were warm and

  18. Climatology of new particle formation events in the subtropical North Atlantic free troposphere at Izaña GAW observatory

    OpenAIRE

    M. I. García; S. Rodríguez; González, Y.; R. D. García

    2013-01-01

    A climatology of new particle formation (NPF) events in the subtropical North Atlantic free troposphere is presented. A four year data set (June 2008–June 2012), which includes number size distributions (10–600 nm), reactive gases (SO2, NOx, and O3), several components of solar radiation and meteorological parameters, measured at Izaña Global Atmospheric Watch observatory (2400 m above sea level; Tenerife, Canary Islands) was analysed. On average, NPF occurred during 30% of the days,the mean ...

  19. The SPARC Data Initiative: comparisons of CFC-11, CFC-12, HF and SF6 climatologies from international satellite limb sounders

    OpenAIRE

    S. Tegtmeier; Hegglin, M. I.; Anderson, J; Funke, B.; Gille, J.; Jones, A; Smith, L; von Clarmann, T.; K. A. Walker

    2016-01-01

    A quality assessment of the CFC-11 (CCl3F), CFC-12 (CCl2F2), HF, and SF6 products from limb-viewing satellite instruments is provided by means of a detailed intercomparison. The climatologies in the form of monthly zonal mean time series are obtained from HALOE, MIPAS, ACE-FTS, and HIRDLS within the time period 1991–2010. The intercomparisons focus on the mean biases of the monthly and annual zonal mean fields and aim to identify their vertical, latitudinal and temporal stru...

  20. The vertical cloud structure of the West African monsoon: a 4 year climatology using CloudSat and CALIPSO

    OpenAIRE

    Stein, Thorwald H. M.; D. J. Parker; J. Delanoë; Dixon, N. S.; Hogan, Robin J.; Knippertz, P; Maidment, Ross I.; J. H. Marsham

    2011-01-01

    The West African summer monsoon (WAM) is an important driver of the global climate and locally provides most of the annual rainfall. A solid climatological knowledge of the complex vertical cloud structure is invaluable to forecasters and modelers to improve the understanding of the WAM. In this paper, 4 years of data from the CloudSat profiling radar and CALIPSO are used to create a composite zonal mean vertical cloud and precipitation structure for the WAM. For the first time, the near-coin...

  1. Climatología de la precipitación de tres días en la Cuenca del Plata Climatology of three days precipitation in La Plata Basin

    Directory of Open Access Journals (Sweden)

    Gustavo Naumann

    2012-06-01

    Full Text Available Una climatología de distintas propiedades de la precipitación en intervalos de tres días es desarrollada en el presente trabajo, la cual es de especial importancia para el pronóstico extendido de precipitación. Por lo tanto el objetivo fundamental de esta climatología es el desarrollo y el inicio de pronósticos extendidos de 6 a 10 días en términos de probabilidades divididas en categorías. Para esto, se analizan las frecuencias de días con precipitación en ventanas de 3 días. Cada frecuencia de cero días de precipitación para el día i es el resultado de la ausencia de precipitación en ventanas móviles de tres días centradas en el día i, de la misma forma se obtienen las frecuencias hasta tres días con precipitación respectivamente. Se emplean los datos de 94 estaciones en un período común (1959-1998 en el área de estudio. Se estudian las ondas anuales de las propiedades obtenidas para las precipitaciones y su síntesis a través de la descomposición en armónicos. Se propone una representación vectorial de las propiedades que definen el análisis armónico, tales como la fecha de ocurrencia del máximo (su fase y su amplitud. Finalmente, se pone especial énfasis en el estudio de las condiciones extremas de eventos de precipitación, como por ejemplo, la marcha anual de los máximos representados por el percentil 90 de precipitación diaria.A climatology of various properties of precipitation in intervals of three days is developed. This climatology has a particular importance for the extended forecast of precipitation. Therefore the main objective of this climatology is the development and the initiation of extended forecasts of 6 to 10 days in terms of probabilities divided into categories. For this, the frequencies of days with precipitation in three days windows are analyzed. Each frequency of zero days of precipitation for day i is the result of a lack of rainfall in three days moving windows centered on i, in

  2. Metrological challenges for measurements of key climatological observables: oceanic salinity and pH, and atmospheric humidity. Part 1: overview

    Science.gov (United States)

    Feistel, R.; Wielgosz, R.; Bell, S. A.; Camões, M. F.; Cooper, J. R.; Dexter, P.; Dickson, A. G.; Fisicaro, P.; Harvey, A. H.; Heinonen, M.; Hellmuth, O.; Kretzschmar, H.-J.; Lovell-Smith, J. W.; McDougall, T. J.; Pawlowicz, R.; Ridout, P.; Seitz, S.; Spitzer, P.; Stoica, D.; Wolf, H.

    2016-02-01

    Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest ‘greenhouse’ gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organizations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology.

  3. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL during NH winter

    Directory of Open Access Journals (Sweden)

    K. Krüger

    2008-02-01

    Full Text Available A long-term climatology of air mass transport through the tropical tropopause layer (TTL is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the upper part of the TTL, the averaged diabatic ascent is 0.5 K/day during Northern Hemisphere (NH winters 1992–2001. Climatological maps show a cooling and strengthening of this part of the residual circulation during the 1990s and early 2000s compared to the long-term mean. Lagrangian cold point (LCP fields show systematic differences for varying time periods and natural forcing components. The interannual variability of LCP temperature and density fields is found to be influenced by volcanic eruptions, El Niño Southern Oscillation (ENSO, Quasi-Biennial Oscillation (QBO and the solar cycle. The coldest and driest TTL is reached during QBO easterly phase and La Niña over the western Pacific, whereas during volcanic eruptions, El Niño and QBO westerly phase it is warmer and less dry.

  4. Long-term climatology of air mass transport through the Tropical Tropopause Layer (TTL during NH winter

    Directory of Open Access Journals (Sweden)

    K. Krüger

    2007-09-01

    Full Text Available A long-term climatology of air mass transport through the tropical tropopause layer (TTL is presented, covering the period from 1962–2005. The transport through the TTL is calculated with a Lagrangian approach using radiative heating rates as vertical velocities in an isentropic trajectory model. We demonstrate the improved performance of such an approach compared to previous studies using vertical winds from meteorological analyses. Within the TTL, the averaged diabatic ascent is 0.5 K/day during Northern Hemisphere (NH winters 1992–2001, close to observations from the tape recorder. Climatological maps show a cooling and strengthening of this part of the residual circulation during the late 1990s and early 2000s compared to the long-term mean. Lagrangian cold point (LCP fields show systematic differences for varying time periods and natural forcing components. The interannual variability of LCP temperature and density fields are found to be influenced by volcanic eruptions, ENSO, QBO and the solar cycle. The coldest and driest TTL is reached during QBOE and La Niña over the western Pacific, whereas during volcanic eruptions, El Niño and QBOW it is warmer and less dry.

  5. Action spectra affect variability of the climatology of biologically effective ultraviolet radiation on cloud-free days

    International Nuclear Information System (INIS)

    Action spectrum (AS) describes the relative effectiveness of ultraviolet (UV) radiation in producing biological effects and allows spectral UV irradiance to be weighted in order to compute biologically effective UV radiation (UVBE). The aim of this research was to study the seasonal and latitudinal distribution over Europe of daily UVBE doses responsible for various biological effects on humans and plants. Clear sky UV radiation spectra were computed at 30-min time intervals for the first day of each month of the year for Rome, Potsdam and Trondheim using a radiative transfer model fed with climatological data. Spectral data were weighted using AS for erythema, vitamin D synthesis, cataract and photo-keratitis for humans, while the generalised plant damage and the plant damage AS were used for plants. The daily UVBE doses for the above-mentioned biological processes were computed and are analysed in this study. The patterns of variation due to season (for each location) and latitude (for each date) resulted as being specific for each adopted AS. The biological implications of these results are briefly discussed highlighting the importance of a specific UVBE climatology for each biological process. (authors)

  6. Nitric acid in the stratosphere based on Odin observations from 2001 to 2007 – Part 1: A global climatology

    Directory of Open Access Journals (Sweden)

    M. L. Santee

    2008-05-01

    Full Text Available The Sub-Millimetre Radiometer (SMR on board the Odin satellite, launched in February 2001, observes thermal emissions of stratospheric nitric acid (HNO3 originating from the Earth limb in a band centred at 544.6 GHz. Height-resolved measurements of the global distribution of nitric acid in the stratosphere between ~18–45 km (~1.5–60 hPa were performed approximately on two observation days per week. An HNO3 climatology based on roughly 6 years of observations from August 2001 to December 2007 was created. The study highlights the spatial and seasonal variation of nitric acid in the stratosphere, characterised by a pronounced seasonal cycle at middle and high latitudes with maxima during late fall and minima during spring, strong denitrification in the lower stratosphere of the Antarctic polar vortex during winter (the irreversible removal of NOy by the sedimentation of cloud particles containing HNO3, as well as high quantities of HNO3 formed every winter at high-latitudes in the middle and upper stratosphere. A strong inter-annual variability is observed in particular at high latitudes. A comparison with a stratospheric HNO3 climatology based on UARS/MLS measurements from the 1990s shows a good consistency and agreement of the main morphological features in the potential temperature range ~465 to ~960 K, if the different characteristics of the data sets such as altitude range and resolution are considered.

  7. The SPARC Data Initiative: Comparison of upper troposphere/lower stratosphere ozone climatologies from limb-viewing instruments and the nadir-viewing Tropospheric Emission Spectrometer

    Science.gov (United States)

    Neu, J. L.; Hegglin, M. I.; Tegtmeier, S.; Bourassa, A.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A.; Rozanov, A.; Toohey, M.; Clarmann, T.; Walker, K. A.; Worden, J. R.

    2014-06-01

    We present the first comprehensive intercomparison of currently available satellite ozone climatologies in the upper troposphere/lower stratosphere (UTLS) (300-70 hPa) as part of the Stratosphere-troposphere Processes and their Role in Climate (SPARC) Data Initiative. The Tropospheric Emission Spectrometer (TES) instrument is the only nadir-viewing instrument in this initiative, as well as the only instrument with a focus on tropospheric composition. We apply the TES observational operator to ozone climatologies from the more highly vertically resolved limb-viewing instruments. This minimizes the impact of differences in vertical resolution among the instruments and allows identification of systematic differences in the large-scale structure and variability of UTLS ozone. We find that the climatologies from most of the limb-viewing instruments show positive differences (ranging from 5 to 75%) with respect to TES in the tropical UTLS, and comparison to a "zonal mean" ozonesonde climatology indicates that these differences likely represent a positive bias for p ≤ 100 hPa. In the extratropics, there is good agreement among the climatologies regarding the timing and magnitude of the ozone seasonal cycle (differences in the peak-to-peak amplitude of <15%) when the TES observational operator is applied, as well as very consistent midlatitude interannual variability. The discrepancies in ozone temporal variability are larger in the tropics, with differences between the data sets of up to 55% in the seasonal cycle amplitude. However, the differences among the climatologies are everywhere much smaller than the range produced by current chemistry-climate models, indicating that the multiple-instrument ensemble is useful for quantitatively evaluating these models.

  8. Isotope climatology of Canada: Insights from the first five years of CNIP operation

    International Nuclear Information System (INIS)

    The isotopic composition of precipitation is an integrated climate field reflecting temperature, amount of precipitation, air-mass source and history. Previous analysis of Canadian data within the GNIP database has shown that the distribution of long-term weighted isotope fields across Canada clearly reflect differences in the dominant meteorological regimes associated with each region. While these studies were fundamental in providing local hydrological input functions and calibration for paleoclimate archives, there was growing awareness of the significant value of monthly snapshots of the precipitation isotope fields as benchmark maps of the ongoing and dynamic evolution of the global water cycle. Snapshots of the isotope climatology of Canada were limited by the spatial and temporal patchiness of the existing Canadian data. The Canadian Network for Isotopes in Precipitation (CNIP) was initiated as a joint venture between university and government researchers to provide the spatial and temporal data necessary to examine the sensitivity of isotope fields to changes in circulation patterns, particularly in northern areas where the signal to noise ratio is much lower. The network consists of 18 stations distributed across Canada (spanning almost 40 deg. of latitude and 70 deg. of longitude) collecting weighted monthly precipitation samples. This marks the first time that both the southern and northern regions of the country have been simultaneously sampled. Sampling of the southern stations was initiated in 1997 to supplement an existing informal arctic network (now formally incorporated in CNIP) resulting in a 5 year dataset for the entire country, including a complete El Nino/Southern Oscillation (ENSO) cycle. The arctic subset of the data includes over a decade of sampling and consequently can be used to evaluate the isotopic expression of the Arctic Oscillation (AO). The data have been reconfigured as an isotope overlay compatible with pressure and flux field

  9. Climatology and dynamics of nocturnal low-level stratus over the southern West African monsoon region

    Science.gov (United States)

    Fink, A. H.; Schuster, R.; Knippertz, P.; van der Linden, R.

