Hanford Site Climatological Data Summary 1999 with Historical Data

International Nuclear Information System (INIS)

Hoitink, Dana J; Burk, Kenneth W; Ramsdell, Jim V

2000-01-01

This document presents the climatological data measured at the Hanford Site for calendar year 1999. The information contained includes updated historical climatologies for temperature, precipitation, normal and extreme values of temperature and precipitation and other meteorological parameters

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

4 km NODC/RSMAS AVHRR Pathfinder Cloud Screened Version 5.0 Monthly Climatologies (1985-2006) (NODC Accession 0110657)

Data.gov (United States)

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

Gulf of Mexico Regional Climatology (NCEI Accession 0123320)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Gulf of Mexico Regional Climatology is a set of objectively analyzed climatological fields of temperature, salinity, oxygen, phosphate, silicate, and nitrate at...

New dynamic NNORSY ozone profile climatology

Science.gov (United States)

Kaifel, A. K.; Felder, M.; Declercq, C.; Lambert, J.-C.

2012-01-01

Climatological ozone profile data are widely used as a-priori information for total ozone using DOAS type retrievals as well as for ozone profile retrieval using optimal estimation, for data assimilation or evaluation of 3-D chemistry-transport models and a lot of other applications in atmospheric sciences and remote sensing. For most applications it is important that the climatology represents not only long term mean values but also the links between ozone and dynamic input parameters. These dynamic input parameters should be easily accessible from auxiliary datasets or easily measureable, and obviously should have a high correlation with ozone. For ozone profile these parameters are mainly total ozone column and temperature profile data. This was the outcome of a user consultation carried out in the framework of developing a new, dynamic ozone profile climatology. The new ozone profile climatology is based on the Neural Network Ozone Retrieval System (NNORSY) widely used for ozone profile retrieval from UV and IR satellite sounder data. NNORSY allows implicit modelling of any non-linear correspondence between input parameters (predictors) and ozone profile target vector. This paper presents the approach, setup and validation of a new family of ozone profile climatologies with static as well as dynamic input parameters (total ozone and temperature profile). The neural network training relies on ozone profile measurement data of well known quality provided by ground based (ozonesondes) and satellite based (SAGE II, HALOE, and POAM-III) measurements over the years 1995-2007. In total, four different combinations (modes) for input parameters (date, geolocation, total ozone column and temperature profile) are available. The geophysical validation spans from pole to pole using independent ozonesonde, lidar and satellite data (ACE-FTS, AURA-MLS) for individual and time series comparisons as well as for analysing the vertical and meridian structure of different modes of

On the semi-diagnostic computation of climatological circulation in the western tropical Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Shaji, C.; Rao, A.D.; Dube, S.K.; Bahulayan, N.

and internal density field on the dynamical balance of circulation in the western tropical Indian Ocean is explained. The climatological temperature and salinity data used to drive the model is found to be hydrodynamically adjusted with surface wind, flow field...

OMI/Aura Surface Reflectance Climatology Level 3 Global 0.5deg Lat/Lon Grid V003

Data.gov (United States)

National Aeronautics and Space Administration — The OMI Earth Surface Reflectance Climatology product, OMLER (Global 0.5deg Lat/Lon grid) which is based on Version 003 Level-1B top of atmosphere upwelling radiance...

Sensitive study of the climatological SST by using ATSR global SST data sets

Science.gov (United States)

Xue, Yong; Lawrence, Sean P.; Llewellyn-Jones, David T.

1995-12-01

Climatological sea surface temperature (SST) is an initial step for global climate processing monitoring. A comparison has been made by using Oberhuber's SST data set and two years monthly averaged SST from ATSR thermal band data to force the OGCM. In the eastern Pacific Ocean, these make only a small difference to model SST. In the western Pacific Ocean, the use of Oberhuber's data set gives higher climatological SST than that using ATSR data. The SSTs were also simulated for 1992 using climatological SSTs from two years monthly averaged ATSR data and Oberhuber data. The forcing with SST from ATSR data was found to give better SST simulation than that from Oberhuber's data. Our study has confirmed that ATSR can provide accurate monthly averaged global SST for global climate processing monitoring.

Multi-satellite climatologies of fundamental atmospheric variables from Radio Occulation and their validation

International Nuclear Information System (INIS)

Pirscher, B.

2010-01-01

Monitoring of global climate change requires high quality observations not only on the Earths surface but also in the free atmosphere. Global Positioning System (GPS) Radio Occultation (RO) observations are known to have the potential to deliver very accurate, precise, and long-term stable measurements between about 8 km and 30 km altitude.This thesis investigates the suitability of RO observations to serve as climate benchmark record by validating the consistency of RO data provided by different satellites. The main focus lies on systematic differences of RO climatologies, originating from different data processing, data quality, spatio-temporal sampling, and particular orbit characteristics. Data of six RO satellite missions (including one multi-satellite constellation) are analyzed. Largest disagreements of RO climatologies are observed when comparing data provided by different processing centers. Mean absolute temperature differences between 8 km and 30 km altitude amount to 0.5 K, while climate time series of temperature changes agree much closer.Utilizing RO data from the same data center and considering space-temporal sampling yields remarkable consistency of temperature climatologies with mean differences being smaller than 0.1 K. Disagreements are found to be largest at 35 km, where they exceed 0.2 K. This results from different data quality and its utilization within the processing scheme. Climatologies, which are derived from data with the same quality agree to within 0.02 K also at high altitudes. The measurements local time, which depends on the satellites orbit, has a minor but clearly understandable influence on differences in RO climatologies. The results underline the utility of RO data for long-term monitoring of the global climate. (author) [de

Climatology and trends of mesospheric (58-90) temperatures based upon 1982-1986 SME limb scattering profiles

Science.gov (United States)

Clancy, R. Todd; Rusch, David W.

1989-01-01

Atmospheric temperature profiles for the altitude range 58-90 km were calculated using data on global UV limb radiances from the SME satellite. The major elements of this climatology include a high vertical resolution (about 4 km) and the coverage of the 70-90 km altitude region. The analysis of this extensive data set provides a global definition of mesospheric-lower thermospheric temperature trends over the 1982-1986 period. The observations suggest a pattern of 1-2 K/year decreases in temperatures at 80-90-km altitudes accompanied by 0.5-1.5 K/year increases in temperatures at 65-80-km altitudes.

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,...

Ground surface temperature and continental heat gain: uncertainties from underground

International Nuclear Information System (INIS)

Beltrami, Hugo; Matharoo, Gurpreet S; Smerdon, Jason E

2015-01-01

Temperature changes at the Earth's surface propagate and are recorded underground as perturbations to the equilibrium thermal regime associated with the heat flow from the Earth's interior. Borehole climatology is concerned with the analysis and interpretation of these downward propagating subsurface temperature anomalies in terms of surface climate. Proper determination of the steady-state geothermal regime is therefore crucial because it is the reference against which climate-induced subsurface temperature anomalies are estimated. Here, we examine the effects of data noise on the determination of the steady-state geothermal regime of the subsurface and the subsequent impact on estimates of ground surface temperature (GST) history and heat gain. We carry out a series of Monte Carlo experiments using 1000 Gaussian noise realizations and depth sections of 100 and 200 m as for steady-state estimates depth intervals, as well as a range of data sampling intervals from 10 m to 0.02 m. Results indicate that typical uncertainties for 50 year averages are on the order of ±0.02 K for the most recent 100 year period. These uncertainties grow with decreasing sampling intervals, reaching about ±0.1 K for a 10 m sampling interval under identical conditions and target period. Uncertainties increase for progressively older periods, reaching ±0.3 K at 500 years before present for a 10 m sampling interval. The uncertainties in reconstructed GST histories for the Northern Hemisphere for the most recent 50 year period can reach a maximum of ±0.5 K in some areas. We suggest that continuous logging should be the preferred approach when measuring geothermal data for climate reconstructions, and that for those using the International Heat Flow Commission database for borehole climatology, the steady-state thermal conditions should be estimated from boreholes as deep as possible and using a large fitting depth range (∼100 m). (letter)

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.

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).

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

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Please note, GHCN-Monthly provides climatological observations for four elements; monthly mean maximum temperature, minimum temperature, mean temperature, and...

A satellite-based climatology (1989-2012) of lake surface water temperature from AVHRR 1-km for Central European water bodies

Science.gov (United States)

Riffler, Michael; Wunderle, Stefan

2013-04-01

The temperature of lakes is an important parameter for lake ecosystems influencing the speed of physio-chemical reactions, the concentration of dissolved gazes (e.g. oxygen), and vertical mixing. Even small temperature changes might have irreversible effects on the lacustrine system due to the high specific heat capacity of water. These effects could alter the quality of lake water depending on parameters like lake size and volume. Numerous studies mention lake water temperature as an indicator of climate change and in the Global Climate Observing System (GCOS) requirements it is listed as an essential climate variable. In contrast to in situ observations, satellite imagery offers the possibility to derive spatial patterns of lake surface water temperature (LSWT) and their variability. Moreover, although for some European lakes long in situ time series are available, the temperatures of many lakes are not measured or only on a non-regular basis making these observations insufficient for climate monitoring. However, only few satellite sensors offer the possibility to analyze time series which cover more than 20 years. The Advanced Very High Resolution Radiometer (AVHRR) is among these and has been flown on the National Oceanic and Atmospheric Administration (NOAA) Polar Operational Environmental Satellites (POES) and on the Meteorological Operational Satellites (MetOp) from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) as a heritage instrument for almost 35 years. It will be carried on for at least ten more years finally offering a unique opportunity for satellite-based climate studies. Herein we present the results from a study initiated by the Swiss GCOS office to generate a satellite-based LSWT climatology for the pre-alpine water bodies in Switzerland. It relies on the extensive AVHRR 1-km data record (1985-2012) of the Remote Sensing Research Group at the University of Bern (RSGB) and has been derived from the AVHRR/2

Climatological determinants of woody cover in Africa.

Science.gov (United States)

Good, Stephen P; Caylor, Kelly K

2011-03-22

Determining the factors that influence the distribution of woody vegetation cover and resolving the sensitivity of woody vegetation cover to shifts in environmental forcing are critical steps necessary to predict continental-scale responses of dryland ecosystems to climate change. We use a 6-year satellite data record of fractional woody vegetation cover and an 11-year daily precipitation record to investigate the climatological controls on woody vegetation cover across the African continent. We find that-as opposed to a relationship with only mean annual rainfall-the upper limit of fractional woody vegetation cover is strongly influenced by both the quantity and intensity of rainfall events. Using a set of statistics derived from the seasonal distribution of rainfall, we show that areas with similar seasonal rainfall totals have higher fractional woody cover if the local rainfall climatology consists of frequent, less intense precipitation events. Based on these observations, we develop a generalized response surface between rainfall climatology and maximum woody vegetation cover across the African continent. The normalized local gradient of this response surface is used as an estimator of ecosystem vegetation sensitivity to climatological variation. A comparison between predicted climate sensitivity patterns and observed shifts in both rainfall and vegetation during 2009 reveals both the importance of rainfall climatology in governing how ecosystems respond to interannual fluctuations in climate and the utility of our framework as a means to forecast continental-scale patterns of vegetation shifts in response to future climate change.

LAND SURFACE TEMPERATURES ESTIMATED ON GROUNDOBSERVED DATA AND SATELLITE IMAGES, DURING THE VEGETATION PERIOD IN THE OLTENIA PLAIN

Directory of Open Access Journals (Sweden)

ONŢEL IRINA

2015-03-01

Full Text Available The purpose of this study is to analyze the land surface temperatures by using climatological and remote sensing data during the vegetation period in the Oltenia Plain. The data used in this study refer both to climatological data (namely monthly and seasonal air and soil temperatures, and to remote sensing data delivered by MODIS Land Surface Temperature (LST, with a spatial resolution of 1 km. The analyzed period spans from 2000 to 2013 and the vegetation period considered is April-September. As main results, there were observed four years with high temperatures, namely 2000 (20.4oC-air T, 24.6oC soil T, and 26oC LST, 2003 (20.2oC air T, 23.9oC soil T and 24.5oC LST, 2007 (20.5oC air T, 24.3oC soil T and 25oC LST and 2012 (21.3oC air T, 25.7oC soil T and 26.5oC LST. The correlations between air temperature, soil temperature and LST were statisticaly significant. The diference between air temperature and soil temperature values ranked within 3-4oC, while the difference between soil temperature and land surface temperature obtained from MODIS images was about 0.8oC. Spatially, the highest temperatures were recorded on the Leu-Rotunda Field, the Caracal Plain and the Nedeia Field, and pretty high variations of observed temperatures seemed to depend on vegetation cover. The MODIS images represent one of the most important types of satellite data available for free, which can be successfully used in determining the climatic parameters and can help to predict the changes in plant activity, due to weather phenomena.

4 km NODC/RSMAS AVHRR Pathfinder Version 5.0 and 5.1 Monthly Harmonic Climatologies (1982-2008) (NODC Accession 0075098)

Data.gov (United States)

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

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...

Hanford Site Climatological Summary 2004 with Historical Data

International Nuclear Information System (INIS)

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

2005-01-01

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

Climatological study of Saclay site from 1958 to 1966. General climatology

International Nuclear Information System (INIS)

Levrard, Andre

1969-03-01

This document complements the CEA-N--0463 note with additional climatological measurements performed between 1963 and 1966 at the CEA Saclay centre, extending this survey over the 1958 to 1966 period. The duration, height, number of days and intensity of precipitations, the temperatures and vertical thermal gradient, the fog/mist and the wind direction and speed are reported monthly, seasonally and annually and presented in tables and diagrams

4 km NODC/RSMAS AVHRR Pathfinder Version 5.0 and 5.1 5-day Harmonic Climatologies (1982-2008) (NODC Accession 0071182)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains a global, 4km 5-day sea surface temperature climatology derived from harmonic analysis of the AVHRR Pathfinder Version 5.0 and 5.1 sea...

Observed Screen (Air) and GCM Surface/Screen Temperatures: Implications for Outgoing Longwave Fluxes at the Surface.

Science.gov (United States)

Garratt, J. R.

1995-05-01

There is direct evidence that excess net radiation calculated in general circulation models at continental surfaces [of about 11-17 W m2 (20%-27%) on an annual ~1 is not only due to overestimates in annual incoming shortwave fluxes [of 9-18 W m2 (6%-9%)], but also to underestimates in outgoing longwave fluxes. The bias in the outgoing longwave flux is deduced from a comparison of screen-air temperature observations, available as a global climatology of mean monthly values, and model-calculated surface and screen-air temperatures. An underestimate in the screen temperature computed in general circulation models over continents, of about 3 K on an annual basis, implies an underestimate in the outgoing longwave flux, averaged in six models under study, of 11-15 W m2 (3%-4%). For a set of 22 inland stations studied previously, the residual bias on an annual basis (the residual is the net radiation minus incoming shortwave plus outgoing longwave) varies between 18 and 23 W m2 for the models considered. Additional biases in one or both of the reflected shortwave and incoming longwave components cannot be ruled out.

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,...

Northeast Pacific Regional Climatology (NCEI Accession 0163799)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Northeast Pacific (NEP) new regional climatology is derived from the NCEI World Ocean Database archive of temperature and salinity and covers a time period from...

Validation of the Suomi NPP VIIRS Ice Surface Temperature Environmental Data Record

Directory of Open Access Journals (Sweden)

Yinghui Liu

2015-12-01

Full Text Available Continuous monitoring of the surface temperature is critical to understanding and forecasting Arctic climate change; as surface temperature integrates changes in the surface energy budget. The sea-ice surface temperature (IST has been measured with optical and thermal infrared sensors for many years. With the IST Environmental Data Record (EDR available from the Visible Infrared Imaging Radiometer Suite (VIIRS onboard the Suomi National Polar-orbiting Partnership (NPP and future Joint Polar Satellite System (JPSS satellites; we can continue to monitor and investigate Arctic climate change. This work examines the quality of the VIIRS IST EDR. Validation is performed through comparisons with multiple datasets; including NASA IceBridge measurements; air temperature from Arctic drifting ice buoys; Moderate Resolution Imaging Spectroradiometer (MODIS IST; MODIS IST simultaneous nadir overpass (SNO; and surface air temperature from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR reanalysis. Results show biases of −0.34; −0.12; 0.16; −3.20; and −3.41 K compared to an aircraft-mounted downward-looking pyrometer; MODIS; MODIS SNO; drifting buoy; and NCEP/NCAR reanalysis; respectively; root-mean-square errors of 0.98; 1.02; 0.95; 4.89; and 6.94 K; and root-mean-square errors with the bias removed of 0.92; 1.01; 0.94; 3.70; and 6.04 K. Based on the IceBridge and MODIS results; the VIIRS IST uncertainty (RMSE meets or exceeds the JPSS system requirement of 1.0 K. The product can therefore be considered useful for meteorological and climatological applications.

Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System

Science.gov (United States)

Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

2012-01-01

The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters

The role of land surface fluxes in Saudi-KAU AGCM: Temperature climatology over the Arabian Peninsula for the period 1981-2010

Science.gov (United States)

Ashfaqur Rahman, M.; Almazroui, Mansour; Nazrul Islam, M.; O'Brien, Enda; Yousef, Ahmed Elsayed

2018-02-01

A new version of the Community Land Model (CLM) was introduced to the Saudi King Abdulaziz University Atmospheric Global Climate Model (Saudi-KAU AGCM) for better land surface component representation, and so to enhance climate simulation. CLM replaced the original land surface model (LSM) in Saudi-KAU AGCM, with the aim of simulating more accurate land surface fluxes globally, but especially over the Arabian Peninsula. To evaluate the performance of Saudi-KAU AGCM, simulations were completed with CLM and LSM for the period 1981-2010. In comparison with LSM, CLM generates surface air temperature values that are closer to National Centre for Environmental Prediction (NCEP) observations. The global annual averages of land surface air temperature are 9.51, 9.52, and 9.57 °C for NCEP, CLM, and LSM respectively, although the same atmospheric radiative and surface forcing from Saudi-KAU AGCM are provided to both LSM and CLM at every time step. The better temperature simulations when using CLM can be attributed to the more comprehensive plant functional type and hierarchical tile approach to the land cover type in CLM, along with better parameterization of upward land surface fluxes compared to LSM. At global scale, CLM exhibits smaller annual and seasonal mean biases of temperature with respect to NCEP data. Moreover, at regional scale, CLM demonstrates reasonable seasonal and annual mean temperature over the Arabian Peninsula as compared to the Climatic Research Unit (CRU) data. Finally, CLM generated better matches to single point-wise observations of surface air temperature and surface fluxes for some case studies.

Climatology and trends of summer high temperature days in India ...

Indian Academy of Sciences (India)

patterns, there is clear change in climatological mean and coefficient of variation of HT days in a ... regions of India probably from mid 1990s. ... in extreme climate events are more sensitive to cli- ... C since mid-1990s in south, east, north.

A comparison of climatological observing windows and their impact on detecting daily temperature extrema

Science.gov (United States)

Žaknić-Ćatović, Ana; Gough, William A.

2018-04-01

Climatological observing window (COW) is defined as a time frame over which continuous or extreme air temperature measurements are collected. A 24-h time interval, ending at 00UTC or shifted to end at 06UTC, has been associated with difficulties in characterizing daily temperature extrema. A fixed 24-h COW used to obtain the temperature minima leads to potential misidentification due to fragmentation of "nighttime" into two subsequent nighttime periods due to the time discretization interval. The correct identification of air temperature extrema is achievable using a COW that identifies daily minimum over a single nighttime period and maximum over a single daytime period, as determined by sunrise and sunset. Due to a common absence of hourly air temperature observations, the accuracy of the mean temperature estimation is dependent on the accuracy of determination of diurnal air temperature extrema. Qualitative and quantitative criteria were used to examine the impact of the COW on detecting daily air temperature extrema. The timing of the 24-h observing window occasionally affects the determination of daily extrema through a mischaracterization of the diurnal minima and by extension can lead to errors in determining daily mean temperature. Hourly air temperature data for the time period from year 1987 to 2014, obtained from Toronto Buttonville Municipal Airport weather station, were used in analysis of COW impacts on detection of daily temperature extrema and calculation of annual temperature averages based on such extrema.

The anomalous high temperatures of November 2010 over Greece: meteorological and climatological aspects

Science.gov (United States)

Tolika, K.; Pytharoulis, I.; Maheras, P.

2011-10-01

This paper presents an analysis of the exceptionally high maximum (Tmax) and minimum (Tmin) temperatures which occurred during November 2010 and affected the entire Greek region. This severe "warm cold-season spell" was unusual because of its prolonged duration and intensity for the entire month and particularly the maximum temperature anomalies, which in comparison with the 1958-2000 climatological average, exceeded 5 °C at several stations. Comparing the observed record with future projections from three regional climate models revealed that Tmax and Tmin, on several days in November 2010, exceeded the 90th percentile of the simulated data. An examination of the atmospheric - synoptic conditions during this period showed that the anomalous high temperatures could probably be related to the negative phase of the Eastern Mediterranean Pattern (EMP), with an intense pole of negative anomalies located over the British Isles, and to the east, a second pole of positive anomalies, centred over the Caspian Sea. Finally, an attempt is made to further investigate the mechanisms responsible for this phenomenon, for example, the thermal forcing in the tropics (Niño 3 or Niño 3.4).