    2013-12-01

    The southern parts of West Africa, from the coast to about 10°N, are frequently covered by an extensive deck of shallow, low (200 - 400 m above ground) stratus or stratocumulus clouds during the summer monsoon season. These clouds usually form at night in association with a nocturnal low-level jet (NLLJ) and can persist into the early afternoon hours until they are dissipated or replaced by fair-weather cumuli. Recent work suggests that the stratus deck and its effect on the surface radiation balance are unsatisfactorily represented in standard satellite retrievals and simulations by state-of-the-art climate models. We will present the first ever climatology of the diurnal cycle of the low cloud deck based on surface observations and satellite products. In addition, we use high-resolution regional simulations with the Weather Research and Forecast (WRF) model and observations from the African Monsoon Multidisciplinary Analysis (AMMA) 2006 campaign to investigate (a) the spatiotemporal distribution, (b) the influence on the radiation balance, and (c) the detailed formation and maintenance mechanisms of the stratiform clouds as simulated by the model. The model configuration used for this study has been determined following an extensive sensitivity study, which has shown that at least some configurations of WRF satisfactorily reproduce the diurnal cycle of the low cloud evolution. The main conclusions are: (a) The observed stratus deck forms after sunset along the coast, spreads inland in the course of the night, reaches maximum poleward extent at about 10°N around 09-10 local time and dissipates in the early afternoon. (b) The average surface net radiation balance in stratus-dominated regions is 35 W m-2 lower than in those with less clouds. (c) The cloud formation is related to a subtle balance between 'stratogenic' upward (downward) fluxes of latent (sensible) heat caused by shear-driven turbulence below the NLLJ, cold advection from the ocean, forced lifting at

  10. A climatological study of sea breeze clouds in the southeast of the Iberian Peninsula (Alicante, Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Azorin-Molina, C. [Grupo de Climatologia, Universidad de Barcelona, Barcelona, Cataluna (Spain)]. E-mail: cazorin@ceam.es; Sanchez-Lorenzo, A. [Grupo de Climatologia, Universidad de Barcelona, Barcelona, Cataluna (Spain); Calbo, J. [Grupo de Fisica Ambiental, Universidad de Girona, Campus Montilivi, Cataluna (Spain)

    2009-01-15

    Sea breezes blow under anticyclonic weather types, weak surface pressure gradients, intense solar radiation and relatively cloud-free skies. Generally, total cloud cover must be less than 4/8 in order to cause a thermal and pressure difference between land and sea air which allows the development of this local wind circulation. However, many numerical and observational studies have analyzed the ability of sea breezes to generate clouds in the convective internal boundary layer and in the sea breeze convergence zone. Accordingly, the aim of this study is to statistically analyze the impact of sea breezes on cloud types in the convective internal boundary layer and in the sea breeze convergence zone. The study area is located in the southeast of the Iberian Peninsula (province of Alicante, Spain) and the survey corresponds to a 6-yr study period (2000-2005). This climatological study is mainly based on surface cloud observations at the Alicante-Ciudad Jardin station (central coastal plain) and on an extensive cloud observation field campaign at the Villena-Ciudad station (Prebetic mountain ranges) over a 3-yr study period (2003-2005). The results confirm the hypothesis that the effect of sea breezes on cloud genera is to increase the frequency of low (Stratus) and convective (Cumulus) clouds. Sea breezes trigger the formation of thunderstorm clouds (Cumulonimbus) at the sea breeze convergence zone, which also have a secondary impact on high-level (Cirrus, Cirrocumulus, Cirrostratus), medium-level (Altostratus, Altocumulus) and low-level clouds (Stratus, Stratocumulus, Nimbostratus) associated with the Cumulonimbus clouds (e.g., Cumulonimbus anvil). [Spanish] Las brisas marinas soplan bajo tipos de tiempo anticiclonicos, debiles gradientes de presion atmosferica, radiacion solar intensa y cielos practicamente despejados. Por lo general, la cobertura nubosa total debe ser inferior a 4/8 para que se genere un diferencial termico y de presion entre el aire sobre las

  11. Revisiting Melton: Analyzing the correlation structure of geomorphological and climatological parameters

    Science.gov (United States)

    Carothers, R. A.; Sangireddy, H.; Passalacqua, P.

    2013-12-01

    In his expansive 1957 study of over 80 basins in Arizona, Colorado, New Mexico, and Utah, Mark Melton measured key morphometric, soil, land cover, and climatic parameters [Melton, 1957]. He identified correlations between morphological parameters and climatic regimes in an attempt to characterize the geomorphology of the basin as a function of climate and vegetation. Using modern techniques such as high resolution digital terrain models in combination with high spatial resolution weather station records, vector soil maps, seamless raster geological data, and land cover vector maps, we revisit Melton's 1957 dataset with the following hypotheses: (1) Patterns of channelization carry strong, codependent signatures in the form of statistical correlations of rainfall variability, soil type, and vegetation patterns. (2) Channelization patterns reflect the erosion processes on sub-catchment scale and the subsequent processes of vegetation recovery and gullying. In order to characterize various topographic and climatic parameters, we obtain elevation and land cover data from the USGS National Elevation dataset, climate data from the Western Regional Climate Center and PRISM climate group database, and soil type from the USDA STATSGO soil database. We generate a correlative high resolution database on vegetation, soil cover, lithology, and climatology for the basins identified by Melton in his 1957 study. Using the GeoNet framework developed by Passalacqua et al. [2010], we extract various morphological parameters such as slope, drainage density, and stream frequency. We also calculate metrics for patterns of channelization such as number of channelized pixels in a basin and channel head density. In order to understand the correlation structure between climate and morphological variables, we compute the Pearson's correlation coefficient similar to Melton's analysis and also explore other statistical procedures to characterize the feedbacks between these variables. By

  12. Effects of time-series length and gauge network density on rainfall climatology estimates in Latin America

    Science.gov (United States)

    Maeda, E.; Arevalo, J.; Carmona-Moreno, C.

    2012-04-01

    Despite recent advances in the development of satellite sensors for monitoring precipitation at high spatial and temporal resolutions, the assessment of rainfall climatology still relies strongly on ground-station measurements. The Global Historical Climatology Network (GHCN) is one of the most popular stations database available for the international community. Nevertheless, the spatial distribution of these stations is not always homogeneous and the record length largely varies for each station. This study aimed to evaluate how the number of years recorded in the GHCN stations and the density of the network affect the uncertainties of annual rainfall climatology estimates in Latin America. The method applied was divided in two phases. In the first phase, Monte Carlo simulations were performed to evaluate how the number of samples and the characteristics of rainfall regime affect estimates of annual average rainfall. The simulations were performed using gamma distributions with pre-defined parameters, which generated synthetic annual precipitation records. The average and dispersion of the synthetic records were then estimated through the L-moments approach and compared with the original probability distribution that was used to produce the samples. The number of records (n) used in the simulation varied from 10 to 150, reproducing the range of number of years typically found in meteorological stations. A power function, in the form RMSE= f(n) = c.na, where the coefficients were defined as a function of the rainfall statistical dispersion, was applied to fit the errors. In the second phase of the assessment, the results of the simulations were extrapolated to real records obtained by the GHCN over Latin America, creating estimates of errors associated with number of records and rainfall characteristics in each station. To generate a spatially-explicit representation of the uncertainties, the errors in each station were interpolated using the inverse distance

  13. A regional rainfall climatology over Mexico and the southwest United States derived from passive microwave and geosynchronous infrared data

    Science.gov (United States)

    Negri, Andrew J.; Adler, Robert F.; Maddox, Robert A.; Howard, Kenneth W.; Keehn, Peter R.

    1993-01-01

    A three-year climatology of satellite-estimated rainfall for the warm season for the southwest United States and Mexico has been derived from data from the Special Sensor Microwave Imager (SSM/I). The microwave data have been stratified by month (June, July, August), year (1988, 1989, 1990), and time of day (morning and evening orbits). A rain algorithm was employed that relates 86-GHz brightness temperatures to rain rate using a coupled cloud-radiative transfer model. Results identify an early evening maximum in rainfall along the western slope of the Sierra Madre Occidental during all three months. A prominent morning rainfall maximum was found off the western Mexican coast near Mazatlan in July and August. Substantial differences between morning and evening estimates were noted. To the extent that three years constitute a climatology, results of interannual variability are presented. Results are compared and contrasted to high-resolution (8 km, hourly) infrared cloud climatologies, which consist of the frequency of occurrence of cloud colder than -38 C and -58 C. This comparison has broad implications for the estimation of rainfall by simple (cloud threshold) techniques. By sampling the infrared data to approximate the time and space resolution of the microwave, we produce ratios (or adjustment factors) by which we can adjust the infrared rain estimation schemes. This produces a combined microwave/infrared rain algorithm for monthly rainfall. Using a limited set of raingage data as ground truth, an improvement (lower bias and root-mean-square error) was demonstrated by this combined technique when compared to either method alone. The diurnal variability of convection during July 1990 was examined using hourly rain estimates from the Geostationary Operational Environmental Satellite (GOES) precipitation index and the convective stratiform technique, revealing a maximum in estimated rainfall from 1800 to 2100 local time. It is in this time period when the SSM

  14. The SPARC Data Initiative: comparisons of CFC-11, CFC-12, HF and SF6 climatologies from international satellite limb sounders

    Science.gov (United States)

    Tegtmeier, S.; Hegglin, M. I.; Anderson, J.; Funke, B.; Gille, J.; Jones, A.; Smith, L.; von Clarmann, T.; Walker, K. A.

    2016-02-01

    A quality assessment of the CFC-11 (CCl3F), CFC-12 (CCl2F2), HF, and SF6 products from limb-viewing satellite instruments is provided by means of a detailed intercomparison. The climatologies in the form of monthly zonal mean time series are obtained from HALOE, MIPAS, ACE-FTS, and HIRDLS within the time period 1991-2010. The intercomparisons focus on the mean biases of the monthly and annual zonal mean fields and aim to identify their vertical, latitudinal and temporal structure. The CFC evaluations (based on MIPAS, ACE-FTS and HIRDLS) reveal that the uncertainty in our knowledge of the atmospheric CFC-11 and CFC-12 mean state, as given by satellite data sets, is smallest in the tropics and mid-latitudes at altitudes below 50 and 20 hPa, respectively, with a 1σ multi-instrument spread of up to ±5 %. For HF, the situation is reversed. The two available data sets (HALOE and ACE-FTS) agree well above 100 hPa, with a spread in this region of ±5 to ±10 %, while at altitudes below 100 hPa the HF annual mean state is less well known, with a spread ±30 % and larger. The atmospheric SF6 annual mean states derived from two satellite data sets (MIPAS and ACE-FTS) show only very small differences with a spread of less than ±5 % and often below ±2.5 %. While the overall agreement among the climatological data sets is very good for large parts of the upper troposphere and lower stratosphere (CFCs, SF6) or middle stratosphere (HF), individual discrepancies have been identified. Pronounced deviations between the instrument climatologies exist for particular atmospheric regions which differ from gas to gas. Notable features are differently shaped isopleths in the subtropics, deviations in the vertical gradients in the lower stratosphere and in the meridional gradients in the upper troposphere, and inconsistencies in the seasonal cycle. Additionally, long-term drifts between the instruments have been identified for the CFC-11 and CFC-12 time series. The evaluations as a

  15. Climatología urbana por modificación antropogénica. Alteración del balance de energía natural / Urban climatology by anthropogenic modification. Alteration of the natural energy balance

    Directory of Open Access Journals (Sweden)

    Fuentes Pérez, Carlos Alberto

    2015-09-01

    Full Text Available La investigación valora el análisis climático histórico para establecer la temperatura y humedad relativa media, en contraste con la climatología urbana por modificación antropogénica estudio de caso, y su contribución de consigna fijado para invierno y verano que son las estaciones críticas. El procedimiento metodológico a implementar, apoya a los planificadores urbanos a no tener que participar científicamente para evaluar el emplazamiento térmico de sus proyectos y por lo tanto se puede acelerar el proceso de diseño sin comprometer el énfasis en el contexto urbano sustentable. Con base a los resultados se establecen las islas de calor urbano y su huella térmica en el hábitat. El objetivo de la presente investigación es determinar la climatología urbana por modificación antropogénica y su alteración a la calidad del hábitat en Tampico, México. The research assesses the historical climate analysis to determine the average temperature and relative humidity, in contrast to urban anthropogenic weather modification case study, and their contribution setpoint set for winter and summer are the season’s criticism. The methodology to implement, procedure supports urban planners will not have to participate to scientifically evaluate the thermal construction projects and therefore can accelerate the design process without compromising the emphasis on sustainable urban context. Based on the results of urban heat islands and thermal footprint habitat established. The objective of this research is to determine the urban climate by anthropogenic modification and alteration of habitat quality in Tampico, Mexico.

  16. Teaching the Teachers on Building Climatology. (CIB Steering Group S 4, Colloquium, Stockholm, September 4-6, 1972). CIB Proceedings No. 25.

    Science.gov (United States)

    National Swedish Inst. for Building Research, Stockholm.

    This publication comprises a collection of papers and synopses of discussions dating from the "Teaching the Teachers in Building Climatology" colloquium which was held under the auspices of the International Council for Building Research (CIB) and the World Meteorological Organization (WMO). The papers deal with the use of various meteorological…

  17. Toward a Combined SAGE II-HALOE Aerosol Climatology: An Evaluation of HALOE Version 19 Stratospheric Aerosol Extinction Coefficient Observations

    Science.gov (United States)

    Thomason, L. W.

    2012-01-01

    Herein, the Halogen Occultation Experiment (HALOE) aerosol extinction coefficient data is evaluated in the low aerosol loading period after 1996 as the first necessary step in a process that will eventually allow the production of a combined HALOE/SAGE II (Stratospheric Aerosol and Gas Experiment) aerosol climatology of derived aerosol products including surface area density. Based on these analyses, it is demonstrated that HALOE's 3.46 microns is of good quality above 19 km and suitable for scientific applications above that altitude. However, it is increasingly suspect at lower altitudes and should not be used below 17 km under any circumstances after 1996. The 3.40 microns is biased by about 10% throughout the lower stratosphere due to the failure to clear NO2 but otherwise appears to be a high quality product down to 15 km. The 2.45 and 5.26 micron aerosol extinction coefficient measurements are clearly biased and should not be used for scientific applications after the most intense parts of the Pinatubo period. Many of the issues in the aerosol data appear to be related to either the failure to clear some interfering gas species or doing so poorly. For instance, it is clear that the 3.40micronaerosol extinction coefficient measurements can be improved through the inclusion of an NO2 correction and could, in fact, end up as the highest quality overall HALOE aerosol extinction coefficient measurement. It also appears that the 2.45 and 5.26 micron channels may be improved by updating the Upper Atmosphere Pilot Database which is used as a resource for the removal of gas species otherwise not available from direct HALOE measurements. Finally, a simple model to demonstrate the promise of mixed visible/infrared aerosol extinction coefficient ensembles for the retrieval of bulk aerosol properties demonstrates that a combined HALOE/SAGE II aerosol climatology is feasible and may represent a substantial improvement over independently derived data sets.

  18. NO2 measurements during the MANTRA 2002 balloon campaign: comparisons with satellite measurements, climatology, and the Canadian Middle Atmosphere Model.

    Science.gov (United States)

    Melo, S.; Mantra-Osiris-Sciamachy

    This work reports on the results from the Middle Atmospheric Nitrogen TRend Assessment (MANTRA) balloon campaign conducted at Vanscoy, Saskatchewan, Canada (52°N, 107°W) on September 3 2002. Vertical distributions of ozone and NO2 were measured from the balloon by 3 UV-visible grating spectrometers (SPS, MAESTRO-B, and SAOZ), all in solar occultation mode. Ozone profiles were obtained from ozonesondes launched daily through the campaigns. Another UV-visible spectrometer was operated on the ground measuring scattered sunlight in a zenith-sky configuration. Ozone and NO2 slant column densities were extracted from those measurements as a function of solar zenith angles, and NO2 vertical profiles were retrieved from the NO2 slant column values. Here we compare NO2 profiles measured during the MANTRA campaign with a climatology based on observations from satellites, other balloons, and a set of NDSC sites, as well as with the Canadian Middle Atmosphere Model (CMAM), a fully interactive chemistry-climate model. The results show a good agreement between the measurements, model and the climatology. Thus, in order to account for the NO2 diurnal variation, we use CMAM to compare the NO2 measurements during MANTRA with the measurements done by the OSIRIS instrument onboard the Odin satellite, and by the SCIAMACHY and MIPAS instruments onboard the ENVISAT satellite, over Vanscoy. Since the satellite overpasses did not exactly coincide in time and location with the MANTRA balloon flight, CMAM is a valuable tool making such comparison possible. Such approach is particularly justified during late summer because of low dynamical variability with the stratosphere being largely under photochemical and radiative control.

  19. Modelled rainfall skill assessment against a 1000-year time/space isotope dendro-climatology for southern Africa

    Science.gov (United States)

    Woodborne, Stephan; Hall, Grant; Zhang, Qiong

    2016-04-01

    Palaeoclimate reconstruction using isotopic analysis of tree growth increments has yielded a 1000-year record of rainfall variability in southern Africa. Isotope dendro-climatology reconstructions from baobab trees (Adansonia digitata) provide evidence for rainfall variability from the arid Namib Desert and the Limpopo River Valley. Isotopic analysis of a museum specimen of a yellowwood tree (Podocarps falcatus) yields another record from the southwestern part of the subcontinent. Combined with the limited classic denro-climatologies available in the region these records yield palaeo-rainfall variability in the summer and winter rainfall zones as well as the hyper-arid zone over the last 1000 years. Coherent shifts in all of the records indicate synoptic changes in the westerlies, the inter-tropical convergence zone, and the Congo air boundary. The most substantial rainfall shift takes place at about 1600 CE at the onset of the Little Ice Age. Another distinctive feature of the record is a widespread phenomenon that occurs shortly after 1810 CE that in southern Africa corresponds with a widespread social upheaval known as the Difequane or Mfekane. Large scale forcing of the system includes sea-surface temperatures in the Agulhas Current, the El Nino Southern Oscillation and the Southern Annular Mode. The Little Ice Age and Mfekane climate shifts result from different forcing mechanisms, and the rainfall response in the different regions at these times do not have a fixed phase relationship. This complexity provides a good scenario to test climate models. A first order (wetter versus drier) comparison between each of the tree records and a 1000-year palaeoclimate model simulation for the Little Ice Age and Mfekane transitions demonstrates a generally good correspondence.

  20. A Central European precipitation climatology. Pt. I. Generation and validation of a high-resolution gridded daily data set (HYRAS)

    Energy Technology Data Exchange (ETDEWEB)

    Rauthe, Monika; Steiner, Heiko; Riediger, Ulf; Mazurkiewicz, Alex; Gratzki, Annegret [Deutscher Wetterdienst, Offenbach am Main (Germany)

    2013-10-15

    A new precipitation climatology (DWD/BfG-HYRAS-PRE) is presented which covers the river basins in Germany and neighbouring countries. In order to satisfy hydrological requirements, the gridded dataset has a high spatial resolution of 1 km{sup 2} and a daily temporal resolution that is based on up to 6200 precipitation stations within the spatial domain. The period of coverage extends from 1951 to 2006 for which gridded, daily precipitation fields were calculated from the station data using the REGNIE method. This is a combination between multiple linear regression considering orographical conditions and inverse distance weighting. One of the main attributes of the REGNIE method is the preservation of the station values for their respective grid cells. A detailed validation of the data set using cross-validation and Jackknifing showed both seasonally- and spatially-dependent interpolation errors. These errors, through further applications of the HYRAS data set within the KLIWAS project and other studies, provide an estimate of its certainty and quality. The mean absolute error was found to be less than 2 mm/day, but with both spatial and temporal variability. Additionally, the need for a high station network density was shown. Comparisons with other existing data sets show good agreement, with areas of orographical complexity displaying the largest differences within the domain. These errors are largely due to uncertainties caused by differences in the interpolation method, the station network density available, and the topographical information used. First climatological applications are presented and show the high potential of this new, high-resolution data set. Generally significant increases of up to 40% in winter precipitation and light decreases in summer are shown, whereby the spatial variability of the strength and significance of the trends is clearly illustrated. (orig.)

  1. Climatology and variability of trace gases in extratropical double-tropopause regions from MLS, HIRDLS, and ACE-FTS measurements

    Science.gov (United States)

    Schwartz, M. J.; Manney, G. L.; Hegglin, M. I.; Livesey, N. J.; Santee, M. L.; Daffer, W. H.

    2015-01-01

    Upper tropospheric and lower stratospheric measurements from the Aura Microwave Limb Sounder (MLS), the Aura High Resolution Dynamics Limb Sounder (HIRDLS), and the Atmospheric Chemistry Experiment-Fourier transform spectrometer (ACE-FTS) are used to present the first global climatological comparison of extratropical, nonpolar trace gas distributions in double-tropopause (DT) and single-tropopause (ST) regions. Stratospheric tracers, O3, HNO3, and HCl, have lower mixing ratios ˜2-8 km above the primary (lowermost) tropopause in DT than in ST regions in all seasons, with maximum Northern Hemisphere (NH) differences near 50% in winter and 30% in summer. Southern Hemisphere winter differences are somewhat smaller, but summer differences are similar in the two hemispheres. H2O in DT regions of both hemispheres shows strong negative anomalies in November through February and positive anomalies in July through October, reflecting the strong seasonal cycle in H2O near the tropical tropopause. CO and other tropospheric tracers examined have higher DT than ST values 2-7 km above the primary tropopause, with the largest differences in winter. Large DT-ST differences extend to high NH latitudes in fall and winter, with longitudinal maxima in regions associated with enhanced wave activity and subtropical jet variations. Results for O3 and HNO3 agree closely between MLS and HIRDLS, and differences from ACE-FTS are consistent with its sparse and irregular midlatitude sampling. Consistent signatures in climatological trace gas fields provide strong evidence that transport from the tropical upper troposphere into the layer between double tropopauses is an important pathway for stratosphere-troposphere exchange.

  2. First results on climatological response of Indian low latitude ionosphere to geomagnetic storms during solar cycle 23 and 24

    Science.gov (United States)

    Suresh, Sunanda; Dashora, Nirvikar

    2016-07-01

    For the first time, a climatological response of low latitude ionosphere to geomagnetic storms is presented using long term global ionospheric maps (GIM) data from June 1998 to June 2015 covering two solar cycles 23 and 24. The results are not only the first from Indian region but also the first around the globe to bring latitudinal character of daytime ionospheric storms with use of newly defined criteria. The results are presented for daytime forenoon and afternoon sectors under minor, moderate and major ionospheric storm categories based on minimum Dst index criterion. For the first time the effectiveness of storms is identified using monthly standard deviation as an indicator of the day-to-day variability in equatorial and low latitude ionosphere. Thus results on climatology are definitive and form a data base that would be comparable to statistical results from any other longitude and time. Seasonal statistics for total storms, effective positive and negative storms, and amplitude of mean seasonal perturbation in total electron content are obtained. Total and effective storms are found to be higher in solar cycle 23 than in 24 and only couple of effective storms occurred during low solar activity 2007-2009 that also in minor category. Afternoon sector is found to be favourable for occurrence of maximum number of effective positive storms. A latitudinal preference is found for a given storm to be effective in either time sectors. Equinoctial asymmetry in ionospheric response both in terms of occurrence and perturbation amplitude is found. September equinoxes are found to bear maximum total, effective positive and negative storms. Winters are found more prone to negative storms whereas summers have recorded minimum number of either of storms and minimum perturbation amplitudes.

  3. Recent climate change in the Arabian Peninsula: Seasonal rainfall and temperature climatology of Saudi Arabia for 1979-2009

    Science.gov (United States)

    Almazroui, Mansour; Islam, M. Nazrul; Jones, P. D.; Athar, H.; Rahman, M. Ashfaqur

    2012-07-01

    Attempts are made to study the seasonal climatology of the Arabian Peninsula, including the regional to station level information for Saudi Arabia for the period 1979-2009. The wet (November to April) and dry (June to September) season rainfall and temperature climatology are obtained from various data sources, namely, surface observations, CPC Merged Analysis of Precipitation (CMAP), Climatic Research Unit (CRU) and Tropical Rainfall Measuring Mission (TRMM). These gridded datasets detect the dry zone over the Rub Al-Khali, the world's largest sand desert, during the wet season. In this season, large rain belts exist north of 30°N and south of 15°N. During the dry season, the Arabian Peninsula is almost entirely dry north of 15°N but rain belts exist below this latitudinal boundary. Irrespective of the season or dataset used, a relatively heavy-rain area is obtained for the southwest of the Peninsula. The wet (dry) season temperature is highest over the western (middle to the northern) parts of the Peninsula. Surface observations indicate that, irrespective of season, rainfall insignificantly increased in the first period (1979-1993), and then significantly decreased in the second period (1994-2009). The decrease rate is 35.1 mm (5.5 mm) per decade during the wet (dry) season. The temperature over Saudi Arabia has increased significantly, and the increase rate is faster (0.72 °C per decade) in the dry season compared to the wet season (0.51 °C per decade).

  4. A multi-model analysis of the resolution influence on precipitation climatology in the Gulf Stream region

    Science.gov (United States)

    Feng, Xuelei; Huang, Bohua; Kirtman, Ben P.; Kinter, James L.; Chiu, Long S.

    2016-05-01

    Using climate simulations from coupled and uncoupled general circulation models, this study investigates the influence of horizontal resolution in both atmospheric and oceanic model components on the mean precipitation over the Gulf Stream (GS) region. For this purpose, three sets of model experiments are analyzed. The first two examine the effects of increasing horizontal resolution of an atmospheric general circulation model (AGCM) gradually from 100 to 10 km under fixed oceanic settings. Specifically, the AGCM is either forced with prescribed observed sea surface temperature (SST) (the first case) or coupled to a non-eddy-resolving ocean general circulation model (OGCM) at a fixed horizontal resolution near 100 km (the second case). The third set of experiments examines the effects of the oceanic resolution with a pair of long-term simulations by another coupled ocean-atmosphere general circulation model (CGCM), in which the OGCM is run respectively at non-eddy-resolving (100 km) and eddy-resolving (10 km) resolutions, while the AGCM resolution remains fixed at 50 km for both runs. In general, all simulations qualitatively reproduce the gross features of the mean GS precipitation and its annual cycle. At similar AGCM resolutions, the uncoupled models produce a GS rain band that is more realistic in both structure and strength compared to the coupled models with non-eddy-resolving oceans. This is because the prescribed observed SST better represents the gradient near the oceanic front than the non-eddy-resolving OGCMs simulate. An increase from the baseline AGCM resolution produces enhanced climatological GS precipitation, both large-scale and convective, with the latter more tightly confined to the oceanic front. The enhancement, however, is moderate and further increases in resolution achieves diminishing results. On the other hand, an increase in oceanic resolution from non-eddy-resolving to eddy resolving scheme results in more consistent simulations with

  5. Assessment of daily reference evapotranspiration in Sicily by means of POWER-NASA agro-climatology archive

    Science.gov (United States)

    Negm, Amro; Jabro, Jay; Provenzano, Giuseppe

    2016-04-01

    The importance of evapotranspiration, ET, processes has long been recognized in many disciplines, including hydrologic and drainage studies as well as for irrigation system design and management. A wide number of equations have been proposed to estimate crop reference evapotranspiration, ET0, based on the variables affecting the process. When a full data set of climate variables is available, the Food and Agriculture Organization (FAO) of the United Nations recommended to use the physically based FAO-56 Penman-Monteith equation. The lack of climate variables and particularly of solar radiation has led several researchers to propose simplified ET0 estimation equations using a limited number of climate variables. These equations, however, need site-specific validation prior to their use and cannot be generalized. Recently, the American National Aeronautics and Space Administration (NASA), created an efficient and open access agro-climatology archive in the frame of the Prediction Of Worldwide Energy Resource (POWER) project containing, on global scale, a long-series of meteorological variables and surface solar energy fluxes. The main objective of the research was to assess the suitability of POWER-NASA open access archive to estimate daily reference evapotranspiration, ET0, in Sicily, for the period 2006-2014. Daily ET0 were evaluated according to FAO-56 PM equation, by considering the POWER-NASA database characterized by a grid resolution of 1° latitude × 1° longitude, as well as the climate data measured on the ground, by a network of 36 meteorological stations installed in Sicily and belonging to the Agro-meteorological Information Service (SIAS). After comparing the climate data available in both databases (minimum, maximum and average air temperature and relative air humidity, wind speed, solar radiation and air pressure), a statistical comparison was also carried out on ET0 values estimated with the FAO-56 PM equation. The analysis showed a good correlation

  6. Nitric acid in the stratosphere based on Odin observations from 2001 to 2009 – Part 1: A global climatology

    Directory of Open Access Journals (Sweden)

    J. Urban

    2009-09-01

    Full Text Available The Sub-Millimetre Radiometer (SMR on board the Odin satellite, launched in February 2001, observes thermal emissions of stratospheric nitric acid (HNO3 originating from the Earth limb in a band centred at 544.6 GHz. Height-resolved measurements of the global distribution of nitric acid in the stratosphere were performed approximately on two observation days per week. An HNO3 climatology based on more than 7 years of observations from August 2001 to April 2009 covering the vertical range between typically ~19 and 45 km (~1.5–60 hPa or ~500–1800 K in terms of potential temperature was created. The study highlights the spatial and seasonal variation of nitric acid in the stratosphere, characterised by a pronounced seasonal cycle at middle and high latitudes with maxima during late fall and minima during spring, strong denitrification in the lower stratosphere of the Antarctic polar vortex during winter (the irreversible removal of NOy by the sedimentation of cloud particles containing HNO3, as well as large quantities of HNO3 formed every winter at high-latitudes in the middle and upper stratosphere. A strong inter-annual variability is observed in particular at high latitudes. A comparison with a stratospheric HNO3 climatology, based on over 7 years of UARS/MLS (Upper Atmosphere Research Satellite/Microwave Limb Sounder measurements from the 1990s, shows good consistency and agreement of the main morphological features in the potential temperature range ~465 to ~960 K, if the different characteristics of the data sets such as the better altitude resolution of Odin/SMR as well as the slightly different altitude ranges are considered. Odin/SMR reaches higher up and UARS/MLS lower down in the stratosphere. An overview from 1991 to 2009 of stratospheric nitric acid is provided (with a short gap between 1998 and 2001, if the global measurements of both experiments are taken together.