What spatial scales are believable for climate model projections of sea surface temperature?

Science.gov (United States)

Kwiatkowski, Lester; Halloran, Paul R.; Mumby, Peter J.; Stephenson, David B.

2014-09-01

Earth system models (ESMs) provide high resolution simulations of variables such as sea surface temperature (SST) that are often used in off-line biological impact models. Coral reef modellers have used such model outputs extensively to project both regional and global changes to coral growth and bleaching frequency. We assess model skill at capturing sub-regional climatologies and patterns of historical warming. This study uses an established wavelet-based spatial comparison technique to assess the skill of the coupled model intercomparison project phase 5 models to capture spatial SST patterns in coral regions. We show that models typically have medium to high skill at capturing climatological spatial patterns of SSTs within key coral regions, with model skill typically improving at larger spatial scales (≥4°). However models have much lower skill at modelling historical warming patters and are shown to often perform no better than chance at regional scales (e.g. Southeast Asian) and worse than chance at finer scales (coral bleaching frequency and other marine processes linked to SST warming.

Surface temperatures in the polar regions from Nimbus 7 temperature humidity infrared radiometer

Science.gov (United States)

Comiso, Josefino C.

1994-01-01

Monthly surface temperatures in the Arctic and Antarctic regions have been derived from the 11.5 micrometer thermal infrared channel of the Nimbus 7 temperature humidity infrared radiometer (THIR) for a whole year in 1979 and for a winter and a summer month from 1980 through 1985. The data set shows interannual variability and provides spatial details that allow identification of temperature patterns over sea ice and ice sheet surfaces. For example, the coldest spot in the southern hemisphere is observed to be consistently in the Antarctic plateau in the southern hemisphere, while that in the northern hemisphere is usually located in Greenland, or one of three other general areas: Siberia, the central Arctic, or the Canadian Archipelago. Also, in the southern hemisphere, the amplitude of the seasonal fluctuation of ice sheet temperatures is about 3 times that of sea ice, while in the northern hemisphere, the corresponding fluctuations for the two surfaces are about the same. The main sources of error in the retrieval are cloud and other atmospheric effects. These were minimized by first choosing the highest radiance value from the set of measurements during the day taken within a 30 km by 30 km grid of each daily map. Then the difference of daily maps was taken and where the difference is greater than a certain threshold (which in this case is 12 C), the data element is deleted. Overall, the monthly maps derived from the resulting daily maps are spatially and temporally consistent, are coherent with the topograph y of the Antarctic continent and the location of the sea ice edge, and are in qualitative agreement with climatological data. Quantitatively, THIR data are in good agreement with Antarctic ice sheet surface air temperature station data with a correlation coefficient of 0.997 and a standard deviation of 2.0 C. The absolute values are not as good over the sea ice edges, but a comparison with Russian 2-m drift station temperatures shows very high correlation

Effects of undetected data quality issues on climatological analyses

Directory of Open Access Journals (Sweden)

S. Hunziker

2018-01-01

Full Text Available Systematic data quality issues may occur at various stages of the data generation process. They may affect large fractions of observational datasets and remain largely undetected with standard data quality control. This study investigates the effects of such undetected data quality issues on the results of climatological analyses. For this purpose, we quality controlled daily observations of manned weather stations from the Central Andean area with a standard and an enhanced approach. The climate variables analysed are minimum and maximum temperature and precipitation. About 40 % of the observations are inappropriate for the calculation of monthly temperature means and precipitation sums due to data quality issues. These quality problems undetected with the standard quality control approach strongly affect climatological analyses, since they reduce the correlation coefficients of station pairs, deteriorate the performance of data homogenization methods, increase the spread of individual station trends, and significantly bias regional temperature trends. Our findings indicate that undetected data quality issues are included in important and frequently used observational datasets and hence may affect a high number of climatological studies. It is of utmost importance to apply comprehensive and adequate data quality control approaches on manned weather station records in order to avoid biased results and large uncertainties.

The anomalous high temperatures of November 2010 over Greece: meteorological and climatological aspects

Directory of Open Access Journals (Sweden)

K. Tolika

2011-10-01

Full Text Available This paper presents an analysis of the exceptionally high maximum (T_max and minimum (T_min temperatures which occurred during November 2010 and affected the entire Greek region. This severe "warm cold-season spell" was unusual because of its prolonged duration and intensity for the entire month and particularly the maximum temperature anomalies, which in comparison with the 1958–2000 climatological average, exceeded 5 °C at several stations. Comparing the observed record with future projections from three regional climate models revealed that T_max and T_min, on several days in November 2010, exceeded the 90th percentile of the simulated data. An examination of the atmospheric – synoptic conditions during this period showed that the anomalous high temperatures could probably be related to the negative phase of the Eastern Mediterranean Pattern (EMP, with an intense pole of negative anomalies located over the British Isles, and to the east, a second pole of positive anomalies, centred over the Caspian Sea. Finally, an attempt is made to further investigate the mechanisms responsible for this phenomenon, for example, the thermal forcing in the tropics (Niño 3 or Niño 3.4.

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).

Climatological Downscaling and Evaluation of AGRMET Precipitation Analyses Over the Continental U.S.

Science.gov (United States)

Garcia, M.; Peters-Lidard, C. D.; Eylander, J. B.; Daly, C.; Tian, Y.; Zeng, J.

2007-05-01

The spatially distributed application of a land surface model (LSM) over a region of interest requires the application of similarly distributed precipitation fields that can be derived from various sources, including surface gauge networks, surface-based radar, and orbital platforms. The spatial variability of precipitation influences the spatial organization of soil temperature and moisture states and, consequently, the spatial variability of land- atmosphere fluxes. The accuracy of spatially-distributed precipitation fields can contribute significantly to the uncertainty of model-based hydrological states and fluxes at the land surface. Collaborations between the Air Force Weather Agency (AFWA), NASA, and Oregon State University have led to improvements in the processing of meteorological forcing inputs for the NASA-GSFC Land Information System (LIS; Kumar et al. 2006), a sophisticated framework for LSM operation and model coupling experiments. Efforts at AFWA toward the production of surface hydrometeorological products are currently in transition from the legacy Agricultural Meteorology modeling system (AGRMET) to use of the LIS framework and procedures. Recent enhancements to meteorological input processing for application to land surface models in LIS include the assimilation of climate-based information for the spatial interpolation and downscaling of precipitation fields. Climatological information included in the LIS-based downscaling procedure for North America is provided by a monthly high-resolution PRISM (Daly et al. 1994, 2002; Daly 2006) dataset based on a 30-year analysis period. The combination of these sources and methods attempts to address the strengths and weaknesses of available legacy products, objective interpolation methods, and the PRISM knowledge-based methodology. All of these efforts are oriented on an operational need for timely estimation of spatial precipitation fields at adequate spatial resolution for customer dissemination and

Climatology

International Nuclear Information System (INIS)

Schoenwiese, C.D.

1994-01-01

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.) [de

Influence of Kuroshio SST front in the East China Sea on the climatological evolution of Meiyu rainband

Science.gov (United States)

Xu, Mimi; Xu, Haiming; Ren, Huijun

2018-02-01

The influence of Kuroshio sea surface temperature (SST) front in the East China Sea (ECS) on the temporal evolution of climatological Meiyu rainband was investigated using a suite of high-resolution satellite observations and a reanalysis dataset from 2000 to 2011. During the northward seasonal march of Meiyu rainband from the warmer flank of the SST front to the colder flank, the climatological rainband strength weakened substantially despite large-scale environment became more conducive to intensify precipitation. A sharp reduction in occurrence frequency of precipitation with relatively shallower depth and smaller intensity was responsible for the weakening of Meiyu rainband. During the northward migration of Meiyu rainband, individual precipitation events became deeper and more intensive, and the contribution of convective precipitation to the rainband was enhanced, associated with the seasonal northward extension of high convective instability region over the ECS. The characteristics of Meiyu rainband evolution were generally supported by cloud observations. When Meiyu rainband was located on the warmer flank of the SST front, local enhanced mean surface wind convergence and variance of convergence at synoptic timescale by the warm SST of the Kuroshio favored strong surface convergence that may trigger precipitation. A detailed moisture budget analysis revealed that the major part of moisture for Meiyu precipitation was supplied by low-level wind convergence, with much smaller contribution from moisture advection. The variation of climatological precipitation associated with Meiyu northward migration depended on SST modulation of both surface evaporation and low-level moisture convergence over the ECS.

A Satellite-Derived Climatological Analysis of Urban Heat Island over Shanghai during 2000–2013

Directory of Open Access Journals (Sweden)

Weijiao Huang

2017-06-01

Full Text Available The urban heat island is generally conducted based on ground observations of air temperature and remotely sensing of land surface temperature (LST. Satellite remotely sensed LST has the advantages of global coverage and consistent periodicity, which overcomes the weakness of ground observations related to sparse distributions and costs. For human related studies and urban climatology, canopy layer urban heat island (CUHI based on air temperatures is extremely important. This study has employed remote sensing methodology to produce monthly CUHI climatology maps during the period 2000–2013, revealing the spatiotemporal characteristics of daytime and nighttime CUHI during this period of rapid urbanization in Shanghai. Using stepwise linear regression, daytime and nighttime air temperatures at the four overpass times of Terra/Aqua were estimated based on time series of Terra/Aqua-MODIS LST and other auxiliary variables including enhanced vegetation index, normalized difference water index, solar zenith angle and distance to coast. The validation results indicate that the models produced an accuracy of 1.6–2.6 °C RMSE for the four overpass times of Terra/Aqua. The models based on Terra LST showed higher accuracy than those based on Aqua LST, and nighttime air temperature estimation had higher accuracy than daytime. The seasonal analysis shows daytime CUHI is strongest in summer and weakest in winter, while nighttime CUHI is weakest in summer and strongest in autumn. The annual mean daytime CUHI during 2000–2013 is 1.0 and 2.2 °C for Terra and Aqua overpass, respectively. The annual mean nighttime CUHI is about 1.0 °C for both Terra and Aqua overpass. The resultant CUHI climatology maps provide a spatiotemporal quantification of CUHI with emphasis on temperature gradients. This study has provided information of relevance to urban planners and environmental managers for assessing and monitoring urban thermal environments which are constantly

Downscaling the Impacts of Large-Scale LUCC on Surface Temperature along with IPCC RCPs: A Global Perspective

Directory of Open Access Journals (Sweden)

Xiangzheng Deng

2014-04-01

Full Text Available This study focuses on the potential impacts of large-scale land use and land cover changes (LUCC on surface temperature from a global perspective. As important types of LUCC, urbanization, deforestation, cultivated land reclamation, and grassland degradation have effects on the climate, the potential changes of the surface temperature caused by these four types of large-scale LUCC from 2010 to 2050 are downscaled, and this issue analyzed worldwide along with Representative Concentration Pathways (RCPs of the Intergovernmental Panel on Climate Change (IPCC. The first case study presents some evidence of the effects of future urbanization on surface temperature in the Northeast megalopolis of the United States of America (USA. In order to understand the potential climatological variability caused by future forest deforestation and vulnerability, we chose Brazilian Amazon region as the second case study. The third selected region in India as a typical region of cultivated land reclamation where the possible climatic impacts are explored. In the fourth case study, we simulate the surface temperature changes caused by future grassland degradation in Mongolia. Results show that the temperature in built-up area would increase obviously throughout the four land types. In addition, the effects of all four large-scale LUCC on monthly average temperature change would vary from month to month with obviously spatial heterogeneity.

Wintertime sea surface temperature fronts in the Taiwan Strait

Science.gov (United States)

Chang, Yi; Shimada, Teruhisa; Lee, Ming-An; Lu, Hsueh-Jung; Sakaida, Futoki; Kawamura, Hiroshi

2006-12-01

We present wintertime variations and distributions of sea surface temperature (SST) fronts in the Taiwan Strait by applying an entropy-based edge detection method to 10-year (1996-2005) satellite SST images with grid size of 0.01°. From climatological monthly mean maps of SST gradient magnitude in winter, we identify four significant SST fronts in the Taiwan Strait. The Mainland China Coastal Front is a long frontal band along the 50-m isobath near the Chinese coast. The sharp Peng-Chang Front appears along the Peng-Hu Channel and extends northward around the Chang-Yuen Ridge. The Taiwan Bank Front evolves in early winter. As the winter progresses, the front becomes broad and moves toward the Chinese coast, connecting to the Mainland China Coastal Front. The Kuroshio Front extends northeastward from the northeastern tip of Taiwan with a semicircle-shape curving along the 100-m isobath.

Correlation and multifractality in climatological time series

International Nuclear Information System (INIS)

Pedron, I T

2010-01-01

Climate can be described by statistical analysis of mean values of atmospheric variables over a period. It is possible to detect correlations in climatological time series and to classify its behavior. In this work the Hurst exponent, which can characterize correlation and persistence in time series, is obtained by using the Detrended Fluctuation Analysis (DFA) method. Data series of temperature, precipitation, humidity, solar radiation, wind speed, maximum squall, atmospheric pressure and randomic series are studied. Furthermore, the multifractality of such series is analyzed applying the Multifractal Detrended Fluctuation Analysis (MF-DFA) method. The results indicate presence of correlation (persistent character) in all climatological series and multifractality as well. A larger set of data, and longer, could provide better results indicating the universality of the exponents.

An aerosol optical depth climatology for NOAA's national surface radiation budget network (SURFRAD)

Science.gov (United States)

Augustine, John A.; Hodges, Gary B.; Dutton, Ellsworth G.; Michalsky, Joseph J.; Cornwall, Christopher R.

2008-06-01

A series of algorithms developed to process spectral solar measurements for aerosol optical depth (AOD) for the National Oceanic and Atmospheric Administration's (NOAA) national surface radiation budget network (SURFRAD) is summarized, and decadal results are presented. AOD is a measure of the extinction of the Sun's beam due to aerosols. Daily files of AOD for five spectral measurements in the visible and near-infrared have been produced for 1997-2006. Comparisons of SURFRAD daily AOD averages to NASA's Aerosol Robotic Network product at two of the stations were generally good. An AOD climatology for each SURFRAD station is presented as an annual time series of composite monthly means that represents a typical intra-annual AOD variation. Results are similar to previous U.S. climatologies in that the highest AOD magnitude and greatest variability occur in summer, the lowest AOD levels are in winter, and geographically, the highest-magnitude AOD is in the eastern United States. Springtime Asian dust intrusions show up as a secondary maximum at the western stations. A time series of nationwide annual means shows that 500-nm AOD has decreased over the United States by about 0.02 AOD units over the 10-year period. However, this decline is not statistically significant nor geographically consistent within the country. The eastern U.S. stations and westernmost station at Desert Rock, Nevada, show decreasing AOD, whereas the other two western stations show an increase that is attributed to an upsurge in wildfire activity in the last half of the decade.

Temporal variability and climatology of hydrodynamic, water property and water quality parameters in the West Johor Strait of Singapore.

Science.gov (United States)

Behera, Manasa Ranjan; Chun, Cui; Palani, Sundarambal; Tkalich, Pavel

2013-12-15

The study presents a baseline variability and climatology study of measured hydrodynamic, water properties and some water quality parameters of West Johor Strait, Singapore at hourly-to-seasonal scales to uncover their dependency and correlation to one or more drivers. The considered parameters include, but not limited by sea surface elevation, current magnitude and direction, solar radiation and air temperature, water temperature, salinity, chlorophyll-a and turbidity. FFT (Fast Fourier Transform) analysis is carried out for the parameters to delineate relative effect of tidal and weather drivers. The group and individual correlations between the parameters are obtained by principal component analysis (PCA) and cross-correlation (CC) technique, respectively. The CC technique also identifies the dependency and time lag between driving natural forces and dependent water property and water quality parameters. The temporal variability and climatology of the driving forces and the dependent parameters are established at the hourly, daily, fortnightly and seasonal scales. Copyright © 2013 Elsevier Ltd. All rights reserved.

Climatological Implications of Deep-Rooting in Water-Limited Ecosystems

Science.gov (United States)

Amenu, G. G.; Kumar, P.

2005-12-01

In vegetated ecosystems, plants are the primary channels that connect the soil with the atmosphere (through water, energy, carbon, and nutrient cycles), with plant roots controlling the below-ground dynamics. Recently, several observational evidences are emerging which suggests the existence of plant roots much deeper in the soil/rock profile than the depth usually perceived in existing hydroclimatological and hydroecological models. In this study, using land surface model, we assess the effects of vegetation deep-rooting on (a) moisture and temperature redistribution in the soil profile, (b) energy flux partitioning at the land surface, and (c) net primary productivity of vegetated ecosystems. Three sites characterized by different vegetation, soil, and climate (all located in arid to sub-humid regions of the United States) were studied. The sites include the Mogollon Rim in Arizona, the Edwards Plateau in Texas, and the Southern Piedmont in Georgia. Soil depths of up to 10 m are investigated. Results of this modeling effort and its implications for climatological modeling will be presented.

A climatological model for risk computations incorporating site- specific dry deposition influences

International Nuclear Information System (INIS)

Droppo, J.G. Jr.

1991-07-01

A gradient-flux dry deposition module was developed for use in a climatological atmospheric transport model, the Multimedia Environmental Pollutant Assessment System (MEPAS). The atmospheric pathway model computes long-term average contaminant air concentration and surface deposition patterns surrounding a potential release site incorporating location-specific dry deposition influences. Gradient-flux formulations are used to incorporate site and regional data in the dry deposition module for this atmospheric sector-average climatological model. Application of these formulations provide an effective means of accounting for local surface roughness in deposition computations. Linkage to a risk computation module resulted in a need for separate regional and specific surface deposition computations. 13 refs., 4 figs., 2 tabs

Using Self-Organizing Map (SOM) Clusters of Ozonesonde Profiles to Evaluate Climatologies and Create Linkages between Meteorology and Pollution

Science.gov (United States)

Stauffer, R. M.; Thompson, A. M.; Young, G. S.; Oltmans, S. J.; Johnson, B.

2016-12-01

Ozone (O3) climatologies are typically created by averaging ozonesonde profiles on a monthly or seasonal basis, either for specific regions or zonally. We demonstrate the advantages of using a statistical clustering technique, self-organizing maps (SOM), over this simple averaging, through analysis of more than 4500 sonde profiles taken from the long-term US sites at Boulder, CO; Huntsville, AL; Trinidad Head, CA; and Wallops Island, VA. First, we apply SOM to O3 mixing ratios from surface to 12 km amsl. At all four sites, profiles in SOM clusters exhibit similar tropopause height, 500 hPa height and temperature, and total and tropospheric column O3. Second, when profiles from each SOM cluster are compared to monthly O3 means, near-tropopause O3 in three of the clusters is double (over +100 ppbv) the climatological O3 mixing ratio. The three clusters include 13-16% of all profiles, mostly from winter and spring. Large mid-tropospheric deviations from monthly means are found in two highly-populated clusters that represent either distinctly polluted (summer) or clean O3 (fall-winter, high tropopause) profiles. Thus, SOM indeed appear to represent US O3 profile statistics better than conventional climatologies. In the case of Trinidad Head, SOM clusters of O3 profile data from the lower troposphere (surface-6 km amsl) can discriminate background vs polluted O3 and the meteorology associated with each. Two of nine O3 clusters exhibit thin layers ( 100s of m thick) of high O3, typically between 1 and 4 km. Comparisons between clusters and downwind, high-altitude surface O3 measurements display a marked impact of the elevated tropospheric O­­3. Days corresponding to the high O3 clusters exhibit hourly surface O3 anomalies at surface sites of +5 -10 ppbv compared to a climatology; the anomalies can last up to four days. We also explore applications of SOM to tropical ozonesonde profiles, where tropospheric O3 variability is generally smaller.

Famine Early Warning Systems Network (FEWS NET) Agro-climatology Analysis Tools and Knowledge Base Products for Food Security Applications

Science.gov (United States)

Budde, M. E.; Rowland, J.; Anthony, M.; Palka, S.; Martinez, J.; Hussain, R.

2017-12-01

The U.S. Geological Survey (USGS) supports the use of Earth observation data for food security monitoring through its role as an implementing partner of the Famine Early Warning Systems Network (FEWS NET). The USGS Earth Resources Observation and Science (EROS) Center has developed tools designed to aid food security analysts in developing assumptions of agro-climatological outcomes. There are four primary steps to developing agro-climatology assumptions; including: 1) understanding the climatology, 2) evaluating current climate modes, 3) interpretation of forecast information, and 4) incorporation of monitoring data. Analysts routinely forecast outcomes well in advance of the growing season, which relies on knowledge of climatology. A few months prior to the growing season, analysts can assess large-scale climate modes that might influence seasonal outcomes. Within two months of the growing season, analysts can evaluate seasonal forecast information as indicators. Once the growing season begins, monitoring data, based on remote sensing and field information, can characterize the start of season and remain integral monitoring tools throughout the duration of the season. Each subsequent step in the process can lead to modifications of the original climatology assumption. To support such analyses, we have created an agro-climatology analysis tool that characterizes each step in the assumption building process. Satellite-based rainfall and normalized difference vegetation index (NDVI)-based products support both the climatology and monitoring steps, sea-surface temperature data and knowledge of the global climate system inform the climate modes, and precipitation forecasts at multiple scales support the interpretation of forecast information. Organizing these data for a user-specified area provides a valuable tool for food security analysts to better formulate agro-climatology assumptions that feed into food security assessments. We have also developed a knowledge

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 (Japan Society for the Promotion of Science (JSPS) KAKENHI (Grants-in-Aid for Scientific Research) grant number 25350515 and the Japan Aerospace Exploration Agency (JAXA) 7th Research Announcement (RA).