  7. Toward a combined SAGE II-HALOE aerosol climatology: an evaluation of HALOE version 19 stratospheric aerosol extinction coefficient observations

    Directory of Open Access Journals (Sweden)

    L. W. Thomason

    2012-09-01

    Full Text Available Herein, the Halogen Occultation Experiment (HALOE aerosol extinction coefficient data is evaluated in the low aerosol loading period after 1996 as the first necessary step in a process that will eventually allow the production of a combined HALOE/SAGE II (Stratospheric Aerosol and Gas Experiment aerosol climatology of derived aerosol products including surface area density. Based on these analyses, it is demonstrated that HALOE's 3.46 μm is of good quality above 19 km and suitable for scientific applications above that altitude. However, it is increasingly suspect at lower altitudes and should not be used below 17 km under any circumstances after 1996. The 3.40 μm is biased by about 10% throughout the lower stratosphere due to the failure to clear NO2 but otherwise appears to be a high quality product down to 15 km. The 2.45 and 5.26 μm aerosol extinction coefficient measurements are clearly biased and should not be used for scientific applications after the most intense parts of the Pinatubo period. Many of the issues in the aerosol data appear to be related to either the failure to clear some interfering gas species or doing so poorly. For instance, it is clear that the 3.40 μm aerosol extinction coefficient measurements can be improved through the inclusion of an NO2 correction and could, in fact, end up as the highest quality overall HALOE aerosol extinction coefficient measurement. It also appears that the 2.45 and 5.26 μm channels may be improved by updating the Upper Atmosphere Pilot Database which is used as a resource for the removal of gas species otherwise not available from direct HALOE measurements. Finally, a simple model to demonstrate the promise of mixed visible/infrared aerosol extinction coefficient ensembles for the retrieval of bulk aerosol properties demonstrates that a combined HALOE/SAGE II aerosol climatology is feasible and may represent a substantial improvement over independently derived

  8. Climatological monitoring of territory affected by construction of the Danube hydroelectric power project and evaluation of initial impact

    International Nuclear Information System (INIS)

    Climatological study revealed significance of regional time trends of critical climatic elements in the period 1901-1994. From the point of view. From the point of climate development, all changes of climatic elements acted negatively and unidirectional in the sense of increasing requirements for soil moisture, decreasing water content in the upper layers of soil, decreasing ground water levels and discharges in rivers. Climatology has to disposition results of long series of measurements, while another scientific disciplines are lacking such precise data. That is why some changes of regional character might be inappropriately ascribed to local anthropogenic interventions of natural environment. From the results presented in the study it follows that regional trends of air and potential evapotranspiration (PE) are unambiguously increasing. Within 90 years (1901-1990), air temperature rose by about 0,8 grad C, while PE increased by about 14%. In warm half year (IV-IX), air temperature increased by 0,5 grad C and PE by 11%. Trend of precipitation totals, sunshine duration and relative air humidity was decreasing, precipitation dropped by 15%, sunshine duration was shorter by 2% and relative humidity was lower by 5%. These trends characteristics suggest that in the course of the last 90 years, regional climate was subjected to changes that have significantly affected several factors of environment. Rise in air temperature and at the same time drop in precipitation and relative humidity correspond well to increase of PE. Due to these facts, requirements for soil moisture increased. As consequence, soil humidity, level of ground water and river discharges decreased in a larger area. Entire 1991-1993 period was above normal as to the temperature, especially in summer. In the rest of territory, level of air pollution corresponded to regional middle European background. Hydroelectric Power Structures will not influence directly level of air pollution, however, production

  9. Bayesian Spatiotemporal Pattern and Eco-climatological Drivers of Striped Skunk Rabies in the North Central Plains.

    Science.gov (United States)

    Raghavan, Ram K; Hanlon, Cathleen A; Goodin, Douglas G; Davis, Rolan; Moore, Michael; Moore, Susan; Anderson, Gary A

    2016-04-01

    Striped skunks are one of the most important terrestrial reservoirs of rabies virus in North America, and yet the prevalence of rabies among this host is only passively monitored and the disease among this host remains largely unmanaged. Oral vaccination campaigns have not efficiently targeted striped skunks, while periodic spillovers of striped skunk variant viruses to other animals, including some domestic animals, are routinely recorded. In this study we evaluated the spatial and spatio-temporal patterns of infection status among striped skunk cases submitted for rabies testing in the North Central Plains of US in a Bayesian hierarchical framework, and also evaluated potential eco-climatological drivers of such patterns. Two Bayesian hierarchical models were fitted to point-referenced striped skunk rabies cases [n = 656 (negative), and n = 310 (positive)] received at a leading rabies diagnostic facility between the years 2007-2013. The first model included only spatial and temporal terms and a second covariate model included additional covariates representing eco-climatic conditions within a 4km2 home-range area for striped skunks. The better performing covariate model indicated the presence of significant spatial and temporal trends in the dataset and identified higher amounts of land covered by low-intensity developed areas [Odds ratio (OR) = 3.41; 95% Bayesian Credible Intervals (CrI) = 2.08, 3.85], higher level of patch fragmentation (OR = 1.70; 95% CrI = 1.25, 2.89), and diurnal temperature range (OR = 0.54; 95% CrI = 0.27, 0.91) to be important drivers of striped skunk rabies incidence in the study area. Model validation statistics indicated satisfactory performance for both models; however, the covariate model fared better. The findings of this study are important in the context of rabies management among striped skunks in North America, and the relevance of physical and climatological factors as risk factors for skunk to human rabies transmission and the

  10. Bayesian Spatiotemporal Pattern and Eco-climatological Drivers of Striped Skunk Rabies in the North Central Plains

    Science.gov (United States)

    Raghavan, Ram K.; Hanlon, Cathleen A.; Goodin, Douglas G.; Anderson, Gary A.

    2016-01-01

    Striped skunks are one of the most important terrestrial reservoirs of rabies virus in North America, and yet the prevalence of rabies among this host is only passively monitored and the disease among this host remains largely unmanaged. Oral vaccination campaigns have not efficiently targeted striped skunks, while periodic spillovers of striped skunk variant viruses to other animals, including some domestic animals, are routinely recorded. In this study we evaluated the spatial and spatio-temporal patterns of infection status among striped skunk cases submitted for rabies testing in the North Central Plains of US in a Bayesian hierarchical framework, and also evaluated potential eco-climatological drivers of such patterns. Two Bayesian hierarchical models were fitted to point-referenced striped skunk rabies cases [n = 656 (negative), and n = 310 (positive)] received at a leading rabies diagnostic facility between the years 2007–2013. The first model included only spatial and temporal terms and a second covariate model included additional covariates representing eco-climatic conditions within a 4km2 home-range area for striped skunks. The better performing covariate model indicated the presence of significant spatial and temporal trends in the dataset and identified higher amounts of land covered by low-intensity developed areas [Odds ratio (OR) = 3.41; 95% Bayesian Credible Intervals (CrI) = 2.08, 3.85], higher level of patch fragmentation (OR = 1.70; 95% CrI = 1.25, 2.89), and diurnal temperature range (OR = 0.54; 95% CrI = 0.27, 0.91) to be important drivers of striped skunk rabies incidence in the study area. Model validation statistics indicated satisfactory performance for both models; however, the covariate model fared better. The findings of this study are important in the context of rabies management among striped skunks in North America, and the relevance of physical and climatological factors as risk factors for skunk to human rabies transmission and

  11. Evaluation of High-Resolution Satellite Rainfall Products over the Nile Basin for Climatologic and Hydrologic Applications

    Science.gov (United States)

    Habib, E. H.; Haile, A.; Elsaadani, M.; Elshamy, M. E.; Amin, D.; Kuligowski, R. J.

    2010-12-01

    This study presents an evaluation of high-resolution rainfall estimates over the Nile Basin in Africa. The focus of the evaluation is two-fold: (1) can the satellite-rainfall products capture the overall climatological patterns and trends over the basin?, and (2) how and under what circumstances do these products support hydrologic predictions when being used as to drive a basin-wide hydrologic forecasting model? The products under examination are: the ‘Tropical Rainfall Measuring Mission (TRMM) and other sources’ (TRMM-3B42) product, and the National Oceanographic and Atmospheric Administration Climate Prediction Center (NOAA-CPC) product which is based on the CPC morphing technique (CMORPH). Over most parts of the Nile basin that are situated north of the equator, the CMORPH product shows a wet bias while the TRMM-3B42 product shows a dry bias. The estimates from both products were within the range of the climatologic records over parts of the basin around the equator. Both products reproduced the diurnal cycle of rain occurrence over the Lake Tana basin (the source of the Blue Nile) except over the mountains and the Lake shore. However, the TRMM-3B42 product underestimated the rainfall amounts in this basin. The satellite products captured the contrasting patterns of the diurnal cycles of rain occurrence and amount over the surroundings of Lake Victoria (the source of the White Nile). The second part of the evaluation focused on evaluating the possible improvements in streamflow predictions that are produced by the Nile Forecasting System (NFS) operated by the Nile Forecasting Center in Cairo, Egypt. The results suggest that that the performance of a basin-wide hydrologic model of the Nile river significantly improves when the CMORPH estimates serve as the main rainfall input compared to IR-based estimates traditionally used in the NFS model. In the Blue Nile basin, the relative volume error of the simulated flow decreased from -40 % when IR-based estimates

  12. A climatological perspective of deep convection penetrating the TTL during the Indian summer monsoon from the AVHRR and MODIS instruments

    Directory of Open Access Journals (Sweden)

    A. Devasthale

    2010-05-01

    Full Text Available The impact of very deep convection on the water budget and thermal structure of the tropical tropopause layer is still not well quantified, not least because of limitations imposed by the available observation techniques. Here, we present detailed analysis of the climatology of the cloud top brightness temperatures as indicators of deep convection during the Indian summer monsoon, and the variations therein due to active and break periods. We make use of the recently newly processed data from the Advanced Very High Resolution Radiometer (AVHRR at a nominal spatial resolution of 4 km. Using temperature thresholds from the Atmospheric Infrared Sounder (AIRS, the AVHRR brightness temperatures are converted to climatological mean (2003–2008 maps of cloud amounts at 200, 150 and 100 hPa. Further, we relate the brightness temperatures to the level of zero radiative heating, which may allow a coarse identification of convective detrainment that will subsequently ascend into the stratosphere. The AVHRR data for the period 1982–2006 are used to document the differences in deep convection between active and break conditions of the monsoon. The analysis of AVHRR data is complemented with cloud top pressure and optical depth statistics (for the period 2003–2008 from the Moderate Resolution Imaging Spectroradiometer (MODIS onboard Aqua satellite. Generally, the two sensors provide a very similar description of deep convective clouds.

    Our analysis shows that most of the deep convection occurs over the Bay of Bengal and central northeast India. Very deep convection over the Tibetan plateau is comparatively weak, and may play only a secondary role in troposphere-to-stratosphere transport. The deep convection over the Indian monsoon region is most frequent in July/August, but the very highest convection (coldest tops, penetrating well into the TTL occurs in May/June. Large variability in convection reaching the TTL is due to monsoon break

  13. A climatological perspective of deep convection penetrating the TTL during the Indian summer monsoon from the AVHRR and MODIS instruments

    Directory of Open Access Journals (Sweden)

    A. Devasthale

    2010-02-01

    Full Text Available The impact of very deep convection on the water budget and thermal structure of the tropical tropopause layer is still not well quantified, not least because of limitations imposed by the available observation techniques. Here, we present detailed analysis of the climatology of the cloud top brightness temperatures as indicators of deep convection during the Indian summer monsoon, and the variations therein due to active and break periods. We make use of the recently newly processed data from the Advanced Very High Resolution Radiometer (AVHRR at a nominal spatial resolution of 4 km. Using temperature thresholds from the Atmospheric Infrared Sounder (AIRS, the AVHRR brightness temperatures are converted to climatological mean (2003–2008 maps of cloud amounts at 200, 150 and 100 hPa. Further, we relate the brightness temperatures to the level of zero radiative heating, which may allow a coarse identification of convective detrainment that will subsequently ascend into the stratosphere. The AVHRR data for the period 1982–2006 are used to document the differences in deep convection between active and break conditions of the monsoon. The analysis of AVHRR data is complemented with cloud top pressure and optical depth statistics (for the period 2003–2008 from the Moderate Resolution Imaging Spectroradiometer (MODIS onboard Aqua satellite. Generally, the two sensors provide a very similar description of deep convective clouds.

    Our analysis shows that most of the deep convection occurs over the Bay of Bengal and Central Northeast India. Very deep convection over the Tibetan plateau is comparatively weak, and may play only a secondary role in troposphere-to-stratosphere transport. The deep convection over the Indian monsoon region is most frequent in July/August, but the very highest convection (coldest tops, penetrating well into the TTL occurs in May/June. Large variability in convection reaching the TTL is due to monsoon break

  14. Decadal Changes in Climatological Intraseasonal Fluctuation of Subseasonal Evolution of Summer Precipitation over the Korean Peninsula in the mid-1990s

    Institute of Scientific and Technical Information of China (English)

    WonMoo KIM; Jong-Ghap JHUN; Kyung-Ja HA; Masahide KIMOTO

    2011-01-01

    Decadal changes in the subseasonal evolution and the phase-locked climatological intraseasonal fluctuation of summertime rainfall over the Korean Peninsula before and after the mid-1990s are investigated. The activity and the migration speed of the monsoon rain band over the East Asian region are altered in the recent decade, resulting in the drier conditions in late spring and the earlier onset of Changma. In early August when a climatological monsoon break was clear in the earlier decade, the precipitation has increased dramatically with a meridional coherency. The response to the enhanced convection over the South China Sea and southeastern China provides a favorable condition for more precipitation in early August through the changes in moisture transport and tropical cyclone passage.

  15. Decadal Changes in Climatological Intraseasonal Fluctuation of Subseasonal Evolution of Summer Precipitation over the Korean Peninsula in the mid-1990s

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Decadal changes in the subseasonal evolution and the phase-locked climatological intraseasonal fluctuation of summertime rainfall over the Korean Peninsula before and after the mid-1990s are investigated.The activity and the migration speed of the monsoon rain band over the East Asian region are altered in the recent decade,resulting in the drier conditions in late spring and the earlier onset of Changma.In early August when a climatological monsoon break was clear in the earlier decade,the precipitation has increased dramatically with a meridional coherency.The response to the enhanced convection over the South China Sea and southeastern China provides a favorable condition for more precipitation in early August through the changes in moisture transport and tropical cyclone passage.

  16. Modeling 1993-2008 climatology of seasonal general circulation and thermal structure in the Great Lakes using FVCOM

    Science.gov (United States)

    Bai, Xuezhi; Wang, Jia; Schwab, David J.; Yang, Yi; Luo, Lin; Leshkevich, George A.; Liu, Songzhi

    2013-05-01

    An unstructured Finite Volume Coastal Ocean Model was applied to all five Great Lakes simultaneously to simulate circulation and thermal structure from 1993 to 2008. Model results are compared to available observations of currents and temperature and previous modeling work. Maps of climatological circulation for all five Great lakes are presented. Winter currents show a two-gyre type circulation in Lakes Ontario and Erie and one large-scale cyclonic circulation in Lakes Michigan, Huron, and Superior. During the summer, a cyclonic circulation remains in Lakes Superior; a primarily cyclonic circulation dominates upper and central Lake Huron; Lake Ontario has a single cyclonic circulation, while circulation in the central basin of Lake Erie remains two-gyre type; Lake Michigan has a cyclonic gyre in the north and an anti-cyclonic one in the south. The temperature profile during the summer is well simulated when a surface wind-wave mixing scheme is included in the model. Main features of the seasonal evolution of water temperature, such as inverse temperature stratification during the winter, the spring and autumn overturn, the thermal bar, and the stratification during summer are well reproduced. The lakes exhibit significant annual and interannual variations in current speed and temperature.