The impact of implementing the bare essentials of surface transfer land surface scheme into the BMRC GCM

Energy Technology Data Exchange (ETDEWEB)

Yang, Z.L. [Univ. of Arizona, Tucson, AZ (United States); Pitman, A.J. [Macquarie Univ., Sydney (Australia); McAvaney, B. [Bureau of Meterology Research Centre, Melbourne (Australia)] [and others

1995-07-01

This study describes the first order impacts of incorporating a complex land-surface scheme, the bare essentials of surface transfer (BEST), into the Australian Bureau of Meteorology Research Centre (BMRC) global atmospheric general circulation model (GCM). Land seasonal climatologies averaged over the last six years of integrations after equilibrium from the GCM with BEST and without BEST (the control) are compared. The modeled results are evaluated with comprehensive sources of data, including the layer-cloud climatologies project (ISCCP) data from 1983 to 1991 and the surface-observed global data of Warrent et al., a five-year climatology of surface albedo estimated from earth radiation budget experiment (ERBE) top-of-the-atmosphere (TOA) radiative fluxes, global grid point datasets of precipitation, and the climatological analyses of surface evaporation and albedo. Emphasis is placed on the surface evaluation of simulations of land-surface conditions such as surface roughness, surface albedo and the surface wetness factor, and on their effects on surface evaporation, precipitation, layer-cloud and surface temperature. The improvements due to the inclusion of BEST are: a realistic geographical distribution of surface roughness, a decrease in surface albedo over areas with seasonal snow cover, an an increase in surface albedo over snow-free land. The simulated reduction in surface evaporation due, in part, to the bio-physical control of vegetation, is also consistent with the previous studies. Since the control climate has a dry bias, the overall simulations from the GCM with BEST are degraded, except for significant improvements for the northern winter hemisphere because of the realistic vegetation-masking effects. The implications of our results for synergistic developments of other aspects of model parameterization schemes such as boundary layer dynamics, clouds, convection and rainfall are discussed. 82 refs., 9 figs., 3 tabs.

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.

The global climatology of an interannually varying air-sea flux data set

Energy Technology Data Exchange (ETDEWEB)

Large, W.G.; Yeager, S.G. [National Center for Atmospheric Research, Boulder, CO (United States)

2009-08-15

The air-sea fluxes of momentum, heat, freshwater and their components have been computed globally from 1948 at frequencies ranging from 6-hourly to monthly. All fluxes are computed over the 23 years from 1984 to 2006, but radiation prior to 1984 and precipitation before 1979 are given only as climatological mean annual cycles. The input data are based on NCEP reanalysis only for the near surface vector wind, temperature, specific humidity and density, and on a variety of satellite based radiation, sea surface temperature, sea-ice concentration and precipitation products. Some of these data are adjusted to agree in the mean with a variety of more reliable satellite and in situ measurements, that themselves are either too short a duration, or too regional in coverage. The major adjustments are a general increase in wind speed, decrease in humidity and reduction in tropical solar radiation. The climatological global mean air-sea heat and freshwater fluxes (1984-2006) then become 2 W/m{sup 2} and -0.1 mg/m{sup 2} per second, respectively, down from 30 W/m{sup 2} and 3.4 mg/m{sup 2} per second for the unaltered data. However, decadal means vary from 7.3 W/m{sup 2} (1977-1986) to -0.3 W/m{sup 2} (1997-2006). The spatial distributions of climatological fluxes display all the expected features. A comparison of zonally averaged wind stress components across ocean sub-basins reveals large differences between available products due both to winds and to the stress calculation. Regional comparisons of the heat and freshwater fluxes reveal an alarming range among alternatives; typically 40 W/m{sup 2} and 10 mg/m{sup 2} per second, respectively. The implied ocean heat transports are within the uncertainty of estimates from ocean observations in both the Atlantic and Indo-Pacific basins. They show about 2.4 PW of tropical heating, of which 80% is transported to the north, mostly in the Atlantic. There is similar good agreement in freshwater transport at many latitudes in both

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

International Nuclear Information System (INIS)

Bolle, H.J.; Katergiannakis, U.; Billing, H.; Koslowsky, D.; Langer, I.; Tonn, W.

1993-01-01

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.) [de

ANALYSING THE EFFECTS OF DIFFERENT LAND COVER TYPES ON LAND SURFACE TEMPERATURE USING SATELLITE DATA

Directory of Open Access Journals (Sweden)

A. Şekertekin

2015-12-01

Full Text Available Monitoring Land Surface Temperature (LST via remote sensing images is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and it also helps us to understand the behavior of urban heat islands. There are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. In this research, mono window algorithm was implemented to Landsat 5 TM image acquired on 28.08.2011. Besides, meteorological data such as humidity and temperature are used in the algorithm. Moreover, high resolution Geoeye-1 and Worldview-2 images acquired on 29.08.2011 and 12.07.2013 respectively were used to investigate the relationships between LST and land cover type. As a result of the analyses, area with vegetation cover has approximately 5 ºC lower temperatures than the city center and arid land., LST values change about 10 ºC in the city center because of different surface properties such as reinforced concrete construction, green zones and sandbank. The temperature around some places in thermal power plant region (ÇATES and ZETES Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature due to the land cover structure.

Analysing the Effects of Different Land Cover Types on Land Surface Temperature Using Satellite Data

Science.gov (United States)

Şekertekin, A.; Kutoglu, Ş. H.; Kaya, S.; Marangoz, A. M.

2015-12-01

Monitoring Land Surface Temperature (LST) via remote sensing images is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and it also helps us to understand the behavior of urban heat islands. There are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. In this research, mono window algorithm was implemented to Landsat 5 TM image acquired on 28.08.2011. Besides, meteorological data such as humidity and temperature are used in the algorithm. Moreover, high resolution Geoeye-1 and Worldview-2 images acquired on 29.08.2011 and 12.07.2013 respectively were used to investigate the relationships between LST and land cover type. As a result of the analyses, area with vegetation cover has approximately 5 ºC lower temperatures than the city center and arid land., LST values change about 10 ºC in the city center because of different surface properties such as reinforced concrete construction, green zones and sandbank. The temperature around some places in thermal power plant region (ÇATES and ZETES) Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature due to the land cover structure.

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 under......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...... considered. The interdisciplinary approach reveals information and perspective that go beyond the study of cli ate and hydro gy alone...

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.

Los Alamos Climatology 2016 Update

Energy Technology Data Exchange (ETDEWEB)

Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-10

The Los Alamos National Laboratory (LANL or the Laboratory) operates a meteorology monitoring network to support LANL emergency response, engineering designs, environmental compliance, environmental assessments, safety evaluations, weather forecasting, environmental monitoring, research programs, and environmental restoration. Weather data has been collected in Los Alamos since 1910. Bowen (1990) provided climate statistics (temperature and precipitation) for the 1961– 1990 averaging period, and included other analyses (e.g., wind and relative humidity) based on the available station locations and time periods. This report provides an update to the 1990 publication Los Alamos Climatology (Bowen 1990).

Climatology and internal variability in a 1000-year control simulation with the coupled climate model ECHO-G

Energy Technology Data Exchange (ETDEWEB)

Min, S.K.; Hense, A. [Bonn Univ. (Germany). Meteorologisches Inst.; Legutke, S.; Kwon, W.T. [Korea Meteorological Administration, Seoul (Korea). Meteorological Research Inst.

2004-03-01

The climatology and internal variability in a 1000-year control simulation of the coupled atmosphere-ocean global climate model ECHO-G are analyzed and compared with observations and other coupled climate model simulations. ECHO-G requires annual mean flux corrections for heat and freshwater in order to simulate no climate drift for 1000 years, but no flux corrections for momentum. The ECHO-G control run captures well most aspects of the observed seasonal and annual climatology and of the interannual to decadal variability. Model biases are very close to those in ECHAM4 stand-alone integrations with prescribed observed sea surface temperature. A trend comparison between observed and modeled near surface temperatures shows that the observed global warming at near surface level is beyond the range of internal variability produced by ECHO-G. The simulated global mean near surface temperatures, however, show a two-year spectral peak which is linked with a strong biennial bias of energy in the ENSO signal. Consequently, the interannual variability (3-9 years) is underestimated. The overall ENSO structure such as the tropical SST climate and its seasonal cycle, a single ITCZ in the eastern tropical Pacific, and the ENSO phase-locking to the annual cycle are simulated reasonably well by ECHO-G. However, the amplitude of SST variability is overestimated in the eastern equatorial pacific and the observed westward propagation of zonal wind stress over the equatorial pacific is not captured by the model. ENSO-related teleconnection patterns of near surface temperature, precipitation, and mean sea level pressure are reproduced realistically. The station-based NAO index in the model exhibits a 'white' noise spectrum similar to the observed and the NAO-related patterns of near surface temperature, precipitation, and mean sea level pressure are also simulated successfully. However, the model overestimates the additional warming over the north pacific in the high index

Temporal variability and climatology of hydrodynamic, water property and water quality parameters in the West Johor Strait of Singapore

International Nuclear Information System (INIS)

Behera, Manasa Ranjan; Chun, Cui; Palani, Sundarambal; Tkalich, Pavel

2013-01-01

Highlights: • Water temperature is driven by solar radiation and air temperature in the West Johor Strait (WJS). • Salinity in WJS is driven by flood-ebb tide and seasonal variability due to monsoon. • Turbidity is mainly dependent on tidal current and river discharge in WJS. • Chl-a concentration increases with increase in air and water temperature in WJS. • Near-bottom Chl-a concentration in the WJS is high during SW monsoon. -- Abstract: The study presents a baseline variability and climatology study of measured hydrodynamic, water properties and some water quality parameters of West Johor Strait, Singapore at hourly-to-seasonal scales to uncover their dependency and correlation to one or more drivers. The considered parameters include, but not limited by sea surface elevation, current magnitude and direction, solar radiation and air temperature, water temperature, salinity, chlorophyll-a and turbidity. FFT (Fast Fourier Transform) analysis is carried out for the parameters to delineate relative effect of tidal and weather drivers. The group and individual correlations between the parameters are obtained by principal component analysis (PCA) and cross-correlation (CC) technique, respectively. The CC technique also identifies the dependency and time lag between driving natural forces and dependent water property and water quality parameters. The temporal variability and climatology of the driving forces and the dependent parameters are established at the hourly, daily, fortnightly and seasonal scales

Inverse analysis of inner surface temperature history from outer surface temperature measurement of a pipe

International Nuclear Information System (INIS)

Kubo, S; Ioka, S; Onchi, S; Matsumoto, Y

2010-01-01

When slug flow runs through a pipe, nonuniform and time-varying thermal stresses develop and there is a possibility that thermal fatigue occurs. Therefore it is necessary to know the temperature distributions and the stress distributions in the pipe for the integrity assessment of the pipe. It is, however, difficult to measure the inner surface temperature directly. Therefore establishment of the estimation method of the temperature history on inner surface of pipe is needed. As a basic study on the estimation method of the temperature history on the inner surface of a pipe with slug flow, this paper presents an estimation method of the temperature on the inner surface of a plate from the temperature on the outer surface. The relationship between the temperature history on the outer surface and the inner surface is obtained analytically. Using the results of the mathematical analysis, the inverse analysis method of the inner surface temperature history estimation from the outer surface temperature history is proposed. It is found that the inner surface temperature history can be estimated from the outer surface temperature history by applying the inverse analysis method, even when it is expressed by the multiple frequency components.

Evaluation of Surface Fatigue Strength Based on Surface Temperature

Science.gov (United States)

Deng, Gang; Nakanishi, Tsutomu

Surface temperature is considered to be an integrated index that is dependent on not only the load and the dimensions at the contact point but also the sliding velocity, rolling velocity, surface roughness, and lubrication conditions. Therefore, the surface durability of rollers and gears can be evaluated more exactly and simply by the use of surface temperature rather than Hertzian stress. In this research, surface temperatures of rollers under different rolling and sliding conditions are measured using a thermocouple. The effects of load P, mean velocity Vm and sliding velocity Vs on surface temperature are clarified. An experimental formula, which expresses the linear relationship between surface temperature and the P0.86Vs1.31Vm-0.83 value, is used to determine surface temperature. By comparing calculated and measured temperature on the tooth surface of a gear, this formula is confirmed to be applicable for gear tooth surface temperature calculation.

A European satellite-derived UV climatology available for impact studies

International Nuclear Information System (INIS)

Verdebout, J.

2004-01-01

This paper presents a satellite-derived climatology of the surface UV radiation, intended to support impact studies on the environment and human health. As of today, the dataset covers the period from 1 January 1984 to 31 August 2003, with daily dose maps covering Europe with a spatial resolution of 0.05 deg.. A comparison between the modelled erythemal daily dose and measurements in Ispra yields an r.m.s value with a relative difference of 29% and a bias of 3%. The seemingly large dispersion is, however, due to a restricted number of days for which the relative difference is very high. The climatological dataset documents systematic patterns in the geographical distribution of the surface UV radiation due to cloudiness, altitude and snow. It also shows a large year-to-year variability in monthly doses of up to ±50% in spring and ±30% in summer. (authors)

Role of the Soil Thermal Inertia in the short term variability of the surface temperature and consequences for the soil-moisture temperature feedback

Science.gov (United States)

Cheruy, Frederique; Dufresne, Jean-Louis; Ait Mesbah, Sonia; Grandpeix, Jean-Yves; Wang, Fuxing

2017-04-01

A simple model based on the surface energy budget at equilibrium is developed to compute the sensitivity of the climatological mean daily temperature and diurnal amplitude to the soil thermal inertia. It gives a conceptual framework to quantity the role of the atmospheric and land surface processes in the surface temperature variability and relies on the diurnal amplitude of the net surface radiation, the sensitivity of the turbulent fluxes to the surface temperature and the thermal inertia. The performances of the model are first evaluated with 3D numerical simulations performed with the atmospheric (LMDZ) and land surface (ORCHIDEE) modules of the Institut Pierre Simon Laplace (IPSL) climate model. A nudging approach is adopted, it prevents from using time-consuming long-term simulations required to account for the natural variability of the climate and allow to draw conclusion based on short-term (several years) simulations. In the moist regions the diurnal amplitude and the mean surface temperature are controlled by the latent heat flux. In the dry areas, the relevant role of the stability of the boundary layer and of the soil thermal inertia is demonstrated. In these regions, the sensitivity of the surface temperature to the thermal inertia is high, due to the high contribution of the thermal flux to the energy budget. At high latitudes, when the sensitivity of turbulent fluxes is dominated by the day-time sensitivity of the sensible heat flux to the surface temperature and when this later is comparable to the thermal inertia term of the sensitivity equation, the surface temperature is also partially controlled by the thermal inertia which can rely on the snow properties; In the regions where the latent heat flux exhibits a high day-to-day variability, such as transition regions, the thermal inertia has also significant impact on the surface temperature variability . In these not too wet (energy limited) and not too dry (moisture-limited) soil moisture (SM

Climatological background for the utilization of energy from the sun

International Nuclear Information System (INIS)

Alterio, S.; Barabaro, S.; Coppolino, S.

1983-01-01

Information on the main climatological factors characterizing a given place or area is fundamental for the utilization of energy from the Sun and for other applications. This paper collects and analyses the daily, monthly and yearly average climatic data (insolation, sunshine, state of the sky, air temperature and relative humidity) provided by sixty thermopluviometric stations variously distributed in the territory of Sicily. The analysis is here performed both with a purely applicative view and in order to point out the connection between climate and physical environment. It leads to a better knowledge of solar climate and constitutes the basis for equally interesting further developments in the various fields of applied climatology: geomorfology, agriculture, biology, ecology, bioclimatology, etc

Internal variability in a 1000-yr control simulation with the coupled climate model ECHO-G - I. Near-surface temperature, precipitation and mean sea level pressure.

Energy Technology Data Exchange (ETDEWEB)

Min, Seung-Ki; Hense, Andreas [Univ. of Bonn (Germany). Meteorological Inst.; Legutke, Stephanie [Max Planck Inst. for Meteorology, Hamburg (Germany); Kwon, Won-Tae [Meteorological Research Inst., Seoul (Korea, Republic of)

2005-08-01

The internal variability in a 1000-yr control simulation with the coupled atmosphere/ocean global climate model ECHO-G is analysed using near-surface temperature, precipitation and mean sea level pressure variables, and is compared with observations and other coupled climate model simulations. ECHO-G requires annual mean flux adjustments for heat and freshwater in order to simulate no significant climate drift for 1000 yr, but no flux adjustments for momentum. The ECHO-G control run captures well most aspects of the observed seasonal and annual climatology and of the interannual to decadal variability of the three variables. Model biases are very close to those in ECHAM4 (atmospheric component of ECHO-G) stand-alone integrations with prescribed observed sea surface temperature. A trend comparison between observed and modelled near-surface temperatures shows that the observed near-surface global warming is larger than internal variability produced by ECHO-G, supporting previous studies. The simulated global mean near-surface temperatures, however, show a 2-yr spectral peak which is linked with a strong biennial bias of energy in the El Nino Southern Oscillation signal. Consequently, the interannual variability (39 yr) is underestimated.

Climatological Distributions of pH, pCO2, Total CO2, Alkalinity, and CaCO3 Saturation in the Global Surface Ocean (NCEI accession 01645680) (NCEI Accession 0164568)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Climatological mean monthly distributions of pH in the total H+ scale, total CO2 concentration (TCO2), and the degree of CaCO3 saturation for the global surface...

LBA Regional Monthly Climatology for the 20th Century (New et al.)

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: This data set is a subset of "Global Monthly Climatology for the 20th Century (New et al.)" (2000a). This subset characterizes mean monthly surface climate...

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...

A Spatio-Temporal Analysis of Heatwave Climatology in Three Major US Cities

Science.gov (United States)

Hulley, G. C.; Malakar, N.

2016-12-01

Heatwaves are one form of severe weather expected to become worse under a warming planet. The impacts of severe heatwaves, particularly in urban areas, can have detrimental and often deadly consequences across key socio-economic urban sectors.These effects are exacerbated by the urban heat island effect, and an overall increase in the number of city dwellers during the 21st century. For example it is projected that nearly 80% of the world's population will live in cities by 2025. In this study we use a combination of in situ and remote sensing measured surface temperatures to investigate the spatio-temporal variations of heatwaves in three major U.S. cities; Los Angeles, Chicago, and Washington D.C. Air temperature data from the NCDC US COOP network stations are used to first detect severe heatwave events using two new excess heat indices, and secondly to assess climatological changes in heatwave frequency, duration, and intensity since the 1950's. For example, in Los Angeles there has been a steady increase in the duration and frequency of heatwaves, while nighttime heatwave temperatures have shown a rapid warming since the start of the 21st century. The second part of the study uses a new land surface temperature product (MOD21) derived from the MODIS Aqua sensor to analyze the spatial variations of heatwave temperatures within urban environments, as a goal to help better understand and predict what areas may be more vulnerable to the effects of extreme temperatures in an effort to advise local councils on effective adaption and mitigation techniques.

LBA Regional Monthly Climatology for the 20th Century (New et al.)

Data.gov (United States)

National Aeronautics and Space Administration — This data set is a subset of "Global Monthly Climatology for the 20th Century (New et al.)" (2000a). This subset characterizes mean monthly surface climate over the...

Predictability of rainfall and teleconnections patterns influencing on Southwest Europe from sea surfaces temperatures

Science.gov (United States)

Lorenzo, M. N.; Iglesias, I.; Taboada, J. J.; Gómez-Gesteira, M.; Ramos, A. M.

2009-04-01

which could be related with the Monsoon. Another area with high correlation is Equatorial Pacific Ocean, the area related with the ENSO phenomenon. These SSTAs could be used to forecast rainfall anomalies in spring season in the area of NW Iberian Peninsula. Results show that La Niña years almost always announces dry spring in NW Iberian Peninsula. Nevertheless, El Niño years do not preclude the appearance of wet spring. Because of the progress that has been made in its prediction, the relation between ENSO and climate in NW Iberian Peninsula is of interest with respect to potential seasonal predictability and the results can be extended to the south west of Europe. [1] Lorenzo, M.N. and J. J. Taboada (2005). Influences of atmospheric variability on freshwater input in Galician Rías in winter. Journal of Atmospheric and Ocean Science Vol 10, No 4, 377-387. [2] Lorenzo, M.N. I. Iglesias, J.J. Taboada and M. Gómez-Gesteira. Relationship between monthly rainfall in NW Iberian Peninsula and North Atlantic sea surface temperature. International Journal of Climatology. (Submitted to International Journal of Climatology). [3] Philips, I.D. and J. Thorpe (2006): Icelandic precipitation-North Atlantic sea-surface temperature associations. International Journal of Climatology 26: 1201-1221.

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

International Nuclear Information System (INIS)

Vose, R.S.; Schmoyer, R.L.; Peterson, T.C.; Steurer, P.M.; Heim, R.R. Jr.; Karl, T.R.; Eischeid, J.K.

1992-01-01

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)

Empirical Mode Decomposition on the sphere: application to the spatial scales of surface temperature variations

Directory of Open Access Journals (Sweden)

N. Fauchereau

2008-06-01

Full Text Available Empirical Mode Decomposition (EMD is applied here in two dimensions over the sphere to demonstrate its potential as a data-adaptive method of separating the different scales of spatial variability in a geophysical (climatological/meteorological field. After a brief description of the basics of the EMD in 1 then 2 dimensions, the principles of its application on the sphere are explained, in particular via the use of a zonal equal area partitioning. EMD is first applied to an artificial dataset, demonstrating its capability in extracting the different (known scales embedded in the field. The decomposition is then applied to a global mean surface temperature dataset, and we show qualitatively that it extracts successively larger scales of temperature variations related, for example, to topographic and large-scale, solar radiation forcing. We propose that EMD can be used as a global data-adaptive filter, which will be useful in analysing geophysical phenomena that arise as the result of forcings at multiple spatial scales.

Temperature sensitivity to the land-surface model in MM5 climate simulations over the Iberian Peninsula

Energy Technology Data Exchange (ETDEWEB)

Jerez, Sonia; Montavez, Juan P.; Gomez-Navarro, Juan J.; Jimenez-Guerrero, Pedro [Dept. de Fisica, Univ. de Murcia (Spain); Jimenez, Jose M.; Gonzalez-Rouco, Jesus F. [Dept. de Astrofisica y CC. de la Atmosfera, Univ. Complutense de Madrid (Spain)

2010-06-15

Three different Land Surface Models have been used in three high resolution climate simulations performed with the mesoscale model MM5 over the Iberian Peninsula. The main difference among them lies in the soil moisture treatment, which is dynamically modelled by only two of them (Noah and Pleim and Xiu models), while in the simplest model (Simple Five-Layers) it is fixed to climatological values. The simulated period covers 1958-2002, using the ERA40 reanalysis data as driving conditions. Focusing on near-surface air temperature, this work evaluates the skill of each simulation in reproducing mean values and temporal variability, by comparing the simulations with observed temperature series. When the simplest simulation was analyzed, the greatest discrepances were observed for the summer season, when both, the mean values and the temporal variability of the temperature series, were badly underestimated. These weaknesses are largely overcome in the other two simulations (performed by coupling a more advanced soil model to MM5), and there was greater concordance between the simulated and observed spatial patterns. The influence of a dynamic soil moisture parameterization and, therefore, a more realistic simulation of the latent and sensible heat fluxes between the land and the atmosphere, helps to explain these results. (orig.)

Retrievals of Surface Air Temperature Using Multiple Satellite Data Combinations over Complex Terrain in the Korean Peninsula

Science.gov (United States)

Jang, K.; Won, M.; Yoon, S.; Lim, J.

2016-12-01

Surface air temperature (Tair) is a fundamental factor for terrestrial environments and plays a major role in the fields of applied meteorology, climatology, and ecology. The satellite remotely sensed data offers the opportunity to estimate Tair on the earth's surface with high spatial and temporal resolutions. The Moderate Resolution Imaging Spectroradiometer (MODIS) provides effective Tair retrievals although restricted to clear sky condition. MODIS Tair over complex terrain can result in significant retrieval errors due to the retrieval height mismatch to the elevation of local weather stations. In this study, we propose the methodology to estimate Tair over complex terrain for all sky conditions using multiple satellite data fusion based on the pixel-wise regression method. The combination of synergistic information from MODIS Tair and the brightness temperature (Tb) retrievals at 37 GHz frequency from the satellite microwave sensor were used for analysis. The air temperature lapse rate was applied to estimate the near-surface Tair considering the complex terrain such as mountainous regions. The retrieval results produced from this study showed a good agreement (RMSE Administration (KMA). The gaps in the MODIS Tair data due to cloud contamination were successfully filled using the proposed method which yielded similar accuracy as retrievals of clear sky. The results of this study indicate that the satellite data fusion can continuously produce Tair retrievals with reasonable accuracy and that the application of the temperature lapse rate can lead to improvement of the reliability over complex terrains such as the Korean Peninsula.

Extratropical Influence of Sea Surface Temperature and Wind on Water Recycling Rate Over Oceans and Coastal Lands

Science.gov (United States)

Hu, Hua; Liu, W. Timothy

1999-01-01

Water vapor and precipitation are two important parameters confining the hydrological cycle in the atmosphere and over the ocean surface. In the extratropical areas, due to variations of midlatitude storm tracks and subtropical jetstreams, water vapor and precipitation have large variability. Recently, a concept of water recycling rate defined previously by Chahine et al. (GEWEX NEWS, August, 1997) has drawn increasing attention. The recycling rate of moisture is calculated as the ratio of precipitation to total precipitable water (its inverse is the water residence time). In this paper, using multi-sensor spacebased measurements we will study the role of sea surface temperature and ocean surface wind in determining the water recycling rate over oceans and coastal lands. Response of water recycling rate in midlatitudes to the El Nino event will also be discussed. Sea surface temperature data are derived from satellite observations from the Advanced Very High Resolution Radiometer (AVHRR) blended with in situ measurements, available for the period 1982-1998. Global sea surface wind observations are obtained from spaceborne scatterometers aboard on the European Remote-Sensing Satellite (ERS1 and 2), available for the period 1991-1998. Global total precipitable water provided by the NASA Water Vapor Project (NVAP) is available for the period 1988-1995. Global monthly mean precipitation provided by the Global Precipitation Climatology Project (GPCP) is available for the period 1987-1998.

Sensitivity of the sea ice concentration over the Kara-Barents Sea in autumn to the winter temperature variability over East Asia

Science.gov (United States)

Cho, K. H.; Chang, E. C.

2017-12-01

In this study, we performed sensitivity experiments by utilizing the Global/Regional Integrated Model system with different conditions of the sea ice concentration over the Kara-Barents (KB) Sea in autumn, which can affect winter temperature variability over East Asia. Prescribed sea ice conditions are 1) climatological autumn sea ice concentration obtained from 1982 to 2016, 2) reduced autumn sea ice concentration by 50% of the climatology, and 3) increased autumn sea ice concentration by 50% of climatology. Differently prescribed sea ice concentration changes surface albedo, which affects surface heat fluxes and near-surface air temperature. The reduced (increased) sea ice concentration over the KB sea increases (decreases) near-surface air temperature that leads the lower (higher) sea level pressure in autumn. These patterns are maintained from autumn to winter season. Furthermore, it is shown that the different sea ice concentration over the KB sea has remote effects on the sea level pressure patterns over the East Asian region. The lower (higher) sea level pressure over the KB sea by the locally decreased (increased) ice concentration is related to the higher (lower) pressure pattern over the Siberian region, which induces strengthened (weakened) cold advection over the East Asian region. From these sensitivity experiments it is clarified that the decreased (increased) sea ice concentration over the KB sea in autumn can lead the colder (warmer) surface air temperature over East Asia in winter.

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

A North American regional reanalysis climatology of the Haines Index

Science.gov (United States)

Wei Lu; Joseph J. (Jay) Charney; Sharon Zhong; Xindi Bian; Shuhua. Liu

2011-01-01

A warm-season (May through October) Haines Index climatology is derived using 32-km regional reanalysis temperature and humidity data from 1980 to 2007. We compute lapse rates, dewpoint depressions, Haines Index factors A and B, and values for each of the low-, mid- and high-elevation variants of the Haines Index. Statistical techniques are used to investigate the...

Climate reconstruction from borehole temperatures influenced by groundwater flow

Science.gov (United States)

Kurylyk, B.; Irvine, D. J.; Tang, W.; Carey, S. K.; Ferguson, G. A. G.; Beltrami, H.; Bense, V.; McKenzie, J. M.; Taniguchi, M.

2017-12-01

Borehole climatology offers advantages over other climate reconstruction methods because further calibration steps are not required and heat is a ubiquitous subsurface property that can be measured from terrestrial boreholes. The basic theory underlying borehole climatology is that past surface air temperature signals are reflected in the ground surface temperature history and archived in subsurface temperature-depth profiles. High frequency surface temperature signals are attenuated in the shallow subsurface, whereas low frequency signals can be propagated to great depths. A limitation of analytical techniques to reconstruct climate signals from temperature profiles is that they generally require that heat flow be limited to conduction. Advection due to groundwater flow can thermally `contaminate' boreholes and result in temperature profiles being rejected for regional climate reconstructions. Although groundwater flow and climate change can result in contrasting or superimposed thermal disturbances, groundwater flow will not typically remove climate change signals in a subsurface thermal profile. Thus, climate reconstruction is still possible in the presence of groundwater flow if heat advection is accommodated in the conceptual and mathematical models. In this study, we derive a new analytical solution for reconstructing surface temperature history from borehole thermal profiles influenced by vertical groundwater flow. The boundary condition for the solution is composed of any number of sequential `ramps', i.e. periods with linear warming or cooling rates, during the instrumented and pre-observational periods. The boundary condition generation and analytical temperature modeling is conducted in a simple computer program. The method is applied to reconstruct climate in Winnipeg, Canada and Tokyo, Japan using temperature profiles recorded in hydrogeologically active environments. The results demonstrate that thermal disturbances due to groundwater flow and climate

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.

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

International Nuclear Information System (INIS)

Aslan, Z.

2004-01-01

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

Temporal variations of NDVI and correlations between NDVI and hydro-climatological variables at Lake Baiyangdian, China.

Science.gov (United States)

Wang, Fei; Wang, Xuan; Zhao, Ying; Yang, Zhifeng

2014-09-01

In this paper, correlations between vegetation dynamics (represented by the normalized difference vegetation index (NDVI)) and hydro-climatological factors were systematically studied in Lake Baiyangdian during the period from April 1998 to July 2008. Six hydro-climatological variables including lake volume, water level, air temperature, precipitation, evaporation, and sunshine duration were used, as well as extracted NDVI series data representing vegetation dynamics. Mann-Kendall tests were used to detect trends in NDVI and hydro-climatological variation, and a Bayesian information criterion method was used to detect their abrupt changes. A redundancy analysis (RDA) was used to determine the major hydro-climatological factors contributing to NDVI variation at monthly, seasonal, and yearly scales. The results were as follows: (1) the trend analysis revealed that only sunshine duration significantly increased over the study period, with an inter-annual increase of 3.6 h/year (p NDVI trends were negligible; (2) the abrupt change detection showed that a major hydro-climatological change occurred in 2004, when abrupt changes occurred in lake volume, water level, and sunlight duration; and (3) the RDA showed that evaporation and temperature were highly correlated with monthly changes in NDVI. At larger time scales, however, water level and lake volume gradually became more important than evaporation and precipitation in terms of their influence on NDVI. These results suggest that water availability is the most important factor in vegetation restoration. In this paper, we recommend a practical strategy for lake ecosystem restoration that takes into account changes in NDVI.

The climatology of the Red Sea - part 2: the waves

KAUST Repository

Langodan, Sabique; Cavaleri, Luigi; Pomaro, Angela; Vishwanadhapalli, Yesubabu; Bertotti, Luciana; Hoteit, Ibrahim

2017-01-01

The wave climatology of the Red Sea is described based on a 30-year hindcast generated using WAVEWATCH III configured on a 5-km resolution grid and forced by Red Sea reanalysis surface winds from the advanced Weather Research and Forecasting model

Sea surface stability parameters

International Nuclear Information System (INIS)

Weber, A.H.; Suich, J.E.

1978-01-01

A number of studies dealing with climatology of the Northwest Atlantic Ocean have been published in the last ten years. These published studies have dealt with directly measured meteorological parameters, e.g., wind speed, temperature, etc. This information has been useful because of the increased focus on the near coastal zone where man's activities are increasing in magnitude and scope, e.g., offshore power plants, petroleum production, and the subsequent environmental impacts of these activities. Atmospheric transport of passive or nonpassive material is significantly influenced by the turbulence structure of the atmosphere in the region of the atmosphere-ocean interface. This research entails identification of the suitability of standard atmospheric stability parameters which can be used to determine turbulence structure; the calculation of these parameters for the near-shore and continental shelf regions of the U.S. east coast from Cape Hatteras to Miami, Florida; and the preparation of a climatology of these parameters. In addition, a climatology for average surface stress for the same geographical region is being prepared

Estimation of bare soil surface temperature from air temperature and ...

African Journals Online (AJOL)

Soil surface temperature has critical influence on climate, agricultural and hydrological activities since it serves as a good indicator of the energy budget of the earth's surface. Two empirical models for estimating soil surface temperature from air temperature and soil depth temperature were developed. The coefficient of ...

Direct and semi-direct effects of aerosol climatologies on long-term climate simulations over Europe

Science.gov (United States)

Schultze, Markus; Rockel, Burkhardt

2017-08-01

This study compares the direct and semi-direct aerosol effects of different annual cycles of tropospheric aerosol loads for Europe from 1950 to 2009 using the regional climate model COSMO-CLM, which is laterally forced by reanalysis data and run using prescribed, climatological aerosol optical properties. These properties differ with respect to the analysis strategy and the time window, and are then used for the same multi-decadal period. Five simulations with different aerosol loads and one control simulation without any tropospheric aerosols are integrated and compared. Two common limitations of our simulation strategy, to fully assess direct and semi-direct aerosol effects, are the applied observed sea surface temperatures and sea ice conditions, and the lack of short-term variations in the aerosol load. Nevertheless, the impact of different aerosol climatologies on common regional climate model simulations can be assessed. The results of all aerosol-including simulations show a distinct reduction in solar irradiance at the surface compared with that in the control simulation. This reduction is strongest in the summer season and is balanced primarily by a weakening of turbulent heat fluxes and to a lesser extent by a decrease in longwave emissions. Consequently, the seasonal mean surface cooling is modest. The temperature profile responses are characterized by a shallow near-surface cooling and a dominant warming up to the mid-troposphere caused by aerosol absorption. The resulting stabilization of stratification leads to reduced cloud cover and less precipitation. A decrease in cloud water and ice content over Central Europe in summer possibly reinforce aerosol absorption and thus strengthen the vertical warming. The resulting radiative forcings are positive. The robustness of the results was demonstrated by performing a simulation with very strong aerosol forcing, which lead to qualitatively similar results. A distinct added value over the default aerosol

Spatial patterns of sea surface temperature influences on East African precipitation as revealed by empirical orthogonal teleconnections

Directory of Open Access Journals (Sweden)

Tim eAppelhans

2016-02-01

Full Text Available East Africa is characterized by a rather dry annual precipitation climatology with two distinct rainy seasons. In order to investigate sea surface temperature driven precipitation anomalies for the region we use the algorithm of empirical orthogonal teleconnection analysis as a data mining tool. We investigate the entire East African domain as well as 5 smaller sub-regions mainly located in areas of mountainous terrain. In searching for influential sea surface temperature patterns we do not focus any particular season or oceanic region. Furthermore, we investigate different time lags from zero to twelve months. The strongest influence is identified for the immediate (i.e. non-lagged influences of the Indian Ocean in close vicinity to the East African coast. None of the most important modes are located in the tropical Pacific Ocean, though the region is sometimes coupled with the Indian Ocean basin. Furthermore, we identify a region in the southern Indian Ocean around the Kerguelen Plateau which has not yet been reported in the literature with regard to precipitation modulation in East Africa. Finally, it is observed that not all regions in East Africa are equally influenced by the identified patterns.

Near-surface temperature inversion during summer at Summit, Greenland, and its relation to MODIS-derived surface temperatures

Science.gov (United States)

Adolph, Alden C.; Albert, Mary R.; Hall, Dorothy K.

2018-03-01

As rapid warming of the Arctic occurs, it is imperative that climate indicators such as temperature be monitored over large areas to understand and predict the effects of climate changes. Temperatures are traditionally tracked using in situ 2 m air temperatures and can also be assessed using remote sensing techniques. Remote sensing is especially valuable over the Greenland Ice Sheet, where few ground-based air temperature measurements exist. Because of the presence of surface-based temperature inversions in ice-covered areas, differences between 2 m air temperature and the temperature of the actual snow surface (referred to as skin temperature) can be significant and are particularly relevant when considering validation and application of remote sensing temperature data. We present results from a field campaign extending from 8 June to 18 July 2015, near Summit Station in Greenland, to study surface temperature using the following measurements: skin temperature measured by an infrared (IR) sensor, 2 m air temperature measured by a National Oceanic and Atmospheric Administration (NOAA) meteorological station, and a Moderate Resolution Imaging Spectroradiometer (MODIS) surface temperature product. Our data indicate that 2 m air temperature is often significantly higher than snow skin temperature measured in situ, and this finding may account for apparent biases in previous studies of MODIS products that used 2 m air temperature for validation. This inversion is present during our study period when incoming solar radiation and wind speed are both low. As compared to our in situ IR skin temperature measurements, after additional cloud masking, the MOD/MYD11 Collection 6 surface temperature standard product has an RMSE of 1.0 °C and a mean bias of -0.4 °C, spanning a range of temperatures from -35 to -5 °C (RMSE = 1.6 °C and mean bias = -0.7 °C prior to cloud masking). For our study area and time series, MODIS surface temperature products agree with skin surface

A Smart Climatology of Evaporation Duct Height and Surface Radar Propagation in the Indian Ocean

National Research Council Canada - National Science Library

Twigg, Katherine L

2007-01-01

.... We have used existing, civilian, dynamically balanced reanalysis data, for 1970 to 2006, and a state-of-the-art ED model, to produce a spatially and temporally refined EDH climatology for the Indian Ocean (10) and nearby seas...

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...

Enhancing Extreme Heat Health-Related Intervention and Preparedness Activities Using Remote Sensing Analysis of Daily Surface Temperature, Surface Observation Networks and Ecmwf Reanalysis

Science.gov (United States)

Garcia, R. L.; Booth, J.; Hondula, D.; Ross, K. W.; Stuyvesant, A.; Alm, G.; Baghel, E.

2015-12-01

Extreme heat causes more human fatalities in the United States than any other natural disaster, elevating the concern of heat-related mortality. Maricopa County Arizona is known for its high heat index and its sprawling metropolitan complex which makes this region a perfect candidate for human health research. Individuals at higher risk are unequally spatially distributed, leaving the poor, homeless, non-native English speakers, elderly, and the socially isolated vulnerable to heat events. The Arizona Department of Health Services, Arizona State University and NASA DEVELOP LaRC are working to establish a more effective method of placing hydration and cooling centers in addition to enhancing the heat warning system to aid those with the highest exposure. Using NASA's Earth Observation Systems from Aqua and Terra satellites, the daily spatial variability within the UHI was quantified over the summer heat seasons from 2005 - 2014, effectively establishing a remotely sensed surface temperature climatology for the county. A series of One-way Analysis of Variance revealed significant differences between daily surface temperature averages of the top 30% of census tracts within the study period. Furthermore, synoptic upper tropospheric circulation patterns were classified to relate surface weather types and heat index. The surface weather observation networks were also reviewed for analyzing the veracity of the other methods. The results provide detailed information regarding nuances within the UHI effect and will allow pertinent recommendations regarding the health department's adaptive capacity. They also hold essential components for future policy decision-making regarding appropriate locations for cooling centers and efficient warning systems.

A Multiscale Surface Water Temperature Data Acquisition Platform: Tests on Lake Geneva, Switzerland

Science.gov (United States)

Barry, D. A.; Irani Rahaghi, A.; Lemmin, U.; Riffler, M.; Wunderle, S.

2015-12-01

An improved understanding of surface transport processes is necessary to predict sediment, pollutant and phytoplankton patterns in large lakes. Lake surface water temperature (LSWT), which varies in space and time, reflects meteorological and climatological forcing more than any other physical lake parameter. There are different data sources for LSWT mapping, including remote sensing and in situ measurements. Satellite data can be suitable for detecting large-scale thermal patterns, but not meso- or small scale processes. Lake surface thermography, investigated in this study, has finer resolution compared to satellite images. Thermography at the meso-scale provides the ability to ground-truth satellite imagery over scales of one to several satellite image pixels. On the other hand, thermography data can be used as a control in schemes to upscale local measurements that account for surface energy fluxes and the vertical energy budget. Independently, since such data can be collected at high frequency, they can be also useful in capturing changes in the surface signatures of meso-scale eddies and thus to quantify mixing processes. In the present study, we report results from a Balloon Launched Imaging and Monitoring Platform (BLIMP), which was developed in order to measure the LSWT at meso-scale. The BLIMP consists of a small balloon that is tethered to a boat and equipped with thermal and RGB cameras, as well as other instrumentation for location and communication. Several deployments were carried out on Lake Geneva. In a typical deployment, the BLIMP is towed by a boat, and collects high frequency data from different heights (i.e., spatial resolutions) and locations. Simultaneous ground-truthing of the BLIMP data is achieved using an autonomous craft that collects a variety of data, including in situ surface/near surface temperatures, radiation and meteorological data in the area covered by the BLIMP images. With suitable scaling, our results show good consistency

The Impact of Wet Soil and Canopy Temperatures on Daytime Boundary-Layer Growth.