  17. Basin-scale wind transport during the MILAGRO field campaign and comparison to climatology using cluster analysis

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2008-03-01

    Full Text Available The MILAGRO field campaign was a multi-agency international collaborative project to evaluate the regional impacts of the Mexico City air pollution plume as a means of understanding urban impacts on the global climate. Mexico City lies on an elevated plateau with mountains on three sides and has complex mountain and surface-driven wind flows. This paper asks what the wind transport was in the basin during the field campaign and how representative it was of the climatology. Surface meteorology and air quality data, radiosondes and radar wind profiler data were collected at sites in the basin and its vicinity. Cluster analysis was used to identify the dominant wind patterns both during the campaign and within the past 10 years of operational data from the warm dry season. Our analysis shows that March 2006 was representative of typical flow patterns experienced in the basin. Six episode types were identified for the basin-scale circulation providing a way of interpreting atmospheric chemistry and particulate data collected during the campaign. Decoupling between surface winds and those aloft had a strong influence in leading to convection and poor air quality episodes. Hourly characterisation of wind circulation during the MILAGRO, MCMA-2003 and IMADA field campaigns enables the comparisons of similar air pollution episodes and the evaluation of the impact of wind transport on measurements of the atmospheric chemistry taking place in the basin.

  18. Basin-scale wind transport during the MILAGRO field campaign and comparison to climatology using cluster analysis

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2007-09-01

    Full Text Available The MILAGRO field campaign was a multi-agency international collaborative project to evaluate the regional impacts of the Mexico City air pollution plume as a means of understanding urban impacts on the global climate. Mexico City lies on an elevated plateau with mountains on three sides and has complex mountain and surface-driven wind flows. This paper asks what the wind transport was in the basin during the field campaign and how representative it was of the climatology. Surface meteorology and air quality data, radiosoundings and radar wind profiler data were collected at sites in the basin and its vicinity. Cluster analysis is used to identify the dominant wind patterns both during the campaign and within the past 10 years of operational data from the warm dry season. Our analysis shows that March 2006 was representative of typical flow patterns experienced in the basin. Six episode types were identified for the basin scale circulation providing a way of interpreting atmospheric chemistry and particulate data collected during the campaign. Decoupling between surface winds and those aloft had a strong influence in leading to convection and poor air quality episodes. Hourly characterisation of wind circulation during the MILAGRO, MCMA-2003 and IMADA field campaigns will enable the comparisons of similar air pollution episodes and the evaluation of the impact of wind transport on measurements of the atmospheric chemistry taking place in the basin.

  19. Climatology of Mid-latitude Ionospheric Disturbances from the Very Large Array Low-frequency Sky Survey

    CERN Document Server

    Helmboldt, J F; Cotton, W D

    2012-01-01

    The results of a climatological study of ionospheric disturbances derived from observations of cosmic sources from the Very Large Array (VLA) Low-frequency Sky Survey (VLSS) are presented. We have used the ionospheric corrections applied to the 74 MHz interferometric data within the VLSS imaging process to obtain fluctuation spectra for the total electron content (TEC) gradient on spatial scales from a few to hundreds of kilometers and temporal scales from less than one minute to nearly an hour. The observations sample nearly all times of day and all seasons. They also span latitudes and longitudes from 28 deg. N to 40 deg. N and 95 deg. W to 114 deg. W, respectively. We have binned and averaged the fluctuation spectra according to time of day, season, and geomagnetic (Kp index) and solar (F10.7) activity. These spectra provide a detailed, multi-scale account of seasonal and intraday variations in ionospheric activity with wavelike structures detected at wavelengths between about 35 and 250 km. In some cases,...

  20. Towards a Model Climatology of Relative Humidity in the Upper Troposphere for Estimation of Contrail and Contrail-Induced Cirrus

    Science.gov (United States)

    Selkirk, Henry B.; Manyin, M.; Ott, L.; Oman, L.; Benson, C.; Pawson, S.; Douglass, A. R.; Stolarski, R. S.

    2011-01-01

    The formation of contrails and contrail cirrus is very sensitive to the relative humidity of the upper troposphere. To reduce uncertainty in an estimate of the radiative impact of aviation-induced cirrus, a model must therefore be able to reproduce the observed background moisture fields with reasonable and quantifiable fidelity. Here we present an upper tropospheric moisture climatology from a 26-year ensemble of simulations using the GEOS CCM. We compare this free-running model's moisture fields to those obtained from the MLS and AIRS satellite instruments, our most comprehensive observational databases for upper tropospheric water vapor. Published comparisons have shown a substantial wet bias in GEOS-5 assimilated fields with respect to MLS water vapor and ice water content. This tendency is clear as well in the GEOS CCM simulations. The GEOS-5 moist physics in the GEOS CCM uses a saturation adjustment that prevents supersaturation, which is unrealistic when compared to in situ moisture observations from MOZAIC aircraft and balloon sondes as we will show. Further, the large-scale satellite datasets also consistently underestimate super-saturation when compared to the in-situ observations. We place these results in the context of estimates of contrail and contrail cirrus frequency.

  1. Comparative climatological study of large-scale traveling ionospheric disturbances over North America and China in 2011-2012

    Science.gov (United States)

    Ding, Feng; Wan, Weixing; Li, Qiang; Zhang, Rui; Song, Qian; Ning, Baiqi; Liu, Libo; Zhao, Biqiang; Xiong, Bo

    2014-01-01

    This paper describes a comparative study of the climatology of large-scale traveling ionospheric disturbances (LSTIDs) over North America and China based on observations obtained in 2011-2012 using two GPS networks characterized by dense regional coverage. We identified a total of 390 LSTIDs in China and 363 events in North America. These can be categorized into three types, namely south, north, and westward propagating LSTIDs. The southward LSTIDs over North America show similar diurnal and seasonal variations to those of geomagnetic disturbances, but the southward LSTIDs over China do not show such variations. The occurrence of southward LSTIDs over China increases at ~1-2 h after the time of geomagnetic activity maximum; this increase lasts several hours until the geomagnetic minimum, which happens during the local evening. The southward LSTIDs over North America show a semiannual variation with two peaks in March and October, while the southward LSTIDs over China show a major peak in January. Northward LSTIDs occur much less frequently than their southward counterparts, and they are mainly observed in China. They mostly occur during geomagnetic activity maximum, indicating a possible relation with the degree of geomagnetic activity. Westward LSTIDs are seen in both regions during local sunrise and may be excited by the moving solar terminator. No relationship was found between these latter LSTIDs and the geomagnetic disturbances. The propagation direction of westward events changed from northwestward during winter solstice to southwestward at summer solstice. This is consistent with the seasonal orientation of the solar terminator.

  2. Santa Ana Winds of Southern California: Their Climatology and Variability Spanning 6.5 Decades from Regional Dynamical Modelling

    Science.gov (United States)

    Guzman-Morales, J.; Gershunov, A.

    2015-12-01

    Santa Ana Winds (SAWs) are an integral feature of the regional climate of Southern California/Northern Baja California region. In spite of their tremendous episodic impacts on the health, economy and mood of the region, climate-scale behavior of SAW is poorly understood. In the present work, we identify SAWs in mesoscale dynamical downscaling of a global reanalysis product and construct an hourly SAW catalogue spanning 65 years. We describe the long-term SAW climatology at relevant time-space resolutions, i.e, we developed local and regional SAW indices and analyse their variability on hourly, daily, annual, and multi-decadal timescales. Local and regional SAW indices are validated with available anemometer observations. Characteristic behaviors are revealed, e.g. the SAW intensity-duration relationship. At interdecadal time scales, we find that seasonal SAW activity is sensitive to prominent large-scale low-frequency modes of climate variability rooted in the tropical and north Pacific ocean-atmosphere system that are also known to affect the hydroclimate of this region. Lastly, we do not find any long-term trend in SAW frequency and intensity as previously reported. Instead, we identify a significant long-term trend in SAW behavior whereby contribution of extreme SAW events to total seasonal SAW activity has been increasing at the expense of moderate events. These findings motivate further investigation on SAW evolution in future climate and its impact on wildfires.

  3. Data summary for evaluation of the transport and diffusion climatology of the United States east and Gulf Coasts

    Energy Technology Data Exchange (ETDEWEB)

    Raynor, G S; Hayes, J V

    1979-07-01

    A study of the atmospheric transport and diffusion climatology of the United States east and Gulf coasts was conducted as part of a larger coastal meteorology and diffusion program to aid in planning and site selection. Synoptic data were obtained from thirty coastal stations from Maine to Texas and analyzed in terms of conditions important to emission transport and diffusion. The thirty stations included four pairs with one of each pair at a greater distance from the coast than the other but near the same latitude. For each station, wind directions were classified into eight groups with reference to orientation of the local coastline. For some studies, these were combined into three groups - onshore, alongshore and offshore. Wind speeds were divided into four classes. A diffusion class for each observation was computed by a modified Pasquill method. This gave eight classes which were combined into three - unstable, neutral and stable - for some studies. A diffusion rating was derived from combinations of wind speed and diffusion class ranging from very good to very poor. Finally, the joint frequency distributions of wind direction and diffusion rating were calculated for each station. Data were then classified by season, time of day, wind direction, wind speed, diffusion class and combinations of these variables and the percent of hours in each subgroup determined. Results are presented in a series of tables.

  4. South American Climatology and Impacts of El Niño in NCEP’s CFSR Data

    Directory of Open Access Journals (Sweden)

    Timothy Paul Eichler

    2013-01-01

    Full Text Available Understanding regional climate variability is necessary in order to assess the impacts of climate change. Until recently, the best methods for evaluating regional climate variability were via observation networks and coarse-gridded reanalysis datasets. However, the recent development of high-resolution reanalysis datasets offers an opportunity to better evaluate the climatologically diverse continent of South America. This study compares NCEP’s CFS reanalysis dataset with NCEP’s coarser-resolution reanalysis II dataset to determine if CFS reanalysis improves our ability to represent the regional climate of South America. Our results show several regional differences between the CFSR and Re2 data, especially in areas of large topographical gradients. A comparison with the University of Delaware and TRMM precipitation datasets lends credence to some of these differences, such as heavier precipitation associated with anomalous 925 hPa westerlies over northwestern Peru and Ecuador during El Niño. However, our results also stress that caution is advised when using reanalysis data to assess regional climate variability, especially in areas of large topographical gradient such as the Andes. Our results establish a baseline to better study climate change, especially given the release of IPCC AR5 model simulations.

  5. The SPARC Data Initiative: Comparison of upper troposphere/lower stratosphere ozone climatologies from limb-viewing instruments and the nadir-viewing Tropospheric Emission Spectrometer

    OpenAIRE

    J. L. Neu; Hegglin, M. I.; Tegtmeier, Susann; Bourassa, A.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A; A. Rozanov; Toohey, M.; T. von Clarmann; K. A. Walker; Worden, J. R.

    2014-01-01

    We present the first comprehensive intercomparison of currently available satellite ozone climatologies in the upper troposphere/lower stratosphere (UTLS) (300-70hPa) as part of the Stratosphere-troposphere Processes and their Role in Climate (SPARC) Data Initiative. The Tropospheric Emission Spectrometer (TES) instrument is the only nadir-viewing instrument in this initiative, as well as the only instrument with a focus on tropospheric composition. We apply the TES observational operator to ...

  6. Tropospheric ozonesonde profiles at long-term U.S. monitoring sites: 1. A climatology based on self-organizing maps

    Science.gov (United States)

    Stauffer, Ryan M.; Thompson, Anne M.; Young, George S.

    2016-02-01

    Sonde-based climatologies of tropospheric ozone (O3) are vital for developing satellite retrieval algorithms and evaluating chemical transport model output. Typical O3 climatologies average measurements by latitude or region, and season. A recent analysis using self-organizing maps (SOM) to cluster ozonesondes from two tropical sites found that clusters of O3 mixing ratio profiles are an excellent way to capture O3 variability and link meteorological influences to O3 profiles. Clusters correspond to distinct meteorological conditions, e.g., convection, subsidence, cloud cover, and transported pollution. Here the SOM technique is extended to four long-term U.S. sites (Boulder, CO; Huntsville, AL; Trinidad Head, CA; and Wallops Island, VA) with 4530 total profiles. Sensitivity tests on k-means algorithm and SOM justify use of 3 × 3 SOM (nine clusters). At each site, SOM clusters together O3 profiles with similar tropopause height, 500 hPa height/temperature, and amount of tropospheric and total column O3. Cluster means are compared to monthly O3 climatologies. For all four sites, near-tropopause O3 is double (over +100 parts per billion by volume; ppbv) the monthly climatological O3 mixing ratio in three clusters that contain 13-16% of profiles, mostly in winter and spring. Large midtropospheric deviations from monthly means (-6 ppbv, +7-10 ppbv O3 at 6 km) are found in two of the most populated clusters (combined 36-39% of profiles). These two clusters contain distinctly polluted (summer) and clean O3 (fall-winter, high tropopause) profiles, respectively. As for tropical profiles previously analyzed with SOM, O3 averages are often poor representations of U.S. O3 profile statistics.

  7. An assessment of the quality of aerosol retrievals over the Red Sea and evaluation of the climatological cloud-free dust direct radiative effect in the region

    KAUST Repository

    Brindley, H.

    2015-10-20

    Ground-based and satellite observations are used in conjunction with the Rapid Radiative Transfer Model (RRTM) to assess climatological aerosol loading and the associated cloud-free aerosol direct radiative effect (DRE) over the Red Sea. Aerosol optical depth (AOD) retrievals from the Moderate Resolution Imaging Spectroradiometer and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instruments are first evaluated via comparison with ship-based observations. Correlations are typically better than 0.9 with very small root-mean-square and bias differences. Calculations of the DRE along the ship cruises using RRTM also show good agreement with colocated estimates from the Geostationary Earth Radiation Budget instrument if the aerosol asymmetry parameter is adjusted to account for the presence of large particles. A monthly climatology of AOD over the Red Sea is then created from 5 years of SEVIRI retrievals. This shows enhanced aerosol loading and a distinct north to south gradient across the basin in the summer relative to the winter months. The climatology is used with RRTM to estimate the DRE at the top and bottom of the atmosphere and the atmospheric absorption due to dust aerosol. These climatological estimates indicate that although longwave effects can reach tens of W m−2, shortwave cooling typically dominates the net radiative effect over the Sea, being particularly pronounced in the summer, reaching 120 W m−2 at the surface. The spatial gradient in summertime AOD is reflected in the radiative effect at the surface and in associated differential heating by aerosol within the atmosphere above the Sea. This asymmetric effect is expected to exert a significant influence on the regional atmospheric and oceanic circulation.

  8. 16 year climatology of cirrus clouds over a tropical station in southern India using ground and space-based lidar observations

    Directory of Open Access Journals (Sweden)

    A. K. Pandit

    2015-06-01

    Full Text Available 16 year (1998–2013 climatology of cirrus clouds and their macrophysical (base height, top height and geometrical thickness and optical properties (cloud optical thickness observed using a ground-based lidar over Gadanki (13.5° N, 79.2° E, India, is presented. The climatology obtained from the ground-based lidar is compared with the climatology obtained from seven and half years (June 2006–December 2013 of Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP observations. A very good agreement is found between the two climatologies in spite of their opposite viewing geometries and difference in sampling frequencies. Nearly 50–55% of cirrus clouds were found to possess geometrical thickness less than 2 km. Ground-based lidar is found to detect more number of sub-visible clouds than CALIOP which has implications for global warming studies as sub-visible cirrus clouds have significant positive radiative forcing. Cirrus clouds with mid-cloud temperatures between −50 to −70 °C have a mean geometrical thickness greater than 2 km in contrast to the earlier reported value of 1.7 km. Trend analyses reveal a statistically significant increase in the altitude of sub-visible cirrus clouds which is consistent with the recent climate model simulations. Also, the fraction of sub-visible cirrus cloud is found to be increasing during the last sixteen years (1998 to 2013 which has implications to the temperature and water vapour budget in the tropical tropopause layer.

  9. 4 km NODC/RSMAS AVHRR Pathfinder v5 Seasonal and Annual Day-Night Sea Surface Temperature Climatologies for 1982-2009 for the Gulf of Mexico (NODC Accession 0072888)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains a set of sea surface temperature climatologies for the Gulf of Mexico (GOM), derived from the AVHRR Pathfinder Version 5 sea surface...

  10. Sensitivity of Global Sea-Air CO2 Flux to Gas Transfer Algorithms, Climatological Wind Speeds, and Variability of Sea Surface Temperature and Salinity

    Science.gov (United States)

    McClain, Charles R.; Signorini, Sergio

    2002-01-01

    Sensitivity analyses of sea-air CO2 flux to gas transfer algorithms, climatological wind speeds, sea surface temperatures (SST) and salinity (SSS) were conducted for the global oceans and selected regional domains. Large uncertainties in the global sea-air flux estimates are identified due to different gas transfer algorithms, global climatological wind speeds, and seasonal SST and SSS data. The global sea-air flux ranges from -0.57 to -2.27 Gt/yr, depending on the combination of gas transfer algorithms and global climatological wind speeds used. Different combinations of SST and SSS global fields resulted in changes as large as 35% on the oceans global sea-air flux. An error as small as plus or minus 0.2 in SSS translates into a plus or minus 43% deviation on the mean global CO2 flux. This result emphasizes the need for highly accurate satellite SSS observations for the development of remote sensing sea-air flux algorithms.

  11. Cloud-to-ground lightning over Mexico and adjacent oceanic regions: a preliminary climatology using the WWLLN dataset

    Directory of Open Access Journals (Sweden)

    B. Kucieńska

    2010-11-01

    Full Text Available This work constitutes the first climatological study of lightning over Mexico and adjacent oceanic areas for the period 2005–2009. Spatial and temporal distributions of cloud to ground lightning are presented and the processes that contribute to the lightning variability are analysed.

    The data are retrieved from the World Wide Lightning Location Network (WWLLN dataset. The current WWLL network includes 40 stations which cover much of the globe and detect very low frequency radiation ("spherics" associated with lightning.

    The spatial distribution of the average yearly lightning over the continental region of Mexico shows the influence of orographic forcing in producing convective clouds with high lightning activity. However, a very high number of strikes is also observed in the States of Tabasco and Campeche, which are low-lying areas. This maximum is related to the climatological maximum of precipitation for the country and it may be associated with a region of persistent low-level convergence and convection in the southern portion of the Gulf of Mexico.

    The maps of correlation between rainfall and lightning provide insight into the microphysical processes occurring within the clouds. The maritime clouds close to the coastline exhibit similar properties to continental clouds as they produce very high lightning activity.

    The seasonal cycle of lightning registered by WWLLN is consistent with the LIS/OTD dataset for the selected regions. In terms of the annual distribution of cloud-to-ground strikes, July, August and September exhibit the highest number of strikes over continental Mexico. The diurnal cycle indicates that the maximum number of strikes over the continent is observed between 6 and 9 p.m. LT.

    The surrounding oceanic regions were subdivided into four distinct sectors: Gulf of Mexico, Caribbean, Sub-tropical Pacific and Tropical Pacific. The Gulf of Mexico has the broadest seasonal

  12. Cloud-to-ground lightning over Mexico and adjacent oceanic regions. A preliminary climatology using the WWLLN dataset

    Energy Technology Data Exchange (ETDEWEB)

    Kucienska, B.; Raga, G.B. [Universidad Nacional Autonoma de Mexico (Mexico). Centro de Ciencias de la Atmosfera; Rodriguez, O. [Instituto Mexicano de Tecnologia del Agua, Morelos (Mexico)

    2010-07-01

    This work constitutes the first climatological study of lightning over Mexico and adjacent oceanic areas for the period 2005-2009. Spatial and temporal distributions of cloud to ground lightning are presented and the processes that contribute to the lightning variability are analysed. The data are retrieved from theWorldWide Lightning Location Network (WWLLN) dataset. The current WWLL network includes 40 stations which cover much of the globe and detect very low frequency radiation (''spherics'') associated with lightning. The spatial distribution of the average yearly lightning over the continental region of Mexico shows the influence of orographic forcing in producing convective clouds with high lightning activity. However, a very high number of strikes is also observed in the States of Tabasco and Campeche, which are low-lying areas. This maximum is related to the climatological maximum of precipitation for the country and it may be associated with a region of persistent low-level convergence and convection in the southern portion of the Gulf of Mexico. The maps of correlation between rainfall and lightning provide insight into the microphysical processes occurring within the clouds. The maritime clouds close to the coastline exhibit similar properties to continental clouds as they produce very high lightning activity. The seasonal cycle of lightning registered by WWLLN is consistent with the LIS/OTD dataset for the selected regions. In terms of the annual distribution of cloud-to-ground strikes, July, August and September exhibit the highest number of strikes over continental Mexico. The diurnal cycle indicates that the maximum number of strikes over the continent is observed between 6 and 9 p.m. LT. The surrounding oceanic regions were subdivided into four distinct sectors: Gulf of Mexico, Caribbean, Subtropical Pacific and Tropical Pacific. The Gulf of Mexico has the broadest seasonal distribution, since during winter lightning associated

  13. Some implications of time series analysis for describing climatologic conditions and for forecasting. An illustrative case: Veracruz, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gay, C.; Estrada, F.; Conde, C. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E:mail: feporrua@atmosfera.unam.mx

    2007-04-15

    The common practice of using 30-year sub-samples of climatological data for describing past, present and future conditions has been widely applied, in many cases without considering the properties of the time series analyzed. This paper shows that this practice can lead to an inefficient use of the information contained in the data and to an inaccurate characterization of present, and especially future, climatological conditions because parameters are time and sub-sample size dependent. Furthermore, this approach can lead to the detection of spurious changes in distribution parameters. The time series analysis of observed monthly temperature in Veracruz, Mexico, is used to illustrate the fact that these techniques permit to make a better description of the mean and variability of the series, which in turn allows (depending on the class of process) to restrain uncertainty of forecasts, and therefore provides a better estimation of present and future risk of observing values outside a given coping range. Results presented in this paper show that, although a significant trend is found in the temperatures, giving possible evidence of observed climate change in the region, there is no evidence to support changes in the variability of the series and therefore there is neither observed evidence to support that monthly temperature variability will increase (or decrease) in the future. That is, if climate change is already occurring, it has manifested itself as a change-in-the-mean of these processes and has not affected other moments of their distributions (homogeneous non-stationary processes). The Magicc-Scengen, a software useful for constructing climate change scenarios, uses 20-year sub-samples to estimate future climate variability. For comparison purposes, possible future probability density functions are constructed following two different approaches: one, using solely the Magicc-Scengen output, and another one using a combination of this information and the time

  14. Siberia snow depth climatology derived from SSM/I data using a combined dynamic and static algorithm

    Science.gov (United States)

    Grippa, M.; Mognard, N.; Le, Toan T.; Josberger, E.G.

    2004-01-01

    One of the major challenges in determining snow depth (SD) from passive microwave measurements is to take into account the spatiotemporal variations of the snow grain size. Static algorithms based on a constant snow grain size cannot provide accurate estimates of snow pack thickness, particularly over large regions where the snow pack is subjected to big spatial temperature variations. A recent dynamic algorithm that accounts for the dependence of the microwave scattering on the snow grain size has been developed to estimate snow depth from the Special Sensor Microwave/Imager (SSM/I) over the Northern Great Plains (NGP) in the US. In this paper, we develop a combined dynamic and static algorithm to estimate snow depth from 13 years of SSM/I observations over Central Siberia. This region is characterised by extremely cold surface air temperatures and by the presence of permafrost that significantly affects the ground temperature. The dynamic algorithm is implemented to take into account these effects and it yields accurate snow depths early in the winter, when thin snowpacks combine with cold air temperatures to generate rapid crystal growth. However, it is not applicable later in the winter when the grain size growth slows. Combining the dynamic algorithm to a static algorithm, with a temporally constant but spatially varying coefficient, we obtain reasonable snow depth estimates throughout the entire snow season. Validation is carried out by comparing the satellite snow depth monthly averages to monthly climatological data. We show that the location of the snow depth maxima and minima is improved when applying the combined algorithm, since its dynamic portion explicitly incorporate the thermal gradient through the snowpack. The results obtained are presented and evaluated for five different vegetation zones of Central Siberia. Comparison with in situ measurements is also shown and discussed. ?? 2004 Elsevier Inc. All rights reserved.

  15. The Global Historical Climatology Network: Long-term monthly temperature, precipitation, sea level pressure, and station pressure data

    Energy Technology Data Exchange (ETDEWEB)

    Vose, R.S. (Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center); Schmoyer, R.L. (Oak Ridge National Lab., TN (United States)); Steurer, P.M.; Peterson, T.C.; Heim, R.; Karl, T.R. (National Climatic Data Center, Asheville, NC (United States)); Eischeid, J.K. (Colorado Univ., Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences)

    1992-07-01

    Interest in global climate change has risen dramatically during the last several years. In a similar fashion, the number of data sets available to study global change has also increased. Unfortunately, these data sets have been compiled by many different organizations/researchers, making it confusing and time consuming for individual researchers to acquire the best'' data. In response to this rapid growth in the number of global data sets, the Carbon Dioxide Information Analysis Center (CDIAC) and the National Climatic Data Center (NCDC) commenced the Global Historical Climatology Network (GHCN) project. The purpose of this project is to compile an improved global base-line data set of long-term monthly mean temperature, precipitation, sea level pressure, and station pressure for a dense network. of worldwide meteorological stations. Specifically, the GHCN project seeks to consolidate the numerous preexisting national-, regional-, and global-scale data sets into a single global climate data base that can be updated, enhanced, and distributed at regular intervals. The first version of the GHCN data base was completed during the summer of 1992. It contains 6039 temperature, 7533 precipitation, 1883 sea level pressure, and 1873 station pressure stations. All stations have at least 10 years of data, 40% have more than 50 years of data, and 10% have more than 100 years of data. Spatial coverage is good over most of the globe, particularly for the United States and central Europe. In comparison to other major global data sets, dramatic improvements are evident over South America, Africa, and Asia. The GHCN data base is available as a Numeric Data Package (NDP) from CDIAC. The NDP consists of this document and two magnetic tapes that contain machine-readable data files and accompanying retrieval codes. This document describes, in detail, both the GHCN data base and the contents of the magnetic tap

  16. The Global Historical Climatology Network: Long-term monthly temperature, precipitation, sea level pressure, and station pressure data

    Energy Technology Data Exchange (ETDEWEB)

    Vose, R.S. [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center; Schmoyer, R.L. [Oak Ridge National Lab., TN (United States); Steurer, P.M.; Peterson, T.C.; Heim, R.; Karl, T.R. [National Climatic Data Center, Asheville, NC (United States); Eischeid, J.K. [Colorado Univ., Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences

    1992-07-01

    Interest in global climate change has risen dramatically during the last several years. In a similar fashion, the number of data sets available to study global change has also increased. Unfortunately, these data sets have been compiled by many different organizations/researchers, making it confusing and time consuming for individual researchers to acquire the ``best`` data. In response to this rapid growth in the number of global data sets, the Carbon Dioxide Information Analysis Center (CDIAC) and the National Climatic Data Center (NCDC) commenced the Global Historical Climatology Network (GHCN) project. The purpose of this project is to compile an improved global base-line data set of long-term monthly mean temperature, precipitation, sea level pressure, and station pressure for a dense network. of worldwide meteorological stations. Specifically, the GHCN project seeks to consolidate the numerous preexisting national-, regional-, and global-scale data sets into a single global climate data base that can be updated, enhanced, and distributed at regular intervals. The first version of the GHCN data base was completed during the summer of 1992. It contains 6039 temperature, 7533 precipitation, 1883 sea level pressure, and 1873 station pressure stations. All stations have at least 10 years of data, 40% have more than 50 years of data, and 10% have more than 100 years of data. Spatial coverage is good over most of the globe, particularly for the United States and central Europe. In comparison to other major global data sets, dramatic improvements are evident over South America, Africa, and Asia. The GHCN data base is available as a Numeric Data Package (NDP) from CDIAC. The NDP consists of this document and two magnetic tapes that contain machine-readable data files and accompanying retrieval codes. This document describes, in detail, both the GHCN data base and the contents of the magnetic tap

  17. Climatology and Biometeorology: two new topics of the State of Environment Report for Policymakers in the Florentine Area

    Science.gov (United States)

    Petralli, M.; Massetti, L.; Pozzi, R.; Orlandini, S.