Science.gov (United States)

Segal, M.; Garratt, J. R.; Kallos, G.; Pielke, R. A.

1989-12-01

The impact of very wet soil and canopy temperatures on the surface sensible heat flux, and on related daytime boundary-layer properties is evaluated. For very wet soils, two winter situations are considered, related to significant changes in soil surface temperature: (1) due to weather perturbations at a given location, and (2) due to the climatological north-south temperature gradient. Analyses and scaling of the various boundary-layer properties, and soil surface fluxes affecting the sensible beat flux, have been made; related evaluations show that changes in the sensible heat flux at a given location by a factor of 2 to 3 due to temperature changes related to weather perturbations is not uncommon. These changes result in significant alterations in the boundary-layer depth; in the atmospheric boundary-layer warming; and in the break-up time of the nocturnal surface temperature inversion. Investigation of the impact of the winter latitudinal temperature gradient on the above characteristics indicated that the relative increase in very wet soil sensible heat flux, due to the climatological reduction in the surface temperature in northern latitudes, moderates to some extent its reduction due to the corresponding decrease in solar radiation. Numerical model simulations confirmed these analytical evaluations.In addition, the impact of synoptic temperature perturbations during the transition seasons (fall and spring) on canopy sensible heal fluxes, and the related boundary-layer characteristics mentioned above, was evaluated. Analogous features to those found for very wet soil surfaces occurred also for the canopy situations. Likewise, evaluations were also carried out to explore the impact of high midlatitude foreste areas on the boundary-layer characteristics during the winter as compared to those during the summer. Similar impacts were found in both seasons, regardless of the substantial difference in the daily total solar radiation.

A Wildfire-relevant climatology of the convective environment of the United States

Science.gov (United States)

Brian E. Potter; Matthew A. Anaya

2015-01-01

Convective instability can influence the behaviour of large wildfires. Because wildfires modify the temperature and moisture of air in their plumes, instability calculations using ambient conditions may not accurately represent convective potential for some fire plumes. This study used the North American Regional Reanalysis to develop a climatology of the convective...

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 areas...

FLDAS Noah Land Surface Model L4 Monthly Climatology 0.1 x 0.1 degree for Eastern Africa (MERRA-2 and CHIRPS) V001 (FLDAS_NOAH01_C_EA_MC) at GES DISC

Data.gov (United States)

National Aeronautics and Space Administration — The monthly climatology data set contains a series of land surface parameters simulated from the Noah 3.3 model in the Famine Early Warning Systems Network (FEWS...

Near-surface temperature inversion during summer at Summit, Greenland, and its relation to MODIS-derived surface temperatures

Directory of Open Access Journals (Sweden)

A. C. Adolph

2018-03-01

Full Text Available As rapid warming of the Arctic occurs, it is imperative that climate indicators such as temperature be monitored over large areas to understand and predict the effects of climate changes. Temperatures are traditionally tracked using in situ 2 m air temperatures and can also be assessed using remote sensing techniques. Remote sensing is especially valuable over the Greenland Ice Sheet, where few ground-based air temperature measurements exist. Because of the presence of surface-based temperature inversions in ice-covered areas, differences between 2 m air temperature and the temperature of the actual snow surface (referred to as skin temperature can be significant and are particularly relevant when considering validation and application of remote sensing temperature data. We present results from a field campaign extending from 8 June to 18 July 2015, near Summit Station in Greenland, to study surface temperature using the following measurements: skin temperature measured by an infrared (IR sensor, 2 m air temperature measured by a National Oceanic and Atmospheric Administration (NOAA meteorological station, and a Moderate Resolution Imaging Spectroradiometer (MODIS surface temperature product. Our data indicate that 2 m air temperature is often significantly higher than snow skin temperature measured in situ, and this finding may account for apparent biases in previous studies of MODIS products that used 2 m air temperature for validation. This inversion is present during our study period when incoming solar radiation and wind speed are both low. As compared to our in situ IR skin temperature measurements, after additional cloud masking, the MOD/MYD11 Collection 6 surface temperature standard product has an RMSE of 1.0 °C and a mean bias of −0.4 °C, spanning a range of temperatures from −35 to −5 °C (RMSE  =  1.6 °C and mean bias  =  −0.7 °C prior to cloud masking. For our study area and time series

Winter-regime surface heat loss from heated streams

International Nuclear Information System (INIS)

Paily, P.P.; Macagno, E.O.; Kennedy, J.F.

1974-01-01

Evaluation of the rate of surface heat exchange between the water and air is a significant factor in any study of the thermal response of heated streams to heat inputs. Existing methods to determine the amount of heat transfer across the water surface are surveyed, and the different formulas developed for determining the heat exchange components are compiled. Heat-transfer models that have been proposed in the literature are reviewed, and a new linearized model for determining the rate of surface heat exchange is proposed. Generalized relations between the major climatological factors and the coefficients of the linearized heat-loss rate are established by multiple-regression analysis. The analysis is limited to cold-period conditions, in the sense that air temperatures below the freezing point of water only are considered in developing the regression equations. A computer program, using FORTRAN, is presented which enables the computation of the coefficients appearing in the linearized heat-loss rate for all combinations of the various climatological factors

Sensitivity of Horn of Africa Rainfall to Regional Sea Surface Temperature Forcing

Directory of Open Access Journals (Sweden)

Zewdu T. Segele

2015-05-01

Full Text Available The Abdus Salam International Center for Theoretical Physics (ICTP version 4.4 Regional Climate Model (RegCM4 is used to investigate the rainfall response to cooler/warmer sea surface temperature anomaly (SSTA forcing in the Indian and Atlantic Oceans. The effect of SSTA forcing in a specific ocean basin is identified by ensemble, averaging 10 individual simulations in which a constant or linearly zonally varying SSTA is prescribed in individual basins while specifying the 1971–2000 monthly varying climatological sea surface temperature (SST across the remaining model domain. The nonlinear rainfall response to SSTA amplitude also is investigated by separately specifying +1K, +2K, and +4K SSTA forcing in the Atlantic and Indian Oceans. The simulation results show that warm SSTs over the entire Indian Ocean produce drier conditions across the larger Blue Nile catchment, whereas warming ≥ +2K generates large positive rainfall anomalies exceeding 10 mm·day−1 over drought prone regions of Northeastern Ethiopia. However, the June–September rainy season tends to be wetter (drier when the SST warming (cooling is limited to either the Northern or Southern Indian Ocean. Wet rainy seasons generally are characterized by deepening of the monsoon trough, east of 40°E, intensification of the Mascarene high, strengthening of the Somali low level jet and the tropical easterly jet, enhanced zonal and meridional vertically integrated moisture fluxes, and steeply vertically decreasing moist static energy. The opposite conditions hold for dry monsoon seasons.

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...

Estimation of daily minimum land surface air temperature using MODIS data in southern Iran

Science.gov (United States)

Didari, Shohreh; Norouzi, Hamidreza; Zand-Parsa, Shahrokh; Khanbilvardi, Reza

2017-11-01

Land surface air temperature (LSAT) is a key variable in agricultural, climatological, hydrological, and environmental studies. Many of their processes are affected by LSAT at about 5 cm from the ground surface (LSAT5cm). Most of the previous studies tried to find statistical models to estimate LSAT at 2 m height (LSAT2m) which is considered as a standardized height, and there is not enough study for LSAT5cm estimation models. Accurate measurements of LSAT5cm are generally acquired from meteorological stations, which are sparse in remote areas. Nonetheless, remote sensing data by providing rather extensive spatial coverage can complement the spatiotemporal shortcomings of meteorological stations. The main objective of this study was to find a statistical model from the previous day to accurately estimate spatial daily minimum LSAT5cm, which is very important in agricultural frost, in Fars province in southern Iran. Land surface temperature (LST) data were obtained using the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Aqua and Terra satellites at daytime and nighttime periods with normalized difference vegetation index (NDVI) data. These data along with geometric temperature and elevation information were used in a stepwise linear model to estimate minimum LSAT5cm during 2003-2011. The results revealed that utilization of MODIS Aqua nighttime data of previous day provides the most applicable and accurate model. According to the validation results, the accuracy of the proposed model was suitable during 2012 (root mean square difference ( RMSD) = 3.07 °C, {R}_{adj}^2 = 87 %). The model underestimated (overestimated) high (low) minimum LSAT5cm. The accuracy of estimation in the winter time was found to be lower than the other seasons ( RMSD = 3.55 °C), and in summer and winter, the errors were larger than in the remaining seasons.

Evaluation of Flat Surface Temperature Probes

Science.gov (United States)

Beges, G.; Rudman, M.; Drnovsek, J.

2011-01-01

The objective of this paper is elaboration of elements related to metrological analysis in the field of surface temperature measurement. Surface temperature measurements are applicable in many fields. As examples, safety testing of electrical appliances and a pharmaceutical production line represent case studies for surface temperature measurements. In both cases correctness of the result of the surface temperature has an influence on final product safety and quality and thus conformity with specifications. This paper deals with the differences of flat surface temperature probes in measuring the surface temperature. For the purpose of safety testing of electrical appliances, surface temperature measurements are very important for safety of the user. General requirements are presented in European standards, which support requirements in European directives, e.g., European Low Voltage Directive 2006/95/EC and pharmaceutical requirements, which are introduced in official state legislation. This paper introduces a comparison of temperature measurements of an attached thermocouple on the measured surface and measurement with flat surface temperature probes. As a heat generator, a so called temperature artifact is used. It consists of an aluminum plate with an incorporated electrical heating element with very good temperature stability in the central part. The probes and thermocouple were applied with different forces to the surface in horizontal and vertical positions. The reference temperature was measured by a J-type fine-wire (0.2 mm) thermocouple. Two probes were homemade according to requirements in the European standard EN 60335-2-9/A12, one with a fine-wire (0.2 mm) thermocouple and one with 0.5mm of thermocouple wire diameter. Additional commercially available probes were compared. Differences between probes due to thermal conditions caused by application of the probe were found. Therefore, it can happen that measurements are performed with improper equipment or

Climatology and seasonality of upper ocean salinity: a three-dimensional view from argo floats

Science.gov (United States)

Chen, Ge; Peng, Lin; Ma, Chunyong

2018-03-01

Primarily due to the constraints of observation technologies (both field and satellite measurements), our understanding of ocean salinity is much less mature compared to ocean temperature. As a result, the characterizations of the two most important properties of the ocean are unfortunately out of step: the former is one generation behind the latter in terms of data availability and applicability. This situation has been substantially changed with the advent of the Argo floats which measure the two variables simultaneously on a global scale since early this century. The first decade of Argo-acquired salinity data are analyzed here in the context of climatology and seasonality, yielding the following main findings for the global upper oceans. First, the six well-defined "salty pools" observed around ±20° in each hemisphere of the Pacific, Atlantic and Indian Oceans are found to tilt westward vertically from the sea surface to about 600 m depth, forming six saline cores within the subsurface oceans. Second, while potential temperature climatology decreases monotonically to the bottom in most places of the ocean, the vertical distribution of salinity can be classified into two categories: A double-halocline type forming immediately above and below the local salinity maximum around 100-150 m depths in the tropical and subtropical oceans, and a single halocline type existing at about 100 m depth in the extratropical oceans. Third, in contrast to the midlatitude dominance for temperature, seasonal variability of salinity in the oceanic mixed layer has a clear tropical dominance. Meanwhile, it is found that a two-mode structure with annual and semiannual periodicities can effectively penetrate through the upper ocean into a depth of 2000 m. Fourth, signature of Rossby waves is identified in the annual phase map of ocean salinity within 200-600 m depths in the tropical oceans, revealing a strongly co-varying nature of ocean temperature and salinity at specific depths

Climatological variability in regional air pollution

International Nuclear Information System (INIS)

Shannon, J.D.; Trexler, E.C. Jr.

1995-01-01

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

Temperature dependence of nuclear surface properties

International Nuclear Information System (INIS)

Campi, X.; Stringari, S.

1982-01-01

Thermal properties of nuclear surface are investigated in a semi-infinite medium. Explicit analytical expression are given for the temperature dependence of surface thickness, surface energy and surface free energy. In this model the temperature effects depend critically on the nuclear incompressibility and on the shape of the effective mass at the surface. To illustrate the relevance of these effects we made an estimate of the temperature dependence of the fission barrier height. (orig.)

The Adaptive Ecosystem Climatology (AEC): Design and Development

Science.gov (United States)

deRada, S.; Penta, B.; McCarthy, S.; Gould, R. W., Jr.

2016-02-01

The concept of ecosystem-based management (EBM), recently introduced to rectify the shortcomings of single-species management policies, has been widely accepted as a basis for the conservation and management of natural resources. In line with NOAA's Integrated Ecosystem Assessment (IEA) Program, EBM is an integrated approach that considers the entire ecosystem and the interactions among species rather than focusing on individual components. This integrative approach relies on heterogeneous data, physical as well as biogeochemical data, among many others. Relative to physical data, however, marine biogeochemical records, also critical in IEA and EBM, are still lacking, both in terms of mature models and in terms of observational data availability. TheAdaptive Ecosystem Climatology (AEC) was conceived as a novel approach to address these limitations, mitigating the shortcomings of the individual components and combining their strengths to enhance decision-making activities. AEC is designed on the concept that a high-frequency climatology can be used as a baseline into which available observational data can be ingested to produce a higher accuracy product. In the absence of observations, the climatology acts as a best estimate. AEC was developed using a long-term simulation of a coupled biophysical numerical model configured for the Gulf of Mexico. Using the model results, we constructed a three-dimensional, dynamically balanced, gridded, static climatology for each calendar day. Using this `static' climatology as a background `first guess', observations from a particular date are ingested via optimal interpolation to `nudge' the climatology toward current conditions, thus providing representative fields for that date (adaptive climatology). With this adaptive approach, AEC can support a variety of EBM objectives, from fisheries, to resource management, to coastal resilience.

Differential temperature preferences and thresholds among summer campers in Ontario's southern provincial parks: a Canadian case study in tourism climatology

Science.gov (United States)

Hewer, Micah J.; Scott, Daniel J.; Gough, William A.

2017-08-01

Weather and climate are important factors in relation to outdoor recreation and tourism. Camping and park visitation are weather sensitive activities very likely to be impacted by projected climate change. Temperature is the weather variable that has received the greatest attention within the tourism climatology literature and was the greatest predictor of park visitation within previous assessments. This study uses a stated climate preferences approach, relying on survey-based data, to explore differences for temperature preferences and thresholds among campers in Ontario parks. Statistically significant differences (at the 95% confidence level) in mean values for temperature preferences and thresholds were recorded based on various camper characteristics, such as the following: activity selection, age, gender, distance travelled, length of stay, life cycle stage, camping experience, and camping equipment. Swimmers preferred warmer day-time temperatures. Older campers preferred cooler temperatures and were more sensitive to heat stress, in the day and night time. Females preferred warmer temperatures and were less sensitive to heat stress during the night time. Campers who had travelled further distances to reach the park or planned to stay for longer periods were less sensitive to heat stress. Campers with children in their group preferred warmer temperatures and were less sensitive to heat stress, in the day and at night. Respondents with higher levels of camping experience preferred warmer temperatures at night. Tent campers were less sensitive to heat stress, in the day and at night. The results of this study have direct implications for previous and future climate change impact assessments on park visitation.

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

Climatology of salt transitions and implications for stone weathering

International Nuclear Information System (INIS)

Grossi, C.M.; Brimblecombe, P.; Menendez, B.; Benavente, D.; Harris, I.; Deque, M.

2011-01-01

This work introduces the notion of salt climatology. It shows how climate affects salt thermodynamic and the potential to relate long-term salt damage to climate types. It mainly focuses on specific sites in Western Europe, which include some cities in France and Peninsular Spain. Salt damage was parameterised using the number of dissolution-crystallisation events for unhydrated (sodium chloride) and hydrated (sodium sulphate) systems. These phase transitions have been calculated using daily temperature and relative humidity from observation meteorological data and Climate Change models' output (HadCM3 and ARPEGE). Comparing the number of transitions with meteorological seasonal data allowed us to develop techniques to estimate the frequency of salt transitions based on the local climatology. Results show that it is possible to associate the Koeppen-Geiger climate types with potential salt weathering. Temperate fully humid climates seem to offer the highest potential for salt damage and possible higher number of transitions in summer. Climates with dry summers tend to show a lesser frequency of transitions in summer. The analysis of temperature, precipitation and relative output from Climate Change models suggests changes in the Koeppen-Geiger climate types and changes in the patterns of salt damage. For instance, West Europe areas with a fully humid climate may change to a more Mediterranean like or dry climates, and consequently the seasonality of different salt transitions. The accuracy and reliability of the projections might be improved by simultaneously running multiple climate models (ensembles). - Research highlights: → We introduce the notion of salt climatology for heritage conservation. → Climate affects salt thermodynamics on building materials. → We associate Koeppen-Geiger climate types with potential salt weathering. → We offer future projections of salt damage in Western Europe due to climate change. → Humid climate areas may change to

Climatology of salt transitions and implications for stone weathering

Energy Technology Data Exchange (ETDEWEB)

Grossi, C.M., E-mail: c.grossi-sampedro@uea.ac.uk [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Brimblecombe, P. [School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Menendez, B. [Geosciences et Environnement Cergy, Universite de Cergy-Pontoise 95031 Cergy-Pontoise cedex (France); Benavente, D. [Lab. Petrologia Aplicada, Unidad Asociada UA-CSIC, Dpto. Ciencias de la Tierra y del Medio Ambiente, Universidad de Alicante, Alicante 03080 (Spain); Harris, I. [Climatic Research Unit, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Deque, M. [Meteo-France/CNRM, CNRS/GAME, 42 Avenue Coriolis, F-31057 Toulouse, Cedex 01 (France)

2011-06-01

This work introduces the notion of salt climatology. It shows how climate affects salt thermodynamic and the potential to relate long-term salt damage to climate types. It mainly focuses on specific sites in Western Europe, which include some cities in France and Peninsular Spain. Salt damage was parameterised using the number of dissolution-crystallisation events for unhydrated (sodium chloride) and hydrated (sodium sulphate) systems. These phase transitions have been calculated using daily temperature and relative humidity from observation meteorological data and Climate Change models' output (HadCM3 and ARPEGE). Comparing the number of transitions with meteorological seasonal data allowed us to develop techniques to estimate the frequency of salt transitions based on the local climatology. Results show that it is possible to associate the Koeppen-Geiger climate types with potential salt weathering. Temperate fully humid climates seem to offer the highest potential for salt damage and possible higher number of transitions in summer. Climates with dry summers tend to show a lesser frequency of transitions in summer. The analysis of temperature, precipitation and relative output from Climate Change models suggests changes in the Koeppen-Geiger climate types and changes in the patterns of salt damage. For instance, West Europe areas with a fully humid climate may change to a more Mediterranean like or dry climates, and consequently the seasonality of different salt transitions. The accuracy and reliability of the projections might be improved by simultaneously running multiple climate models (ensembles). - Research highlights: {yields} We introduce the notion of salt climatology for heritage conservation. {yields} Climate affects salt thermodynamics on building materials. {yields} We associate Koeppen-Geiger climate types with potential salt weathering. {yields} We offer future projections of salt damage in Western Europe due to climate change. {yields} Humid

Assessment of a global climatology of oceanic dimethylsulfide (DMS) concentrations based on SeaWiFS imagery (1998-2001)

NARCIS (Netherlands)

Belviso, S; Moulin, C; Bopp, L; Stefels, J

A method is developed to estimate sea-surface particulate dimethylsulfoniopropionate (DMSP(p)) and dimethylsulfide (DMS) concentrations from sea-surface concentrations of chlorophyll a (Chl a). When compared with previous studies, the 1degrees x 1degrees global climatology of oceanic DMS

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...

Analysis and modeling of the seasonal South China Sea temperature cycle using remote sensing

Science.gov (United States)

Twigt, Daniel J.; de Goede, Erik D.; Schrama, Ernst J. O.; Gerritsen, Herman

2007-10-01

The present paper describes the analysis and modeling of the South China Sea (SCS) temperature cycle on a seasonal scale. It investigates the possibility to model this cycle in a consistent way while not taking into account tidal forcing and associated tidal mixing and exchange. This is motivated by the possibility to significantly increase the model’s computational efficiency when neglecting tides. The goal is to develop a flexible and efficient tool for seasonal scenario analysis and to generate transport boundary forcing for local models. Given the significant spatial extent of the SCS basin and the focus on seasonal time scales, synoptic remote sensing is an ideal tool in this analysis. Remote sensing is used to assess the seasonal temperature cycle to identify the relevant driving forces and is a valuable source of input data for modeling. Model simulations are performed using a three-dimensional baroclinic-reduced depth model, driven by monthly mean sea surface anomaly boundary forcing, monthly mean lateral temperature, and salinity forcing obtained from the World Ocean Atlas 2001 climatology, six hourly meteorological forcing from the European Center for Medium range Weather Forecasting ERA-40 dataset, and remotely sensed sea surface temperature (SST) data. A sensitivity analysis of model forcing and coefficients is performed. The model results are quantitatively assessed against climatological temperature profiles using a goodness-of-fit norm. In the deep regions, the model results are in good agreement with this validation data. In the shallow regions, discrepancies are found. To improve the agreement there, we apply a SST nudging method at the free water surface. This considerably improves the model’s vertical temperature representation in the shallow regions. Based on the model validation against climatological in situ and SST data, we conclude that the seasonal temperature cycle for the deep SCS basin can be represented to a good degree. For shallow

International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 3 Monthly

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Global Land Surface Temperature Databank contains monthly timescale mean, maximum, and minimum temperature for approximately 40,000 stations globally. It was...