    2009-09-01

    The importance of a sustainable urban planning is increasing in the last few years and it will be even more important in the future years: in fact, there is a global tendency towards an increasing population concentration in cities, strictly related to urban sprawl , as it has already been underlined by many international reports. The quality of Urban life is strongly affected by climatic conditions and at the same time urbanization is modifying local climate as, for instance, the increasing temperature and the strengthening of Urban Heat Island (UHI) effect. From 2004, the Florence Municipality with other 8 neighbour municipality, started the "Agenda21 of the Florentine Area” Project: the aim of this project was to create a network between some similar and neighbour Municipality to pursue "sustainable development" as an urbanization model capable of reconciling environmental integrity, social equity and economic efficiency. Every two years, a Report on the environment state and the sustainability of the Florentine area is provided. The main themes of the report are Air, Soil, Nature and Landscape, Economic and social issues, Energy, Waste, Electromagnetism, Water, Traffic and Good practices. For the first time in 2008 Florence Municipality decided to include biometeorological indicators in its Report. A section was dedicated to the description of Florence climate and annual trends of average air temperature and total amount of precipitation, while another section was dedicated to the impacts of extreme bio-climatic conditions on citizens' health. In addition, the report highlights how the knowledge of climate and meteorological conditions can be a cross-cutting theme, underlining the mutual influence between climate and almost all the indicators included in the report. The 2008 Florentine Report represents the first step towards the implementation of an effective tool that underlines the importance of climatological and biometeorological issues in the future

  18. Stratospheric ozone climatology and variability over a southern subtropical site: Reunion Island (21° S; 55° E

    Directory of Open Access Journals (Sweden)

    S. Godin-Beekmann

    2007-11-01

    Full Text Available The study presents the climatological characteristics of stratospheric ozone observed over Reunion Island using in-situ (ozonesonde and SAOZ and satellite (UARS-HALOE, SAGE-II and TOMS measurements. It uses co-localised ozonesondes (from September 1992 to February 2005 and SAOZ measurements (from January 1993 to December 2004, SAGE-II data from October 1984 to February 1999 (~15 years, HALOE data from January 1991 to February 2005 (~15 years, and NIMBUS/TOMS data from January 1978 to December 2004 (27 years. The satellite measurements correspond to overpasses located nearby Reunion Island (21° S; 55° E. The height profiles of ozone concentration obtained from ozonesonde (0.5–29.5 km show less bias in comparison with the HALOE and SAGE-II measurements. Though, the satellite (HALOE and SAGE-II measurements underestimate the tropospheric ozone, they are in good agreement for the heights above 15 km. The bias between the measurements and the normalized ozone profile constructed from the ozonesonde and SAGE-II satellite measurement shows that the SAGE-II measurements are more accurate than the HALOE measurements in the lower stratosphere. The monthly variation of ozone concentration derived from ozonesonde and HALOE shows a nearly annual cycle with a maximum concentration during winter/spring and minimum concentration during summer/autumn months. The time evolution of total column ozone obtained from TOMS, SAOZ and the one computed from ozonesonde and SAGE-II, exhibits similar behaviour with analogous trends as above. The TOMS variation displays a higher value of total column ozone of about 3–5 DU (10% in comparison with the SAOZ and the integrated ozone from ozonesonde and SAGE-II.

  19. Hydrographic climatology in the Gulf of St. Lawrence: its recent trends and an estuarine regime of interannual variability

    Science.gov (United States)

    Yankovsky, Alexander; Yashayaev, Igor; Frank, Alejandro

    2016-04-01

    Combining hydrographic data from the NOAA NODC World Ocean Database and the archive of the Bedford Institute of Oceanography we construct a hydrographic climatology of the Gulf of St. Lawrence (GSL) and analyze interannual to multidecadal variability of its principal water masses. Our analysis is based on the assumption that buoyancy is a primary forcing mechanism defining thermohaline fields and driving circulation in GSL, which in turn dictates the selection of representative transects. We analyze ensembles of hydrographic conditions, parameters of seasonal cycle, seasonal-to-interannual anomalies and long-term trends in each distance-depth bin of several transects orthogonal or tangential to the principal pathways of buoyancy-driven flows in GSL. In the Cabot Strait, the surface layer exhibits freshening while the bottom layer (affected by the Atlantic water influx) becomes warmer and saltier. The latter tendency can be traced along the axis of the entire Laurentian Channel and becomes even stronger further inland (e.g., off Anticosti Isl.). This enhancement in two-layer estuarine exchange flow is likely related to the freshening effect of the melting ice further north advected into the Gulf, or to the stronger freshwater discharge mixing in the Gulf. Indeed, the near-surface coastal bin off Nova Scotia occupied by the coastal buoyancy current originating from the St. Lawrence estuary does not reveal similar freshening. Interannual variability of temperature and salinity also exhibits patterns of estuarine exchange: near-bottom temperature and salinity indicative of the return flow from the Atlantic into GSL correlate with the St. Lawrence River discharge. The coastal buoyancy current responds to variations in the freshwater discharge by its expansion offshore while the salinity variations near the coast do not show a significant relationship with the discharge. Accelerating departure of hydrographic anomalies from their record-mean trends is observed over the

  20. Climatology of new particle formation events in the subtropical North Atlantic free troposphere at Izaña GAW observatory

    Science.gov (United States)

    García, M. I.; Rodríguez, S.; González, Y.; García, R. D.

    2013-09-01

    A climatology of new particle formation (NPF) events in the subtropical North Atlantic free troposphere is presented. A four year data set (June 2008-June 2012), which includes number size distributions (10-600 nm), reactive gases (SO2, NOx, and O3), several components of solar radiation and meteorological parameters, measured at Izaña Global Atmospheric Watch observatory (2400 m above sea level; Tenerife, Canary Islands) was analysed. On average, NPF occurred during 30% of the days,the mean values of the formation and growth rates during the study period were 0.49 cm-3 s-1 and 0.42 nm h-1, correspondingly. There is a clearly marked NPF season (May to August), when these events account for 50 to 60% of the days/month. Monthly mean values of the formation and growth rates exhibit higher values during this season (0.50-0.95 cm-3 s-1 and 0.48-0.58 nm h-1, respectively) than during other periods. The two steps (formation and growth) of the NPF process mostly occur under the prevailing northern winds typical of this region. Sulphur dioxide and UV radiation show higher levels during NPF events than in other type of episodes. The presence of Saharan dust in the free troposphere is associated with a decrease in the formation rates of new particles. In the analysis of the year-to-year variability, mean sulphur dioxide concentration (within the range 60-300 ppt) was the parameter that exhibited the highest correlation with the frequency of NPF episodes. The availability of this trace gas (i.e. their oxidation products) seems also to have a influence on the duration of the events, number of formed nucleation particles, formation rates and growth rates. We identified a set of NPF events in which two nucleation modes (that may evolve at different rates) occur simultaneously and for which further investigations are necessary.

  1. Adjustment of the thermal component of two tourism climatological assessment tools using thermal perception and preference surveys from Hungary

    Science.gov (United States)

    Kovács, Attila; Unger, János; Gál, Csilla V.; Kántor, Noémi

    2015-05-01

    This study introduces new methodological concepts for integrating seasonal subjective thermal assessment patterns of people into the thermal components of two tourism climatological evaluation tools: the Tourism Climatic Index (TCI) and the Climate-Tourism/Transfer-Information-Scheme (CTIS). In the case of the TCI, we replaced the air temperature and relative humidity as the basis of the initial rating system with the physiologically equivalent temperature (PET)—a complex human biometeorological index. This modification improves the TCI's potential to evaluate the thermal aspects of climate. The major accomplishments of this study are (a) the development of a new, PET-based rating system and its integration into the thermal sub-indices of the TCI and (b) the regionalization of the thermal components of CTIS to reflect both the thermal sensation and preference patterns of people. A 2-year-long (2011-2012) thermal comfort survey conducted in Szeged, Hungary, from spring to autumn was utilized to demonstrate the implementation of the introduced concepts. We found considerable differences between the thermal perception and preference patterns of Hungarians, with additional variations across the evaluated seasons. This paper describes the proposed methodology for the integration of the new seasonal, perception-based, and preference-based PET rating systems into the TCI, and presents the incorporation of new PET thresholds into the CTIS. In order to demonstrate the utility of the modified evaluation tools, we performed case study climate analyses for three Hungarian tourist destinations. The additional adjustments introduced during the course of those analyses include the reduction of TCI's temporal resolution to 10-day intervals and the exclusion of nocturnal and winter periods from the investigation.

  2. West African equatorial ionospheric parameters climatology based on Ouagadougou ionosonde station data from June 1966 to February 1998

    Directory of Open Access Journals (Sweden)

    F. Ouattara

    2009-06-01

    Full Text Available This study is the first which gives the climatology of West African equatorial ionosphere by using Ouagadougou station through three solar cycles. It has permitted to show the complete morphology of ionosphere parameters by analyzing yearly variation, solar cycle and geomagnetic activity, seasonal evolution and diurnal development. This work shows that almost all ionospheric parameters have 11-year solar cycle evolution. Seasonal variation shows that only foF2 exhibits annual, winter and semiannual anomaly. foF2 seasonal variation has permitted us to identify and characterize solar events effects on F2 layer in this area. In fact (1 during quiet geomagnetic condition foF2 presents winter and semiannual anomalies asymmetric peaks in March/April and October. (2 The absence of winter anomaly and the presence of equinoctial peaks are the most visible effects of fluctuating activity in foF2 seasonal time profiles. (3 Solar wind shock activity does not modify the profile of foF2 but increases ionization. (4 The absence of asymmetry peaks, the location of the peaks in March and October and the increase of ionization characterize recurrent storm activity. F1 layers shows increasing trend from cycle 20 to cycle 21. Moreover, E layer parameters seasonal variations exhibit complex structure. It seems impossible to detect fluctuating activity effect in E layer parameters seasonal variations but shock activity and wind stream activity act to decrease E layer ionization. It can be seen from Es layer parameters seasonal variations that wind stream activity effect is fairly independent of solar cycle. E and Es layers critical frequencies and virtual heights diurnal variations let us see the effects of the greenhouse gases in these layers.

  3. Adjustment of the thermal component of two tourism climatological assessment tools using thermal perception and preference surveys from Hungary

    Science.gov (United States)

    Kovács, Attila; Unger, János; Gál, Csilla V.; Kántor, Noémi

    2016-07-01

    This study introduces new methodological concepts for integrating seasonal subjective thermal assessment patterns of people into the thermal components of two tourism climatological evaluation tools: the Tourism Climatic Index (TCI) and the Climate-Tourism/Transfer-Information-Scheme (CTIS). In the case of the TCI, we replaced the air temperature and relative humidity as the basis of the initial rating system with the physiologically equivalent temperature (PET)—a complex human biometeorological index. This modification improves the TCI's potential to evaluate the thermal aspects of climate. The major accomplishments of this study are (a) the development of a new, PET-based rating system and its integration into the thermal sub-indices of the TCI and (b) the regionalization of the thermal components of CTIS to reflect both the thermal sensation and preference patterns of people. A 2-year-long (2011-2012) thermal comfort survey conducted in Szeged, Hungary, from spring to autumn was utilized to demonstrate the implementation of the introduced concepts. We found considerable differences between the thermal perception and preference patterns of Hungarians, with additional variations across the evaluated seasons. This paper describes the proposed methodology for the integration of the new seasonal, perception-based, and preference-based PET rating systems into the TCI, and presents the incorporation of new PET thresholds into the CTIS. In order to demonstrate the utility of the modified evaluation tools, we performed case study climate analyses for three Hungarian tourist destinations. The additional adjustments introduced during the course of those analyses include the reduction of TCI's temporal resolution to 10-day intervals and the exclusion of nocturnal and winter periods from the investigation.

  4. State Climatology Books

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Substation history publications by state. Includes station metadata such as station name and location changes, observer names and changes, alternate station names....

  5. Local Climatological Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Publication containing summaries from major U.S. airport stations that include a daily account of temperature extremes, degree days, hourly and daily precipitation...

  6. OW COADS Climatology

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — COADS (Comprehensive Ocean-Atmosphere Data Set) is a ocean-atmosphere data set generated by means of in-situ (ship) measurements and reports from around the world's...

  7. Climatological Data Publication

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Major US airport weather stations monthly and annual publication containing station daily maximum and minimum temperatures, precipitation amounts, and monthly...

  8. First Evaluation of the Climatological Calibration Algorithm in the Real-time TMPA Precipitation Estimates over Two Basins at High and Low Latitudes

    Science.gov (United States)

    Yong, Bin; Ren, Liliang; Hong, Yang; Gourley, Jonathan; Tian, Yudong; Huffman, George J.; Chen, Xi; Wang, Weiguang; Wen, Yixin

    2013-01-01

    The TRMM Multi-satellite Precipitation Analysis (TMPA) system underwent a crucial upgrade in early 2009 to include a climatological calibration algorithm (CCA) to its realtime product 3B42RT, and this algorithm will continue to be applied in the future Global Precipitation Measurement era constellation precipitation products. In this study, efforts are focused on the comparison and validation of the Version 6 3B42RT estimates before and after the climatological calibration is applied. The evaluation is accomplished using independent rain gauge networks located within the high-latitude Laohahe basin and the low-latitude Mishui basin, both in China. The analyses indicate the CCA can effectively reduce the systematic errors over the low-latitude Mishui basin but misrepresent the intensity distribution pattern of medium-high rain rates. This behavior could adversely affect TMPA's hydrological applications, especially for extreme events (e.g., floods and landslides). Results also show that the CCA tends to perform slightly worse, in particular, during summer and winter, over the high-latitude Laohahe basin. This is possibly due to the simplified calibration-processing scheme in the CCA that directly applies the climatological calibrators developed within 40 degrees latitude to the latitude belts of 40 degrees N-50 degrees N. Caution should therefore be exercised when using the calibrated 3B42RT for heavy rainfall-related flood forecasting (or landslide warning) over high-latitude regions, as the employment of the smooth-fill scheme in the CCA bias correction could homogenize the varying rainstorm characteristics. Finally, this study highlights that accurate detection and estimation of snow at high latitudes is still a challenging task for the future development of satellite precipitation retrievals.

  9. Climatological classification of five sectors in the Iberian Peninsula using columnar (AOD, α) and surface (PM10, PM2.5) aerosol data supported by air mass apportioning

    Science.gov (United States)

    Cachorro, Victoria; Mateos, David; Toledano, Carlos; Burgos, Maria A.; Bennouna, Yasmine; Torres, Benjamín; Fuertes, David; González, Ramiro; Guirado, Carmen; Román, Roberto; Velasco-Merino, Cristian; Marcos, Alberto; Calle, Abel; de Frutos, Angel M.