International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 2 Daily

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 2 Monthly

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 1 Monthly

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

International Surface Temperature Initiative (ISTI) Global Land Surface Temperature Databank - Stage 1 Daily

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The global land surface temperature databank contains monthly timescale mean, max, and min temperature for approximately 40,000 stations globally. It was developed...

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.

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

Determination of dynamic heights in the Bay of Bengal from XBT profiles and climatological salinities

Digital Repository Service at National Institute of Oceanography (India)

Ali, M.M.; Gopalakrishna, V.V.; Araligidad, N.; Reddy, G.V.; Salgaonkar, G.

errors compared to the DH signals are 3.8%, 2.7% and 2.6% for 200, 700 and 1000 dbar levels, respectively. The DHs relative to 700 dbar computed using the XBT temperature and climatological salinity profiles are compared with the SSH observations from...

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

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

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

Spatial relationship between climatologies and changes in global vegetation activity.

Science.gov (United States)

de Jong, Rogier; Schaepman, Michael E; Furrer, Reinhard; de Bruin, Sytze; Verburg, Peter H

2013-06-01

Vegetation forms a main component of the terrestrial biosphere and plays a crucial role in land-cover and climate-related studies. Activity of vegetation systems is commonly quantified using remotely sensed vegetation indices (VI). Extensive reports on temporal trends over the past decades in time series of such indices can be found in literature. However, little remains known about the processes underlying these changes at large spatial scales. In this study, we aimed at quantifying the spatial relationship between changes in potential climatic growth constraints (i.e. temperature, precipitation and incident solar radiation) and changes in vegetation activity (1982-2008). We demonstrate an additive spatial model with 0.5° resolution, consisting of a regression component representing climate-associated effects and a spatially correlated field representing the combined influence of other factors, including land-use change. Little over 50% of the spatial variance could be attributed to changes in climatologies; conspicuously, many greening trends and browning hotspots in Argentina and Australia. The nonassociated model component may contain large-scale human interventions, feedback mechanisms or natural effects, which were not captured by the climatologies. Browning hotspots in this component were especially found in subequatorial Africa. On the scale of land-cover types, strongest relationships between climatologies and vegetation activity were found in forests, including indications for browning under warming conditions (analogous to the divergence issue discussed in dendroclimatology). © 2013 Blackwell Publishing Ltd.

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 pages...

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

Directory of Open Access Journals (Sweden)

S. Salon

2003-03-01

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

Extreme Maximum Land Surface Temperatures.

Science.gov (United States)

Garratt, J. R.

1992-09-01

There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

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

International Nuclear Information System (INIS)

Piacsek, S.; Allard, R.; McClean, J.

2008-01-01

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 10 0 W-10 0 E and 60 0 N-70 0 N, 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 0 0 C 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

Improving Satellite Retrieved Infrared Sea Surface Temperatures in Aerosol-Contaminated Regions

Science.gov (United States)

Luo, B.; Minnett, P. J.; Szczodrak, G.; Kilpatrick, K. A.

2017-12-01

Infrared satellite observations of sea surface temperature (SST) have become essential for many applications in meteorology, climatology, and oceanography. Applications often require high accuracy SST data: for climate research and monitoring an absolute uncertainty of 0.1K and stability of better than 0.04K per decade are required. Tropospheric aerosol concentrations increase infrared signal attenuation and prevent the retrieval of accurate satellite SST. We compare satellite-derived skin SST with measurements from the Marine-Atmospheric Emitted Radiance Interferometer (M-AERI) deployed on ships during the Aerosols and Ocean Science Expeditions (AEROSE) and with quality-controlled drifter temperatures. After match-up with in-situ SST and filtering of cloud contaminated data, the results indicate that SST retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) aboard the Terra and Aqua satellites have negative (cool) biases compared to shipboard radiometric measurements. There is also a pronounced negative bias in the Saharan outflow area that can introduce SST errors >1 K at aerosol optical depths > 0.5. In this study, we present a new method to derive night-time Saharan Dust Index (SDI) algorithms based on simulated brightness temperatures at infrared wavelengths of 3.9, 10.8 and 12.0 μm, derived using RTTOV. We derived correction coefficients for Aqua MODIS measurements by regression of the SST errors against the SDI. The biases and standard deviations are reduced by 0.25K and 0.19K after the SDI correction. The goal of this study is to understand better the characteristics and physical mechanisms of aerosol effects on satellite retrieved infrared SST, as well as to derive empirical formulae for improved accuracies in aerosol-contaminated regions.

Merging daily sea surface temperature data from multiple satellites using a Bayesian maximum entropy method

Science.gov (United States)

Tang, Shaolei; Yang, Xiaofeng; Dong, Di; Li, Ziwei

2015-12-01

Sea surface temperature (SST) is an important variable for understanding interactions between the ocean and the atmosphere. SST fusion is crucial for acquiring SST products of high spatial resolution and coverage. This study introduces a Bayesian maximum entropy (BME) method for blending daily SSTs from multiple satellite sensors. A new spatiotemporal covariance model of an SST field is built to integrate not only single-day SSTs but also time-adjacent SSTs. In addition, AVHRR 30-year SST climatology data are introduced as soft data at the estimation points to improve the accuracy of blended results within the BME framework. The merged SSTs, with a spatial resolution of 4 km and a temporal resolution of 24 hours, are produced in the Western Pacific Ocean region to demonstrate and evaluate the proposed methodology. Comparisons with in situ drifting buoy observations show that the merged SSTs are accurate and the bias and root-mean-square errors for the comparison are 0.15°C and 0.72°C, respectively.

Constructing an AIRS Climatology for Data Visualization and Analysis to Serve the Climate Science and Application Communities

Science.gov (United States)

Ding, Feng; Keim, Elaine; Hearty, Thomas J.; Wei, Jennifer; Savtchenko, Andrey; Theobald, Michael; Vollmer, Bruce

2016-01-01

The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) is the home of processing, archiving, and distribution services for NASA sounders: the present Aqua AIRS mission and the succeeding SNPP CrIS mission. The AIRS mission is entering its 15th year of global observations of the atmospheric state, including temperature and humidity profiles, outgoing longwave radiation, cloud properties, and trace gases. The GES DISC, in collaboration with the AIRS Project, released product from the version 6 algorithm in early 2013. Giovanni, a Web-based application developed by the GES DISC, provides a simple and intuitive way to visualize, analyze, and access vast amounts of Earth science remote sensing data without having to download the data. Most important variables from version 6 AIRS product are available in Giovanni. We are developing a climatology product using 14-year AIRS retrievals. The study can be a good start for the long term climatology from NASA sounders: the AIRS and the succeeding CrIS. This presentation will show the impacts to the climatology product from different aggregation methods. The climatology can serve climate science and application communities in data visualization and analysis, which will be demonstrated using a variety of functions in version 4 Giovanni. The highlights of these functions include user-defined monthly and seasonal climatology, inter annual seasonal time series, anomaly analysis.

Extended Reconstructed Sea Surface Temperature (ERSST)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature analysis derived from the International Comprehensive...

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

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

International Nuclear Information System (INIS)

Rapp, Anita D; Lebsock, Matthew; L’Ecuyer, Tristan

2013-01-01

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)

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.

NOAA Global Surface Temperature (NOAAGlobalTemp)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Global Surface Temperature Dataset (NOAAGlobalTemp) is a merged land–ocean surface temperature analysis (formerly known as MLOST) (link is external). It is...

Variability of emissivity and surface temperature over a sparsely vegetated surface

International Nuclear Information System (INIS)

Humes, K.S.; Kustas, W.P.; Moran, M.S.; Nichols, W.D.; Weltz, M.A.

1994-01-01

Radiometric surface temperatures obtained from remote sensing measurements are a function of both the physical surface temperature and the effective emissivity of the surface within the band pass of the radiometric measurement. For sparsely vegetated areas, however, a sensor views significant fractions of both bare soil and various vegetation types. In this case the radiometric response of a sensor is a function of the emissivities and kinetic temperatures of various surface elements, the proportion of those surface elements within the field of view of the sensor, and the interaction of radiation emitted from the various surface components. In order to effectively utilize thermal remote sensing data to quantify energy balance components for a sparsely vegetated area, it is important to examine the typical magnitude and degree of variability of emissivity and surface temperature for such surfaces. Surface emissivity measurements and ground and low-altitude-aircraft-based surface temperature measurements (8-13 micrometer band pass) made in conjunction with the Monsoon '90 field experiment were used to evaluate the typical variability of those quantities during the summer rainy season in a semiarid watershed. The average value for thermal band emissivity of the exposed bare soil portions of the surface was found to be approximately 0.96; the average value measured for most of the varieties of desert shrubs present was approximately 0.99. Surface composite emissivity was estimated to be approximately 0.98 for both the grass-dominated and shrub-dominated portions of the watershed. The spatial variability of surface temperature was found to be highly dependent on the spatial scale of integration for the instantaneous field of view (IFOV) of the instrument, the spatial scale of the total area under evaluation, and the time of day

A quality control procedure for seawater temperature data

Digital Repository Service at National Institute of Oceanography (India)

Ghosh, A.K.; Pankajakshan, T.

temperature climatology derived from historical data. In each level, the quality flags are assigned for the inversion station, abnormal intracruise variability and climatologically abnormal station. The first two check are applied to the Indian National...

High-temperature morphology of stepped gold surfaces

International Nuclear Information System (INIS)

Bilalbegovic, G.; Tosatti, E.; Ercolessi, F.

1992-04-01

Molecular dynamics simulations with a classical many-body potential are used to study the high-temperature stability of stepped non-melting metal surfaces. We have studied in particular the Au(111) vicinal surfaces in the (M+1, M-1, M) family and the Au(100) vicinals in the (M, 1, 1) family. Some vicinal orientations close to the non-melting Au(111) surface become unstable close to the bulk melting temperature and facet into a mixture of crystalline (111) regions and localized surface-melted regions. On the contrary, we do not find high-temperature faceting for vicinals close to Au(100), also a non-melting surface. These (100) vicinal surfaces gradually disorder with disappearance of individual steps well below the bulk melting temperature. We have also studied the high-temperature stability of ledges formed by pairs of monoatomic steps of opposite sign on the Au(111) surface. It is found that these ledges attract each other, so that several of them merge into one larger ledge, whose edge steps then act as a nucleation site for surface melting. (author). 43 refs, 8 figs

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.

Hanford Site Climatological Data Summary 2001 with Historical Data

International Nuclear Information System (INIS)

Hoitink, Dana J.; Ramsdell, James V.; Shaw, Wendy J.

2001-01-01

This document presents the climatological data measured at the U. S. Department of Energy's Hanford Site for calendar year 2001. Pacific Northwest National Laboratory operates the Hanford Meteorology Station and the Hanford Meteorological Monitoring Network from which these data were collected. This report contains updated historical information 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 others) (1999, 2000, 2001) and Hoitink and Burk (1994, 1995, 1996, 1997, 1998); however, data from Appendix B--Wind Climatology (Hoitink (and others) 1994) are excluded. Calendar year 2001 was slightly warmer than normal at the Hanford Meteorology Station with an average temperature of 54.3 F, 0.7 F above normal (53.6 F). The hottest temperature was 106 F on July 4, while the coldest was 16 F on December 25. For the 12-month period, 8 months were warmer than normal, and 4 months were cooler than normal. Precipitation for 2001 totaled 6.66 inches, 95% of normal (6.98 inches); calendar year snowfall totaled 15.1 inches (compared to the normal of 15.4 inches). Calendar year 2001 had an average wind speed of 7.6 mph, which was normal (7.6 mph). There were 31 days with peak gusts (ge)40 mph, compared to a yearly average of 27 days. The peak gust during the year was 69 mph on December 16. November 2001 established new records for both days and hours with dense fog (visibility (le)1/4 mile). There were 14 days and 99.4 hours of dense fog reported, compared to an average of 5.5 days with 22.0 hours. The previous record was 13 days in 1965 and 71.4 hours in 1952. The heating-degree days for 2000-2001 were 5,516 (7% above the 5,160 normal). Cooling-degree days for 2001 were 1,092 (8% above the 1,014 normal)

On the daily cycle of the climatological variables in the Municipality of Quibdo

International Nuclear Information System (INIS)

Pabon, Jose Daniel; Reiner Palomino Lemus; William Murillo Lopez

2005-01-01

We analyzed the daily cycle of the climatological variables (solar radiation, air temperature, atmospheric pressure, precipitation and wind) in Quibdo, (5.45 degrades N and 76.39 degrades W, 53m), department of Choco. The analysis is based on hourly data recorded during the period 2000-2004 at the meteorological and radiometric station of the technological university of Choco, Diego Luis Cordoba (UTCH). It is shown that the daily cycle of the climatological variables in the city of Quibdo is typical of the tropical areas and the particularities of the daily pattern of precipitation were found: most of the rains occur during the evening. The seasonal variation of the daily cycle was also established. Finally, an approximation was made to the analyses of the effect of extreme phases of inter annual climate variability associated to El Nino and la Nina

Ranking Of The Performance Of Some Climatological Parameters In The Easement Of Solar Radiation In The Mina Environment Central Nigeria

International Nuclear Information System (INIS)

Abubakar, S.Y.

2004-01-01

Four models each based on a single climatological factors were proposed to evaluate the strength of the performance of each parameter in estimating solar radiation in Minna. The climatological parameters are percentage of sunshine hours, temperature ratio, humidity and cloud cover. Based on the MAB and RMSE method the sunshine hours duration was found to be the most efficient parameter for predicting the monthly and annual performance of models compared with the model based on the temperature ratio closely follow the model based on sunshine data while model based on the cloud cover was found to have the worst performance. Generally the model based on the sunshine hours performed better than the rest during the rainy season while the model based on the temperature ratio outperformed the rest of the models during the harmattan season. However both models based on the sunshine hours and temperature ratio were equally found to have good performance during the dry season

Climatology of salt transitions and implications for stone weathering.

Science.gov (United States)

Grossi, C M; Brimblecombe, P; Menéndez, B; Benavente, D; Harris, I; Déqué, M

2011-06-01

This work introduces the notion of salt climatology. It shows how climate affects salt thermodynamic and the potential to relate long-term salt damage to climate types. It mainly focuses on specific sites in Western Europe, which include some cities in France and Peninsular Spain. Salt damage was parameterised using the number of dissolution-crystallisation events for unhydrated (sodium chloride) and hydrated (sodium sulphate) systems. These phase transitions have been calculated using daily temperature and relative humidity from observation meteorological data and Climate Change models' output (HadCM3 and ARPEGE). Comparing the number of transitions with meteorological seasonal data allowed us to develop techniques to estimate the frequency of salt transitions based on the local climatology. Results show that it is possible to associate the Köppen-Geiger climate types with potential salt weathering. Temperate fully humid climates seem to offer the highest potential for salt damage and possible higher number of transitions in summer. Climates with dry summers tend to show a lesser frequency of transitions in summer. The analysis of temperature, precipitation and relative output from Climate Change models suggests changes in the Köppen-Geiger climate types and changes in the patterns of salt damage. For instance, West Europe areas with a fully humid climate may change to a more Mediterranean like or dry climates, and consequently the seasonality of different salt transitions. The accuracy and reliability of the projections might be improved by simultaneously running multiple climate models (ensembles). Copyright © 2011 Elsevier B.V. All rights reserved.

SEASONAL CHANGES IN TITAN'S SURFACE TEMPERATURES

International Nuclear Information System (INIS)

Jennings, D. E.; Cottini, V.; Nixon, C. A.; Flasar, F. M.; Kunde, V. G.; Samuelson, R. E.; Romani, P. N.; Hesman, B. E.; Carlson, R. C.; Gorius, N. J. P.; Coustenis, A.; Tokano, T.

2011-01-01

Seasonal changes in Titan's surface brightness temperatures have been observed by Cassini in the thermal infrared. The Composite Infrared Spectrometer measured surface radiances at 19 μm in two time periods: one in late northern winter (LNW; L s = 335 deg.) and another centered on northern spring equinox (NSE; L s = 0 deg.). In both periods we constructed pole-to-pole maps of zonally averaged brightness temperatures corrected for effects of the atmosphere. Between LNW and NSE a shift occurred in the temperature distribution, characterized by a warming of ∼0.5 K in the north and a cooling by about the same amount in the south. At equinox the polar surface temperatures were both near 91 K and the equator was at 93.4 K. We measured a seasonal lag of ΔL S ∼ 9 0 in the meridional surface temperature distribution, consistent with the post-equinox results of Voyager 1 as well as with predictions from general circulation modeling. A slightly elevated temperature is observed at 65 0 S in the relatively cloud-free zone between the mid-latitude and southern cloud regions.

Impact of Vegetation Cover Fraction Parameterization schemes on Land Surface Temperature Simulation in the Tibetan Plateau

Science.gov (United States)

Lv, M.; Li, C.; Lu, H.; Yang, K.; Chen, Y.

2017-12-01

The parameterization of vegetation cover fraction (VCF) is an important component of land surface models. This paper investigates the impacts of three VCF parameterization schemes on land surface temperature (LST) simulation by the Common Land Model (CoLM) in the Tibetan Plateau (TP). The first scheme is a simple land cover (LC) based method; the second one is based on remote sensing observation (hereafter named as RNVCF) , in which multi-year climatology VCFs is derived from Moderate-resolution Imaging Spectroradiometer (MODIS) NDVI (Normalized Difference Vegetation Index); the third VCF parameterization scheme derives VCF from the LAI simulated by LSM and clump index at every model time step (hereafter named as SMVCF). Simulated land surface temperature(LST) and soil temperature by CoLM with three VCF parameterization schemes were evaluated by using satellite LST observation and in situ soil temperature observation, respectively, during the period of 2010 to 2013. The comparison against MODIS Aqua LST indicates that (1) CTL produces large biases for both four seasons in early afternoon (about 13:30, local solar time), while the mean bias in spring reach to 12.14K; (2) RNVCF and SMVCF reduce the mean bias significantly, especially in spring as such reduce is about 6.5K. Surface soil temperature observed at 5 cm depth from three soil moisture and temperature monitoring networks is also employed to assess the skill of three VCF schemes. The three networks, crossing TP from West to East, have different climate and vegetation conditions. In the Ngari network, located in the Western TP with an arid climate, there are not obvious differences among three schemes. In Naqu network, located in central TP with a semi-arid climate condition, CTL shows a severe overestimates (12.1 K), but such overestimations can be reduced by 79% by RNVCF and 87% by SMVCF. In the third humid network (Maqu in eastern TP), CoLM performs similar to Naqu. However, at both Naqu and Maqu networks

The climatology of the Red Sea - part 2: the waves

KAUST Repository

Langodan, Sabique

2017-05-09

The wave climatology of the Red Sea is described based on a 30-year hindcast generated using WAVEWATCH III configured on a 5-km resolution grid and forced by Red Sea reanalysis surface winds from the advanced Weather Research and Forecasting model. The wave simulations have been validated using buoy and altimeter data. The four main wind systems in the Red Sea characterize the corresponding wave climatology. The dominant ones are the two opposite wave systems with different genesis, propagating along the axis of the basin. The highest waves are generated at the centre of the Red Sea as a consequence of the strong seasonal winds blowing from the Tokar Gap on the African side. There is a general long-term trend toward lowering the values of the significant wave height over the whole basin, with a decreasing rate depending on the genesis of the individual systems.

A global ocean climatological atlas of the Turner angle: implications for double-diffusion and water-mass structure

Science.gov (United States)

You, Yuzhu

2002-11-01

The 1994 Levitus climatological atlas is used to calculate the Turner angle (named after J. Stewart Turner) to examine which oceanic water masses are favorable for double-diffusion in the form of diffusive convection or salt-fingering and which are doubly stable. This atlas complements the Levitus climatology. It reveals the major double-diffusive signals associated with large-scale water-mass structure. In total, about 44% of the oceans display double-diffusion, of which 30% is salt-fingering and 14% is diffusive double-diffusion. Results show that various central and deep waters are favorable for salt-fingering. The former is due to positive evaporation minus precipitation, and the latter is due to thermohaline circulation, i.e. the southward spreading of relatively warm, salty North Atlantic Deep Water (NADW) overlying cold, fresh Antarctic Bottom Water. In the northern Indian Ocean and eastern North Atlantic, favorable conditions for salt-fingering are found throughout the water column. The Red Sea (including the Persian Gulf) and Mediterranean Sea are the sources of warm, salty water for the ocean. As consequence, temperature and salinity in these outflow regions both decrease from the sea surface to the bottom. On the other hand, ocean currents are in general sluggish in these regions. In the polar and subpolar regions of Arctic and Antarctic, Okhotsk Sea, Gulf of Alaska, the subpolar gyre of the North Pacific, the Labrador Sea, and the Norwegian Sea, the upper layer water is favorable for diffusive convection because of high latitude surface cooling and ice melting. Weak and shallow diffusive convection is also found throughout tropical regions and the Bay of Bengal. The former is due to excessive precipitation over evaporation and rain cooling, and the latter is due to both precipitation and river runoff. Diffusive convection in the ocean's interior is unique to the South Atlantic between Antarctic Intermediate Water and upper NADW (uNADW). It is the

Multiproxy summer and winter surface air temperature field reconstructions for southern South America covering the past centuries

Energy Technology Data Exchange (ETDEWEB)

Neukom, R.; Grosjean, M.; Wanner, H. [University of Bern, Oeschger Centre for Climate Change Research (OCCR), Bern (Switzerland); University of Bern, Institute of Geography, Climatology and Meteorology, Bern (Switzerland); Luterbacher, J. [Justus Liebig University of Giessen, Department of Geography, Climatology, Climate Dynamics and Climate Change, Giessen (Germany); Villalba, R.; Morales, M.; Srur, A. [CONICET, Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales (IANIGLA), Mendoza (Argentina); Kuettel, M. [University of Bern, Oeschger Centre for Climate Change Research (OCCR), Bern (Switzerland); University of Bern, Institute of Geography, Climatology and Meteorology, Bern (Switzerland); University of Washington, Department of Earth and Space Sciences, Seattle (United States); Frank, D. [Swiss Federal Research Institute WSL, Birmensdorf (Switzerland); Jones, P.D. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Aravena, J.-C. [Centro de Estudios Cuaternarios de Fuego Patagonia y Antartica (CEQUA), Punta Arenas (Chile); Black, D.E. [Stony Brook University, School of Marine and Atmospheric Sciences, Stony Brook (United States); Christie, D.A.; Urrutia, R. [Universidad Austral de Chile Valdivia, Laboratorio de Dendrocronologia, Facultad de Ciencias Forestales y Recursos Naturales, Valdivia (Chile); D' Arrigo, R. [Earth Institute at Columbia University, Tree-Ring Laboratory, Lamont-Doherty Earth Observatory, Palisades, NY (United States); Lara, A. [Universidad Austral de Chile Valdivia, Laboratorio de Dendrocronologia, Facultad de Ciencias Forestales y Recursos Naturales, Valdivia (Chile); Nucleo Cientifico Milenio FORECOS, Fundacion FORECOS, Valdivia (Chile); Soliz-Gamboa, C. [Utrecht Univ., Inst. of Environmental Biology, Utrecht (Netherlands); Gunten, L. von [Univ. of Bern (Switzerland); Univ. of Massachusetts, Climate System Research Center, Amherst (United States)

2011-07-15

We statistically reconstruct austral summer (winter) surface air temperature fields back to ad 900 (1706) using 22 (20) annually resolved predictors from natural and human archives from southern South America (SSA). This represents the first regional-scale climate field reconstruction for parts of the Southern Hemisphere at this high temporal resolution. We apply three different reconstruction techniques: multivariate principal component regression, composite plus scaling, and regularized expectation maximization. There is generally good agreement between the results of the three methods on interannual and decadal timescales. The field reconstructions allow us to describe differences and similarities in the temperature evolution of different sub-regions of SSA. The reconstructed SSA mean summer temperatures between 900 and 1350 are mostly above the 1901-1995 climatology. After 1350, we reconstruct a sharp transition to colder conditions, which last until approximately 1700. The summers in the eighteenth century are relatively warm with a subsequent cold relapse peaking around 1850. In the twentieth century, summer temperatures reach conditions similar to earlier warm periods. The winter temperatures in the eighteenth and nineteenth centuries were mostly below the twentieth century average. The uncertainties of our reconstructions are generally largest in the eastern lowlands of SSA, where the coverage with proxy data is poorest. Verifications with independent summer temperature proxies and instrumental measurements suggest that the interannual and multi-decadal variations of SSA temperatures are well captured by our reconstructions. This new dataset can be used for data/model comparison and data assimilation as well as for detection and attribution studies at sub-continental scales. (orig.)

Simulation of the summer circulation over South America by two regional climate models. Part I: Mean climatology

Science.gov (United States)

Fernandez, J. P. R.; Franchito, S. H.; Rao, V. B.

2006-09-01

This study investigates the capabilities of two regional models (the ICTP RegCM3 and the climate version of the CPTEC Eta model - EtaClim) in simulating the mean climatological features of the summer quasi-stationary circulations over South America. Comparing the results with the NCEP/DOE reanalysis II data it is seen that the RegCM3 simulates a weaker and southward shifted Bolivian high (BH). But, the Nordeste low (NL) is located close to its climatological position. In the EtaClim the position of the BH is reproduced well, but the NL is shifted towards the interior of the continent. To the east of Andes, the RegCM3 simulates a weaker low level jet and a weaker basic flow from the tropical Atlantic to Amazonia while they are stronger in the EtaClim. In general, the RegCM3 and EtaClim show, respectively a negative and positive bias in the surface temperature in almost all regions of South America. For both models, the correlation coefficients between the simulated precipitation and the GPCP data are high over most of South America. Although the RegCM3 and EtaClim overestimate the precipitation in the Andes region they show a negative bias in general over the entire South America. The simulations of upper and lower level circulations and precipitation fields in EtaClim were better than that of the RegCM3. In central Amazonia both models were unable to simulate the precipitation correctly. The results showed that although the RegCM3 and EtaClim are capable of simulating the main climatological features of the summer climate over South America, there are areas which need improvement. This indicates that the models must be more adequately tuned in order to give reliable predictions in the different regions of South America.

Temperature dependence of surface nanobubbles

NARCIS (Netherlands)

Berkelaar, R.P.; Seddon, James Richard Thorley; Zandvliet, Henricus J.W.; Lohse, Detlef

2012-01-01

The temperature dependence of nanobubbles was investigated experimentally using atomic force microscopy. By scanning the same area of the surface at temperatures from 51 °C to 25 °C it was possible to track geometrical changes of individual nanobubbles as the temperature was decreased.

Outdoor surface temperature measurement: ground truth or lie?

Science.gov (United States)

Skauli, Torbjorn

2004-08-01

Contact surface temperature measurement in the field is essential in trials of thermal imaging systems and camouflage, as well as for scene modeling studies. The accuracy of such measurements is challenged by environmental factors such as sun and wind, which induce temperature gradients around a surface sensor and lead to incorrect temperature readings. In this work, a simple method is used to test temperature sensors under conditions representative of a surface whose temperature is determined by heat exchange with the environment. The tested sensors are different types of thermocouples and platinum thermistors typically used in field trials, as well as digital temperature sensors. The results illustrate that the actual measurement errors can be much larger than the specified accuracy of the sensors. The measurement error typically scales with the difference between surface temperature and ambient air temperature. Unless proper care is taken, systematic errors can easily reach 10% of this temperature difference, which is often unacceptable. Reasonably accurate readings are obtained using a miniature platinum thermistor. Thermocouples can perform well on bare metal surfaces if the connection to the surface is highly conductive. It is pointed out that digital temperature sensors have many advantages for field trials use.

Climatological effects on heliohydroelectric (HHE) power generation. [Based on evaporation

Energy Technology Data Exchange (ETDEWEB)

Kettani, M A

1973-12-01

Large scale conversion of solar energy into electricity can be efficiently made by transforming first the solar energy into hydraulic energy by evaporation. This concept has been presented at the International Conference of 1971. Since then work has been done to correlate the power generated by an HHE plant to the climatological variables of a region. The effects of such variables as air temperature, relative humidity, station pressure, and wind speed on the generated power are discussed. The Dawhat Salwah area is being emphasized; however, the results could be generalized to other arid zones.

A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations

Science.gov (United States)

Spang, Reinhold; Hoffmann, Lars; Müller, Rolf; Grooß, Jens-Uwe; Tritscher, Ines; Höpfner, Michael; Pitts, Michael; Orr, Andrew; Riese, Martin

2018-04-01

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument aboard the European Space Agency (ESA) Envisat satellite operated from July 2002 to April 2012. The infrared limb emission measurements provide a unique dataset of day and night observations of polar stratospheric clouds (PSCs) up to both poles. A recent classification method for PSC types in infrared (IR) limb spectra using spectral measurements in different atmospheric window regions has been applied to the complete mission period of MIPAS. The method uses a simple probabilistic classifier based on Bayes' theorem with a strong independence assumption on a combination of a well-established two-colour ratio method and multiple 2-D probability density functions of brightness temperature differences. The Bayesian classifier distinguishes between solid particles of ice, nitric acid trihydrate (NAT), and liquid droplets of supercooled ternary solution (STS), as well as mixed types. A climatology of MIPAS PSC occurrence and specific PSC classes has been compiled. Comparisons with results from the classification scheme of the spaceborne lidar Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite show excellent correspondence in the spatial and temporal evolution for the area of PSC coverage (APSC) even for each PSC class. Probability density functions of the PSC temperature, retrieved for each class with respect to equilibrium temperature of ice and based on coincident temperatures from meteorological reanalyses, are in accordance with the microphysical knowledge of the formation processes with respect to temperature for all three PSC types.This paper represents unprecedented pole-covering day- and nighttime climatology of the PSC distributions and their composition of different particle types. The dataset allows analyses on the temporal and spatial development of the PSC formation process over

A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations

Directory of Open Access Journals (Sweden)

R. Spang

2018-04-01

Full Text Available The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS instrument aboard the European Space Agency (ESA Envisat satellite operated from July 2002 to April 2012. The infrared limb emission measurements provide a unique dataset of day and night observations of polar stratospheric clouds (PSCs up to both poles. A recent classification method for PSC types in infrared (IR limb spectra using spectral measurements in different atmospheric window regions has been applied to the complete mission period of MIPAS. The method uses a simple probabilistic classifier based on Bayes' theorem with a strong independence assumption on a combination of a well-established two-colour ratio method and multiple 2-D probability density functions of brightness temperature differences. The Bayesian classifier distinguishes between solid particles of ice, nitric acid trihydrate (NAT, and liquid droplets of supercooled ternary solution (STS, as well as mixed types. A climatology of MIPAS PSC occurrence and specific PSC classes has been compiled. Comparisons with results from the classification scheme of the spaceborne lidar Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP on the Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations (CALIPSO satellite show excellent correspondence in the spatial and temporal evolution for the area of PSC coverage (APSC even for each PSC class. Probability density functions of the PSC temperature, retrieved for each class with respect to equilibrium temperature of ice and based on coincident temperatures from meteorological reanalyses, are in accordance with the microphysical knowledge of the formation processes with respect to temperature for all three PSC types.This paper represents unprecedented pole-covering day- and nighttime climatology of the PSC distributions and their composition of different particle types. The dataset allows analyses on the temporal and spatial development of the PSC formation

Disentangling sea-surface temperature and anthropogenic aerosol influences on recent trends in South Asian monsoon rainfall

Science.gov (United States)

Patil, Nitin; Venkataraman, Chandra; Muduchuru, Kaushik; Ghosh, Subimal; Mondal, Arpita

2018-05-01

Recent studies point to combined effects of changes in regional land-use, anthropogenic aerosol forcing and sea surface temperature (SST) gradient on declining trends in the South Asian monsoon (SAM). This study attempted disentangling the effects produced by changes in SST gradient from those by aerosol levels in an atmospheric general circulation model. Two pairs of transient ensemble simulations were made, for a 40-year period from 1971 to 2010, with evolving versus climatological SSTs and with anthropogenic aerosol emissions fixed at 1971 versus 2010, in each case with evolution of the other forcing element, as well as GHGs. Evolving SST was linked to a widespread feedback on increased surface temperature, reduced land-sea thermal contrast and a weakened Hadley circulation, with weakening of cross-equatorial transport of moisture transport towards South Asia. Increases in anthropogenic aerosol levels (1971 versus 2010), led to an intensification of drying in the peninsular Indian region, through several regional pathways. Aerosol forcing induced north-south asymmetries in temperature and sea-level pressure response, and a cyclonic circulation in the Bay of Bengal, leading to an easterly flow, which opposes the monsoon flow, suppressing moisture transport over peninsular India. Further, aerosol induced decreases in convection, vertically integrated moisture flux convergence, evaporation flux and cloud fraction, in the peninsular region, were spatially congruent with reduced convective and stratiform rainfall. Overall, evolution of SST acted through a weakening of cross-equatorial moisture flow, while increases in aerosol levels acted through suppression of Arabian Sea moisture transport, as well as, of convection and vertical moisture transport, to influence the suppression of SAM rainfall.

Low temperature self-cleaning properties of superhydrophobic surfaces

Science.gov (United States)

Wang, Fajun; Shen, Taohua; Li, Changquan; Li, Wen; Yan, Guilong

2014-10-01

Outdoor surfaces are usually dirty surfaces. Ice accretion on outdoor surfaces could lead to serious accidents. In the present work, the superhydrophobic surface based on 1H, 1H, 2H, 2H-Perfluorodecanethiol (PFDT) modified Ag/PDMS composite was prepared to investigate the anti-icing property and self-cleaning property at temperatures below freezing point. The superhydrophobic surface was deliberately polluted with activated carbon before testing. It was observed that water droplet picked up dusts on the cold superhydrophobic surface and took it away without freezing at a measuring temperature of -10 °C. While on a smooth PFDT surface and a rough surface base on Ag/PDMS composite without PFDT modification, water droplets accumulated and then froze quickly at the same temperature. However, at even lower temperature of -12 °C, the superhydrophobic surface could not prevent the surface water from icing. In addition, it was observed that the frost layer condensed from the moisture pay an important role in determining the low temperature self-cleaning properties of a superhydrophobic surface.

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.

16 year climatology of cirrus clouds over a tropical station in southern India using ground and space-based lidar observations

Science.gov (United States)

Pandit, A. K.; Gadhavi, H. S.; Venkat Ratnam, M.; Raghunath, K.; Rao, S. V. B.; Jayaraman, A.

2015-06-01

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.

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

Sudden temperature changes in the Sydney Basin: climatology and case studies during the Olympic months of September and October

Science.gov (United States)

Buckley, Bruce W.; Leslie, Lance M.

2000-03-01

The accurate prediction of sudden large changes in the maximum temperature from one day to the next remains one of the major challenges for operational forecasters. It is probably the meteorological parameter most commonly verified and used as a measure of the skill of a meteorological service and one that is immediately evident to the general public. Marked temperature changes over a short period of time have widespread social, economic, health and safety effects on the community. The first part of this paper describes a 40-year climatology for Sydney, Australia, of sudden temperature rises and falls, defined as maximum temperature changes of 5°C or more from one day to the next, for the months of September and October. The nature of the forecasting challenge during the period of the Olympic and Paralympic Games to be held in Sydney in the year 2000 will be described as a special application. The international importance of the accurate prediction of all types of significant weather phenomena during this period has been recognized by the World Meteorological Organisation's Commission for Atmospheric Science. The first World Weather Research Program forecast demonstration project is to be established in the Sydney Office of the Bureau of Meteorology over this period in order to test the ability of existing systems to predict such phenomena. The second part of this study investigates two case studies from the Olympic months in which there were both abrupt temperature rises and falls over a 4-day interval. Currently available high resolution numerical weather prediction systems are found to have significant skill several days ahead in predicting a large amount of the detail of these events, provided they are run at an appropriate resolution. The limitations of these systems are also discussed, with areas requiring further development being identified if the desired levels of accuracy of predictions are to be reliably delivered. Differences between the predictability

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...

Development and evaluation of climatologically-downscaled AFWA AGRMET precipitation products over the continental U.S.

Science.gov (United States)

Garcia, M.; Peters-Lidard, C. D.; Eylander, J. B.; Daly, C.; Gibson, W.; Tian, Y.; Zeng, J.; Kato, H.

2008-05-01

Collaborations between the Air Force Weather Agency (AFWA), the Hydrological Sciences Branch at NASA-GSFC, and the PRISM Group at Oregon State University have led to improvements in the processing of meteorological forcing inputs for the NASA-GSFC Land Information System (LIS; Kumar et al. 2006), a sophisticated framework for LSM operation and model coupling experiments. Efforts at AFWA toward the production of surface hydrometeorological products are currently in transition from the legacy Agricultural Meteorology modeling system (AGRMET) to use of the LIS framework and procedures. Recent enhancements to meteorological input processing for application to land surface models in LIS include the assimilation of climate-based information for the spatial interpolation and downscaling of precipitation fields. Climatological information included in the LIS- based downscaling procedure for North America is provided by a monthly high-resolution PRISM (Daly et al. 1994, 2002; Daly 2006) dataset based on a 30-year analysis period. The combination of these sources and methods attempts to address the strengths and weaknesses of available legacy products, objective interpolation methods, and the PRISM knowledge-based methodology. All of these efforts are oriented on an operational need for timely estimation of spatial precipitation fields at adequate spatial resolution for customer dissemination and near-real-time simulations in regions of interest. This work focuses on value added to the AGRMET precipitation product by the inclusion of high-quality climatological information on a monthly time scale. The AGRMET method uses microwave-based satellite precipitation estimates from various polar-orbiting platforms (NOAA POES and DMSP), infrared-based estimates from geostationary platforms (GOES, METEOSAT, etc.), related cloud analysis products, and surface gauge observations in a complex and hierarchical blending process. Results from processing of the legacy AGRMET precipitation

A Surface Temperature Initiated Closure (STIC) for surface energy balance fluxes

DEFF Research Database (Denmark)

Mallick, Kaniska; Jarvis, Andrew J.; Boegh, Eva

2014-01-01

The use of Penman–Monteith (PM) equation in thermal remote sensing based surface energy balance modeling is not prevalent due to the unavailability of any direct method to integrate thermal data into the PM equation and due to the lack of physical models expressing the surface (or stomatal......) and boundary layer conductances (gS and gB) as a function of surface temperature. Here we demonstrate a new method that physically integrates the radiometric surface temperature (TS) into the PM equation for estimating the terrestrial surface energy balance fluxes (sensible heat, H and latent heat, λ......E). The method combines satellite TS data with standard energy balance closure models in order to derive a hybrid closure that does not require the specification of surface to atmosphere conductance terms. We call this the Surface Temperature Initiated Closure (STIC), which is formed by the simultaneous solution...

Teaching Climatology and Meterology

OpenAIRE

Waddington, Shelagh B.

1997-01-01

Climatology and meteorology are often regarded as very difficult to teach by teachers and very hard to learn by students. This paper presents simple practical exercises which will enable teachers to make the topic of greater interest and easier for students to understand some of the basic ideas.

Estimation of land surface temperature of Kaduna metropolis ...

African Journals Online (AJOL)

Estimation of land surface temperature of Kaduna metropolis, Nigeria using landsat images. Isa Zaharaddeen, Ibrahim I. Baba, Ayuba Zachariah. Abstract. Understanding the spatial variation of Land Surface Temperature (LST), will be helpful in urban micro climate studies. This study estimates the land surface temperature ...

High-Temperature Surface-Acoustic-Wave Transducer

Science.gov (United States)

Zhao, Xiaoliang; Tittmann, Bernhard R.

2010-01-01

Aircraft-engine rotating equipment usually operates at high temperature and stress. Non-invasive inspection of microcracks in those components poses a challenge for the non-destructive evaluation community. A low-profile ultrasonic guided wave sensor can detect cracks in situ. The key feature of the sensor is that it should withstand high temperatures and excite strong surface wave energy to inspect surface/subsurface cracks. As far as the innovators know at the time of this reporting, there is no existing sensor that is mounted to the rotor disks for crack inspection; the most often used technology includes fluorescent penetrant inspection or eddy-current probes for disassembled part inspection. An efficient, high-temperature, low-profile surface acoustic wave transducer design has been identified and tested for nondestructive evaluation of structures or materials. The development is a Sol-Gel bismuth titanate-based surface-acoustic-wave (SAW) sensor that can generate efficient surface acoustic waves for crack inspection. The produced sensor is very thin (submillimeter), and can generate surface waves up to 540 C. Finite element analysis of the SAW transducer design was performed to predict the sensor behavior, and experimental studies confirmed the results. One major uniqueness of the Sol-Gel bismuth titanate SAW sensor is that it is easy to implement to structures of various shapes. With a spray coating process, the sensor can be applied to surfaces of large curvatures. Second, the sensor is very thin (as a coating) and has very minimal effect on airflow or rotating equipment imbalance. Third, it can withstand temperatures up to 530 C, which is very useful for engine applications where high temperature is an issue.

NORSEWInD satellite wind climatology

DEFF Research Database (Denmark)

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

The EU-NORSEWInD project www.norsewind.eu has taken place from August 2008 to July 2012 (4 years). NORSEWInD is short for Northern Seas Wind Index database. In the project ocean surface wind observations from space have been retrieved, processed and analysed. The overall aim of the work...... is to 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 the Irish Sea to more than 1200 in most of the Baltic Sea. Wind resource statistics include maps at 2 km spatial resolution of mean wind speed, Weibull A and k, and energy density at 10 m above sea level. Uncertainty estimates on the number of available samples for each of the four parameters are presented...

Global Synoptic Climatology Network (GSCN)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Dataset DSI-9290 is the result of a joint effort to create a Global Synoptic Climatology Network among the Meteorological Service of Canada (Downsview, Ontario and...