    2015-04-01

    The study of atmospheric aerosol over the Iberian Peninsula (IP) under a climatologic perspective is an interesting and meaningful aim due to the wide variety of conditions (geographical position, air masses, topography, among others) which cause a complex role of the distribution of aerosol properties. In the deeply investigation on the annual cycle and time evolution of the particulate matter lower than 10 µm (PM10, surface) and aerosol optical depth (AOD, columnar) in a large number of sites covering the period 2000-2013, five sectors can be distinguished in the IP. Both set of data belong to EMEP and AERONET networks respectively, as representative of aerosol air quality and climate studies, are complementary elements for a global aerosol research. The prevalence of fine-coarse particles is also analyzed over each sector. Seasonal bimodality of the PM10 annual cycle with a strong North-South gradient is observed in most sites, but this is only reported in the AOD climatology for the southern IP. The northern coast is clearly governed by the Atlantic Ocean influence, while the northeastern area is modulated by the Mediterranean Sea. The southern area, very close to the African continent, presents a large influence of desert dust intrusions. However, the southern Atlantic and Mediterranean coast present discrepancies and two sectors have been defined in this area. Finally, the center of the Peninsula is a mix of conditions, with north-south and east-west gradients of different magnitude. Overall, there is a relationship between PM10 and AOD with a proportional factor varying from 20 to 90, depending on the sector. The particular characteristic of PM10-AOD annual cycle of each geographical sector can be understood by the different climatology of the air mass origins observed at 500 and 1500 m (a.s.l.) and its apportioning to PM10 and AOD, respectively.

  10. A 6-year global climatology of occurrence of upper-tropospheric ice supersaturation inferred from the Atmospheric Infrared Sounder after synergetic calibration with MOZAIC

    Directory of Open Access Journals (Sweden)

    N. Lamquin

    2011-04-01

    Full Text Available Ice supersaturation in the upper troposphere is a complex and important issue for the understanding of cirrus cloud formation. Infrared sounders have the ability to provide cloud properties and atmospheric profiles of temperature and humidity. On the other hand, they suffer from coarse vertical resolution, especially in the upper troposphere and therefore are unable to detect shallow ice supersaturated layers. We have used data from the Measurements of OZone and water vapour by AIrbus in-service airCraft experiment (MOZAIC in combination with Atmospheric InfraRed Sounder (AIRS relative humidity measurements and cloud properties to develop a calibration method for an estimation of occurrence frequencies of ice supersaturation. This method first determines the occurrence probability of ice supersaturation, detected by MOZAIC, as a function of the relative humidity determined by AIRS. The occurrence probability function is then applied to AIRS data, independently of the MOZAIC data, to provide a global climatology of upper-tropospheric ice supersaturation occurrence. Our climatology is then related to high cloud occurrence from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP and compared to ice supersaturation occurrence statistics from MOZAIC alone. Finally it is compared to model climatologies of ice supersaturation from the Integrated Forecast System (IFS of the European Centre for Medium-Range Weather Forecasts (ECMWF and from the European Centre HAmburg Model (ECHAM. All the comparisons show good agreements when considering the limitations of each instrument and model. This study highlights the benefits of multi-instrumental synergies for the investigation of upper tropospheric ice supersaturation.

  11. Understanding climatological, instantaneous and reference VTEC maps, its variability, its relation to STEC and its assimilation by VTEC models

    Science.gov (United States)

    Orus, R.; Prieto-Cerdeira, R.

    2012-12-01

    As the next Solar Maximum peak is approaching, forecasted for the late 2013, it is a good opportunity to study the ionospheric behaviour in such conditions and how this behaviour can be estimated and corrected by existing climatological models - e.g.. NeQuick, International Reference Ionosphere (IRI)- , as well as, GNSS driven models, such as Klobuchar, NeQuick Galileo, SBAS MOPS (EGNOS and WAAS corrections) and Near Real Time Global Ionospheric Maps (GIM) or regional Maps computed by different institutions. In this framework, technology advances allow to increase the computational and radio frequency channels capabilities of low-cost receivers embedded in handheld devices (such mobile phones, pads, trekking clocks, photo-cameras, etc). This may enable the active use of received ionospheric data or correction parameters from different data sources. The study is centred in understanding the ionosphere but focusing on its impact on the position error for low-cost single-frequency receivers. This study tests optimal ways to take advantage of a big amount of Real or Near Real Time ionospheric information and the way to combine various corrections in order to reach a better navigation solution. In this context, the use of real time estimation vTEC data coming from EGNOS or WAAS or near real time GIMs are used to feed the standard GPS single-frequency ionospheric correction models (Klobuchar) and get enhanced Ionospheric corrections with minor changes on the navigation software. This is done by using a Taylor expansion over the 8 coefficients send by GPS. Moreover, the same datasets are used to assimilate it in NeQuick, for broadcast coefficients, as well as, for grid assimilation. As a side product, electron density profiles in Near Real Time could be estimated with data assimilated from different ionospheric sources. Finally, the ionospheric delay estimation for multi-constellation receivers could take benefit from a common and more accurate ionospheric model being

  12. Validation of Long-Term Global Aerosol Climatology Project Optical Thickness Retrievals Using AERONET and MODIS Data

    Science.gov (United States)

    Geogdzhayev, Igor V.; Mishchenko, Michael I.

    2015-01-01

    A comprehensive set of monthly mean aerosol optical thickness (AOT) data from coastal and island AErosol RObotic NETwork (AERONET) stations is used to evaluate Global Aerosol Climatology Project (GACP) retrievals for the period 1995-2009 during which contemporaneous GACP and AERONET data were available. To put the GACP performance in broader perspective, we also compare AERONET and MODerate resolution Imaging Spectroradiometer (MODIS) Aqua level-2 data for 2003-2009 using the same methodology. We find that a large mismatch in geographic coverage exists between the satellite and ground-based datasets, with very limited AERONET coverage of open-ocean areas. This is especially true of GACP because of the smaller number of AERONET stations at the early stages of the network development. Monthly mean AOTs from the two over-the-ocean satellite datasets are well-correlated with the ground-based values, the correlation coefficients being 0.81-0.85 for GACP and 0.74-0.79 for MODIS. Regression analyses demonstrate that the GACP mean AOTs are approximately 17%-27% lower than the AERONET values on average, while the MODIS mean AOTs are 5%-25% higher. The regression coefficients are highly dependent on the weighting assumptions (e.g., on the measure of aerosol variability) as well as on the set of AERONET stations used for comparison. Comparison of over-the-land and over-the-ocean MODIS monthly mean AOTs in the vicinity of coastal AERONET stations reveals a significant bias. This may indicate that aerosol amounts in coastal locations can differ significantly from those in adjacent open-ocean areas. Furthermore, the color of coastal waters and peculiarities of coastline meteorological conditions may introduce biases in the GACP AOT retrievals. We conclude that the GACP and MODIS over-the-ocean retrieval algorithms show similar ranges of discrepancy when compared to available coastal and island AERONET stations. The factors mentioned above may limit the performance of the

  13. Climatology of new particle formation events in the subtropical North Atlantic free troposphere at Izaña GAW observatory

    Directory of Open Access Journals (Sweden)

    M. I. García

    2013-09-01

    Full Text Available A climatology of new particle formation (NPF events in the subtropical North Atlantic free troposphere is presented. A four year data set (June 2008–June 2012, which includes number size distributions (10–600 nm, reactive gases (SO2, NOx, and O3, several components of solar radiation and meteorological parameters, measured at Izaña Global Atmospheric Watch observatory (2400 m above sea level; Tenerife, Canary Islands was analysed. On average, NPF occurred during 30% of the days,the mean values of the formation and growth rates during the study period were 0.49 cm−3 s−1 and 0.42 nm h−1, correspondingly. There is a clearly marked NPF season (May to August, when these events account for 50 to 60% of the days/month. Monthly mean values of the formation and growth rates exhibit higher values during this season (0.50–0.95 cm−3 s−1 and 0.48–0.58 nm h−1, respectively than during other periods. The two steps (formation and growth of the NPF process mostly occur under the prevailing northern winds typical of this region. Sulphur dioxide and UV radiation show higher levels during NPF events than in other type of episodes. The presence of Saharan dust in the free troposphere is associated with a decrease in the formation rates of new particles. In the analysis of the year-to-year variability, mean sulphur dioxide concentration (within the range 60–300 ppt was the parameter that exhibited the highest correlation with the frequency of NPF episodes. The availability of this trace gas (i.e. their oxidation products seems also to have a influence on the duration of the events, number of formed nucleation particles, formation rates and growth rates. We identified a set of NPF events in which two nucleation modes (that may evolve at different rates occur simultaneously and for which further investigations are necessary.

  14. Climatology of new particle formation at Izaña mountain GAW observatory in the subtropical North Atlantic

    Science.gov (United States)

    García, M. I.; Rodríguez, S.; González, Y.; García, R. D.

    2014-04-01

    A climatology of new particle formation (NPF) events at high altitude in the subtropical North Atlantic is presented. A 4-year data set (June 2008-June 2012), which includes number size distributions (10-600 nm), reactive gases (SO2, NOx, and O3), several components of solar radiation and meteorological parameters, measured at Izaña Global Atmosphere Watch (GAW) observatory (2373 m above sea level; Tenerife, Canary Islands) was analysed. NPF is associated with the transport of gaseous precursors from the boundary layer by orographic buoyant upward flows that perturb the low free troposphere during daytime. On average, 30% of the days contained an NPF event. Mean values of the formation and growth rates during the study period were 0.46 cm-3 s-1 and 0.42 nm h-1, correspondingly. There is a clearly marked NPF season (May-August), when these events account for 50-60% of the days per month. Monthly mean values of the formation and growth rates exhibit higher values in this season, 0.49-0.92 cm-3 s-1 and 0.48-0.58 nm h-1, respectively. During NPF events, SO2, UV radiation and upslope winds showed higher values than during non-events. The overall data set indicates that SO2 plays a key role as precursor, although other species seem to contribute during some periods. Condensation of sulfuric acid vapour accounts for most of the measured particle growth during most of the year (~70%), except for some periods. In May, the highest mean growth rates (~0.6 nm h-1) and the lowest contribution of sulfuric acid (~13%) were measured, suggesting a significant involvement of other condensing vapours. The SO2 availability seems also to be the most influencing parameter in the year-to-year variability in the frequency of NPF events. The condensation sink showed similar features to other mountain sites, showing high values during NPF events. Summertime observations, when Izaña is within the Saharan Air Layer, suggest that dust particles may play a significant role acting as

  15. An approach to integrate spatial and climatological data as support to drought monitoring and agricultural management problems in South Sudan

    Science.gov (United States)

    Bonetto, Sabrina; Facello, Anna; Camaro, Walther; Isotta Cristofori, Elena; Demarchi, Alessandro

    2016-04-01

    humanitarian emergencies, the precipitation is used to monitoring potential drought events in the critical periods of the year. The methods employed and integrated different satellite data (Landsat and NASA-TRMM) in order to generate a proper database for the analysis of the seasonal movements according to climatological variations. Preliminary results will be presented and discussed.

  16. Solving the scale-conflict between crop models and the climate information by a catchment-specific geospatial climatology

    Science.gov (United States)

    Yun, J. I.; Kim, J.; Kim, S.; Kim, D.

    2012-12-01

    The spatial resolution of local agrometeorological service for farming activities often exceeds the current scales of weather and climate information. When crop models are applied to regional scales, the same problem occurs especially in complex terrain where the coarse meteorological inputs can never represent the underlying land attributes. To supplement the insufficient spatial resolution of official weather and climate information, we suggest a catchment-specific climate mapping scheme based on recently developed techniques in geospatial climatology. Given a single value for a catchment from the nearest weather office, a daily minimum temperature surface at a 30m resolution across the catchment can be produced by the cold air drainage and thermal belt effect embedded in this scheme. Daily maximum temperature can be estimated at the same resolution by applying the solar irradiance effect on sloping surfaces. The PRISM model was modified to accommodate the micro topography effect within a catchment to predict local rainfall at a 270m grid spacing. We applied this scheme to each of the 840 official watersheds of South Korea and 855 watersheds temporarily prepared for North Korea to produce monthly average maps for daily maximum and minimum temperature, solar radiation, and precipitation, each representing a decadal average year for the 9 future periods (2011-2100) as well as the 4 past periods (1971-2010). These primary products were further processed into the secondary products including extremes, sums, and probabilities of climatic events relevant to farming activities at a given grid cell. In addition, the monthly data were used in a stochastic weather generator to produce multiple sets of daily weather data for each decade. Any agronomic models could be run by the generated daily data to project the site-specific growth and development of crops with inter-annual variation. The fine resolution of the grid cell enables pin pointing real-world farms or orchards

  17. Climatology of low latitude ionosphere under effect of varying solar flux during solar cycle 23 and 24

    Science.gov (United States)

    Dashora, Nirvikar; Suresh, Sunanda

    2016-07-01

    The characteristics of quiet time equatorial and low latitude total electron content (TEC) over the Indian sector using GIM data (1998-2014) is obtained. For the first time the analysis is carried filtering out the solar flare and storm effects and time series of quiet time VTEC data from three locations namely dip equator and two low latitude conjugate locations in Indian sector are obtained. It is well known that a complex interplay among drivers of equatorial electrodynamics like Solar flux, dynamo electric field and meridional winds determine the daytime ionization and distribution in equatorial ionization anomaly zone. In this study, we have critically examined the role of varying solar flux and response of low latitude ionosphere with new and standardized definitions. The results are examined and interpreted in the context of large number of previous studies. The newly found features from this study are as follows. Marked difference in nature of equinoctial asymmetry is noted between solar cycle 23 and 24. Long absence of winter anomaly both during low and high solar activity (HSA) in LL (low latitude) regions is found. Climatology of the diurnal cycle is provided in four categories using new criteria for demarcation of solar activity levels. Highest correlation (~77%) between GIM ionospheric electron content (IEC) and PI (solar EUV proxy index) is noted over equator in contrast to previous studies. The minimum positive contribution of PI in variation of IEC requires minimum of 2 years of data and if more than 7-8 years of data is used, it saturates. RMS (root mean square) width of PI can be used to define the HSA. Strong QBO (quasi biennial oscillations) in IEC is noted in tune with the one in PI over both the LL location but QBO remains surprisingly subdued over equator. The semi-annual oscillations in GIM-IEC are found to be stronger at all locations during high solar activity and weaker between 2005 and 2011, whereas, the annual oscillations are found to

  18. Low latitude ionospheric scintillation and zonal plasma irregularity drifts climatology around the equatorial anomaly crest over Kenya

    Science.gov (United States)

    Olwendo, O. J.; Baki, P.; Cilliers, P. J.; Doherty, P.; Radicella, S.

    2016-02-01

    In this study we have used a VHF and GPS-SCINDA receiver located at Nairobi (36.8°E, 1.3°S, dip -24.1°) in Kenya to investigate the climatology of ionospheric L-band scintillation occurrences for the period 2009 to 2012; and seasonal variation of the zonal plasma drift irregularities derived from a VHF receiver for the period 2011. The annual and diurnal variations of L-band scintillation indicate occurrence at post sunset hours and peaks in the equinoctial months. However VHF scintillation occurs at all seasons around the year and is characterized by longer duration of activity and a slow fading that continues till early morning hours unlike in the L-band where they cease after midnight hours. A directional analysis has shown that the spatial distribution of scintillation events is mainly on the Southern and Western part of the sky over Nairobi station closer to the edges of the crest of the Equatorial Ionization Anomaly