GODAE, SFCOBS - Surface Temperature Observations, 1998-present

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — GODAE, SFCOBS - Surface Temperature Observations: Ship, fixed/drifting buoy, and CMAN in-situ surface temperature. Global Telecommunication System (GTS) Data. The...

Growing season boundary layer climate and surface exchanges in a subarctic lichen woodland

Science.gov (United States)

Fitzjarrald, David R.; Moore, Kathleen E.

1994-01-01

Between June and August 1990, observations were made at two surface micrometeorological towers near Schefferville Quebec (54 deg 52 min N, 66 deg 40.5 min W), one in a fen and one in the subarctic lichen woodland, and at four surface climatological stations. Data from these surface stations were supplemented by regular radiosonde launches. Supporting measurements of radiative components and soil temperatures allowed heat and moisture balances to be obtained at two sites. The overall surface meteorological experiment design and results of micrometeorological observations made on a 30-m tower in the lichen woodland are presented here. Seasonal variation in the heat and water vapor transport characteristics illustrate the marked effect of the late summer climatological shift in air mass type. During the first half of the summer, average valley sidewalls only 100 m high are sufficient to channel winds along the valley in the entire convective boundary layer. Channeling effects at the surface, known for some time at the long-term climate station in Schefferville, are observed both at ridge top and in the valley, possibly the response of the flow to the NW-SE orientation of valleys in the region. Diurnal surface temperature amplitude at ridge top (approximately equal to 10 C) was found to be half that observed in the valley. Relatively large differences in precipitation among these stations and the climatological station at Schefferville airport were observed and attributed to the local topography. Eddy correlation observations of the heat, moisture and momentum transports were obtained from a 30-m tower above a sparse (approximately equal to 616 stems/ha) black spruce lichen woodland. Properties of the turbulent surface boundary layer agree well with previous wind tunnel studies over idealized rough surfaces. Daytime Bowen ratios of 2.5-3 are larger than those reported in previous studies. Surface layer flux data quality was assessed by looking at the surface layer heat

The Global Climatology Network Precipitation data

International Nuclear Information System (INIS)

Peterson, T.C.; Easterling, D.R.; Eischeid, J.K.

1993-01-01

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)

The effects of sea surface temperature anomalies on oceanic coral reef systems in the southwestern tropical Atlantic

Science.gov (United States)

Ferreira, B. P.; Costa, M. B. S. F.; Coxey, M. S.; Gaspar, A. L. B.; Veleda, D.; Araujo, M.

2013-06-01

In 2010, high sea surface temperatures that were recorded in several parts of the world and caused coral bleaching and coral mortality were also recorded in the southwest Atlantic Ocean, between latitudes 0°S and 8°S. This paper reports on coral bleaching and diseases in Rocas Atoll and Fernando de Noronha archipelago and examines their relationship with sea surface temperature (SST) anomalies recorded by PIRATA buoys located at 8°S30°W, 0°S35°W, and 0°S23°W. Adjusted satellite data were used to derive SST climatological means at buoy sites and to derive anomalies at reef sites. The whole region was affected by the elevated temperature anomaly that persisted through 2010, reaching 1.67 °C above average at reef sites and 1.83 °C above average at buoys sites. A significant positive relationship was found between the percentage of coral bleaching that was observed on reef formations and the corresponding HotSpot SST anomaly recorded by both satellite and buoys. These results indicate that the warming observed in the ocean waters was followed by a warming at the reefs. The percentage of bleached corals persisting after the subsidence of the thermal stress, and disease prevalence increased through 2010, after two periods of thermal stress. The in situ temperature anomaly observed during the 2009-2010 El Niño event was equivalent to the anomaly observed during the 1997-1998 El Niño event, explaining similar bleaching intensity. Continued monitoring efforts are necessary to further assess the relationship between bleaching severity and PIRATA SST anomalies and improve the use of this new dataset in future regional bleaching predictions.

ALMA observation of Ceres' Surface Temperature.

Science.gov (United States)

Titus, T. N.; Li, J. Y.; Sykes, M. V.; Ip, W. H.; Lai, I.; Moullet, A.

2016-12-01

Ceres, the largest object in the main asteroid belt, has been mapped by the Dawn spacecraft. The mapping includes measuring surface temperatures using the Visible and Infrared (VIR) spectrometer at high spatial resolution. However, the VIR instrument has a long wavelength cutoff at 5 μm, which prevents the accurate measurement of surface temperatures below 180 K. This restricts temperature determinations to low and mid-latitudes at mid-day. Observations from the Atacama Large Millimeter/submillimeter Array (ALMA) [1], while having lower spatial resolution, are sensitive to the full range of surface temperatures that are expected at Ceres. Forty reconstructed images at 75 km/beam resolution were acquired of Ceres that were consistent with a low thermal inertia surface. The diurnal temperature profiles were compared to the KRC thermal model [2, 3], which has been extensively used for Mars [e.g. 4, 5]. Variations in temperature as a function of local time are observed and are compared to predictions from the KRC model. The model temperatures are converted to radiance (Jy/Steradian) and are corrected for near-surface thermal gradients and limb effects for comparison to observations. Initial analysis is consistent with the presence of near-surface water ice in the north polar region. The edge of the ice table is between 50° and 70° North Latitude, consistent with the enhanced detection of hydrogen by the Dawn GRaND instrument [6]. Further analysis will be presented. This work is supported by the NASA Solar System Observations Program. References: [1] Wootten A. et al. (2015) IAU General Assembly, Meeting #29, #2237199 [2] Kieffer, H. H., et al. (1977) JGR, 82, 4249-4291. [3] Kieffer, Hugh H., (2013) Journal of Geophysical Research: Planets, 118(3), 451-470. [4] Titus, T. N., H. H. Kieffer, and P. N. Christensen (2003) Science, 299, 1048-1051. [5] Fergason, R. L. et al. (2012) Space Sci. Rev, 170, 739-773[6] Prettyman, T. et al. (2016) LPSC 47, #2228.

Analysing Regional Land Surface Temperature Changes by Satellite Data, a Case Study of Zonguldak, Turkey

Science.gov (United States)

Sekertekin, A.; Kutoglu, S.; Kaya, S.; Marangoz, A. M.

2014-12-01

In recent years, climate change is one of the most important problems that the ecological system of the world has been encountering. Global warming and climate change have been studied frequently by all disciplines all over the world and Geomatics Engineering also contributes to such studies by means of remote sensing, global positioning system etc. Monitoring Land Surface Temperature (LST) via remote sensing satellites is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and there are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. Generally three algorithms are used to obtain LST by using Landsat 5 TM data. These algorithms are radiative transfer equation method, single channel method and mono-window algorithm. Radiative transfer equation method is not applicable because during the satellite pass, atmospheric parameters must be measured in-situ. In this research, mono window algorithm was implemented to Landsat 5 TM image. Besides, meteorological data such as humidity and temperature are used in the algorithm. Acquisition date of the image is 28.08.2011 and our study area is Zonguldak, Turkey. High resolution images are used to investigate the relationships between LST and land cover type. As a result of these analyses, area with vegetation cover has approximately 5 ºC lower temperature than the city center and arid land. Because different surface properties like reinforced concrete construction, green zones and sandbank are all together in city center, LST differs about 10 ºC in the city center. The temperature around some places in thermal power plant region Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature because of land cover structure. Thanks to this

Marine heatwaves and optimal temperatures for microbial assemblage activity.

Science.gov (United States)

Joint, Ian; Smale, Dan A

2017-02-01

The response of microbial assemblages to instantaneous temperature change was measured in a seasonal study of the coastal waters of the western English Channel. On 18 occasions between November 1999 and December 2000, bacterial abundance was assessed and temperature responses determined from the incorporation of 3 H leucine, measured in a temperature gradient from 5°C to 38°C. Q 10 values varied, being close to 2 in spring and summer but were >3 in autumn. There was a seasonal pattern in the assemblage optimum temperature (T opt ), which was out of phase with sea surface temperature. In July, highest 3 H-leucine incorporation rates were measured at temperatures that were only 2.8°C greater than ambient sea surface temperature but in winter, T opt was ∼20°C higher than the ambient sea surface temperature. Sea surface temperatures for the adjacent English Channel and Celtic Sea for 1982-2014 have periodically been >3°C higher than climatological mean temperatures. This suggests that discrete periods of anomalously high temperatures might be close to, or exceed, temperatures at which maximum microbial assemblage activity occurs. The frequency and magnitude of marine heatwaves are likely to increase as a consequence of anthropogenic climate change and extreme temperatures may influence the role of bacterial assemblages in biogeochemical processes. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Assimilation of SMOS Brightness Temperatures or Soil Moisture Retrievals into a Land Surface Model

Science.gov (United States)

De Lannoy, Gabrielle J. M.; Reichle, Rolf H.

2016-01-01

Three different data products from the Soil Moisture Ocean Salinity (SMOS) mission are assimilated separately into the Goddard Earth Observing System Model, version 5 (GEOS-5) to improve estimates of surface and root-zone soil moisture. The first product consists of multi-angle, dual-polarization brightness temperature (Tb) observations at the bottom of the atmosphere extracted from Level 1 data. The second product is a derived SMOS Tb product that mimics the data at a 40 degree incidence angle from the Soil Moisture Active Passive (SMAP) mission. The third product is the operational SMOS Level 2 surface soil moisture (SM) retrieval product. The assimilation system uses a spatially distributed ensemble Kalman filter (EnKF) with seasonally varying climatological bias mitigation for Tb assimilation, whereas a time-invariant cumulative density function matching is used for SM retrieval assimilation. All assimilation experiments improve the soil moisture estimates compared to model-only simulations in terms of unbiased root-mean-square differences and anomaly correlations during the period from 1 July 2010 to 1 May 2015 and for 187 sites across the US. Especially in areas where the satellite data are most sensitive to surface soil moisture, large skill improvements (e.g., an increase in the anomaly correlation by 0.1) are found in the surface soil moisture. The domain-average surface and root-zone skill metrics are similar among the various assimilation experiments, but large differences in skill are found locally. The observation-minus-forecast residuals and analysis increments reveal large differences in how the observations add value in the Tb and SM retrieval assimilation systems. The distinct patterns of these diagnostics in the two systems reflect observation and model errors patterns that are not well captured in the assigned EnKF error parameters. Consequently, a localized optimization of the EnKF error parameters is needed to further improve Tb or SM retrieval

Low temperature surface chemistry and nanostructures

Science.gov (United States)

Sergeev, G. B.; Shabatina, T. I.

2002-03-01

The new scientific field of low temperature surface chemistry, which combines the low temperature chemistry (cryochemistry) and surface chemistry approaches, is reviewed in this paper. One of the most exciting achievements in this field of science is the development of methods to create highly ordered hybrid nanosized structures on different organic and inorganic surfaces and to encapsulate nanosized metal particles in organic and polymer matrices. We consider physical and chemical behaviour for the systems obtained by co-condensation of the components vapours on the surfaces cooled down to 4-10 and 70-100 K. In particular the size effect of both types, the number of atoms in the reactive species structure and the thickness of growing co-condensate film, on the chemical activity of the system is analysed in detail. The effect of the internal mechanical stresses on the growing interfacial co-condensate film formation and on the generation of fast (explosive) spontaneous reactions at low temperatures is discussed. The examples of unusual chemical interactions of metal atoms, clusters and nanosized particles, obtained in co-condensate films on the cooled surfaces under different conditions, are presented. The examples of highly ordered surface and volume hybrid nanostructures formation are analysed.

A global climatology of the mesospheric sodium layer from GOMOS data during the 2002–2008 period

Directory of Open Access Journals (Sweden)

D. Fussen

2010-10-01

Full Text Available This paper presents a climatology of the mesospheric sodium layer built from the processing of 7 years of GOMOS data. With respect to preliminary results already published for the year 2003, a more careful analysis was applied to the averaging of occultations inside the climatological bins (10° in latitude-1 month. Also, the slant path absorption lines of the Na doublet around 589 nm shows evidence of partial saturation that was responsible for an underestimation of the Na concentration in our previous results. The sodium climatology has been validated with respect to the Fort Collins lidar measurements and, to a lesser extent, to the OSIRIS 2003–2004 data. Despite the important natural sodium variability, we have shown that the Na vertical column has a marked semi-annual oscillation at low latitudes that merges into an annual oscillation in the polar regions,a spatial distribution pattern that was unreported so far. The sodium layer seems to be clearly influenced by the mesospheric global circulation and the altitude of the layer shows clear signs of subsidence during polar winter. The climatology has been parameterized by time-latitude robust fits to allow for easy use. Taking into account the non-linearity of the transmittance due to partial saturation, an experimental approach is proposed to derive mesospheric temperatures from limb remote sounding measurements.

Tower Mesonetwork Climatology and Interactive Display Tool

Science.gov (United States)

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

2004-01-01

Forecasters at the 45th Weather Squadron and Spaceflight Meteorology Group use data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria, and issue and verify forecasts for ground operations. Systematic biases in these parameters could adversely affect an analysis, forecast, or verification. Also, substantial geographical variations in temperature and wind speed can occur under specific wind directions. To address these concerns, the Applied Meteorology Unit (AMU) developed a climatology of temperatures and winds from the tower network, and identified the geographical variation and significant tower biases. The mesoclimate is largely driven by the complex land-water interfaces across KSC/CCAFS. Towers with close proximity to water typically had much warmer nocturnal temperatures and higher wind speeds throughout the year. The strongest nocturnal wind speeds occurred from October to March whereas the strongest mean daytime wind speeds occurred from February to May. These results of this project can be viewed by forecasters through an interactive graphical user interface developed by the AMU. The web-based interface includes graphical and map displays of mean, standard deviation, bias, and data availability for any combination of towers, variables, months, hours, and wind directions.

Eye surface temperature detects stress response in budgerigars (Melopsittacus undulatus).

Science.gov (United States)

Ikkatai, Yuko; Watanabe, Shigeru

2015-08-05

Previous studies have suggested that stressors not only increase body core temperature but also body surface temperature in many animals. However, it remains unclear whether surface temperature could be used as an alternative to directly measure body core temperature, particularly in birds. We investigated whether surface temperature is perceived as a stress response in budgerigars. Budgerigars have been used as popular animal models to investigate various neural mechanisms such as visual perception, vocal learning, and imitation. Developing a new technique to understand the basic physiological mechanism would help neuroscience researchers. First, we found that cloacal temperature correlated with eye surface temperature. Second, eye surface temperature increased after handling stress. Our findings suggest that eye surface temperature is closely related to cloacal temperature and that the stress response can be measured by eye surface temperature in budgerigars.

Performance analysis of PV panel under varying surface temperature

Directory of Open Access Journals (Sweden)

Kumar Tripathi Abhishek

2018-01-01

Full Text Available The surface temperature of PV panel has an adverse impact on its performance. The several electrical parameters of PV panel, such as open circuit voltage, short circuit current, power output and fill factor depends on the surface temperature of PV panel. In the present study, an experimental work was carried out to investigate the influence of PV panel surface temperature on its electrical parameters. The results obtained from this experimental study show a significant reduction in the performance of PV panel with an increase in panel surface temperature. A 5W PV panel experienced a 0.4% decrease in open circuit voltage for every 1°C increase in panel surface temperature. Similarly, there was 0.6% and 0.32% decrease in maximum power output and in fill factor, respectively, for every 1°C increase in panel surface temperature. On the other hand, the short circuit current increases with the increase in surface temperature at the rate of 0.09%/°C.

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)

Assessment of broiler surface temperature variation when exposed to different air temperatures

Directory of Open Access Journals (Sweden)

GR Nascimento

2011-12-01

Full Text Available This study was conducted to determine the effect of the air temperature variation on the mean surface temperature (MST of 7- to 35-day-old broiler chickens using infrared thermometry to estimate MST, and to study surface temperature variation of the wings, head, legs, back and comb as affected by air temperature and broiler age. One hundred Cobb® broilers were used in the experiment. Starting on day 7, 10 birds were weekly selected at random, housed in an environmental chamber and reared under three distinct temperatures (18, 25 and 32 ºC to record their thermal profile using an infrared thermal camera. The recorded images were processed to estimate MST by selecting the whole area of the bird within the picture and comparing it with the values obtained using selected equations in literature, and to record the surface temperatures of the body parts. The MST estimated by infrared images were not statistically different (p > 0.05 from the values obtained by the equations. MST values significantly increased (p < 0.05 when the air temperature increased, but were not affected by bird age. However, age influenced the difference between MST and air temperature, which was highest on day 14. The technique of infrared thermal image analysis was useful to estimate the mean surface temperature of broiler chickens.

Climatology of sea breezes along the Red Sea coast of Saudi Arabia

KAUST Repository

Khan, Basit

2018-04-25

Long-term near-surface observations from five coastal stations, high-resolution model data from Modern Era Retrospective-Analysis for Research and Applications (MERRA) and high-resolution daily sea surface temperature (SST) from National Ocean and Atmospheric Administration (NOAA) are used to investigate the climatology of sea breezes over the eastern side of the Red Sea region. Results show existence of separate sea breeze systems along different segments of the Red Sea coastline. Based on the physical character and synoptic influences, sea breezes in the Red Sea are broadly divided into three regions: the north and the middle Red Sea (NMRS), the Red Sea convergence zone (RSCZ) and the southern Red Sea (SRS) regions. On average, sea breezes developed on 67% of days of the 10-year study period. Although sea breezes occur almost all year, this mesoscale phenomenon is most frequent from May to October (78% of the total sea breeze days). The sea breeze frequency increases from north to south (equatorwards), and sea breeze characteristics appear to vary both temporally and spatially. In addition to land-sea thermal differential, coastline shape, latitude and topography, the prevailing northwesterly at NMRS region, the convergence of northwesterly and southeasterly wind system at RSCZ region and the northeast and southwest monsoon at SRS region play an important role in defining the sea breeze characteristics over the Red Sea.

Regional and applied climatology-contributions

International Nuclear Information System (INIS)

Endlicher, W.; Gossmann, H.

1991-01-01

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) [de

Surface energy balances of three general circulation models: Current climate and response to increasing atmospheric CO2

International Nuclear Information System (INIS)

Gutowski, W.J.; Gutzler, D.S.; Portman, D.; Wang, W.C.

1988-04-01

The surface energy balance simulated by state-of-the-art general circulation models at GFDL, GISS and NCAR for climates with current levels of atmospheric CO 2 concentration (control climate) and with twice the current levels. The work is part of an effort sponsored by the US Department of Energy to assess climate simulations produced by these models. The surface energy balance enables us to diagnose differences between models in surface temperature climatology and sensitivity to doubling CO 2 in terms of the processes that control surface temperature. Our analysis compares the simulated balances by averaging the fields of interest over a hierarchy of spatial domains ranging from the entire globe down to regions a few hundred kilometers across

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.

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

Temperature sensitive surfaces and methods of making same

Science.gov (United States)

Liang, Liang [Richland, WA; Rieke, Peter C [Pasco, WA; Alford, Kentin L [Pasco, WA

2002-09-10

Poly-n-isopropylacrylamide surface coatings demonstrate the useful property of being able to switch charateristics depending upon temperature. More specifically, these coatings switch from being hydrophilic at low temperature to hydrophobic at high temperature. Research has been conducted for many years to better characterize and control the properties of temperature sensitive coatings. The present invention provides novel temperature sensitive coatings on articles and novel methods of making temperature sensitive coatings that are disposed on the surfaces of various articles. These novel coatings contain the reaction products of n-isopropylacrylamide and are characterized by their properties such as advancing contact angles. Numerous other characteristics such as coating thickness, surface roughness, and hydrophilic-to-hydrophobic transition temperatures are also described. The present invention includes articles having temperature-sensitve coatings with improved properties as well as improved methods for forming temperature sensitive coatings.

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

Climatology of nocturnal low-level jets over North Africa and implications for modeling mineral dust emission.

Science.gov (United States)

Fiedler, S; Schepanski, K; Heinold, B; Knippertz, P; Tegen, I

2013-06-27

[1] This study presents the first climatology for the dust emission amount associated with Nocturnal Low-Level Jets (NLLJs) in North Africa. These wind speed maxima near the top of the nocturnal boundary layer can generate near-surface peak winds due to shear-driven turbulence in the course of the night and the NLLJ breakdown during the following morning. The associated increase in the near-surface wind speed is a driver for mineral dust emission. A new detection algorithm for NLLJs is presented and used for a statistical assessment of NLLJs in 32 years of ERA-Interim reanalysis from the European Centre for Medium-Range Weather Forecasts. NLLJs occur in 29% of the nights in the annual and spatial mean. The NLLJ climatology shows a distinct annual cycle with marked regional differences. Maxima of up to 80% NLLJ frequency are found where low-level baroclinicity and orographic channels cause favorable conditions, e.g., over the Bodélé Depression, Chad, for November-February and along the West Saharan and Mauritanian coast for April-September. Downward mixing of NLLJ momentum to the surface causes 15% of mineral dust emission in the annual and spatial mean and can be associated with up to 60% of the total dust amount in specific areas, e.g., the Bodélé Depression and south of the Hoggar-Tibesti Channel. The sharp diurnal cycle underlines the importance of using wind speed information with high temporal resolution as driving fields for dust emission models. Citation: Fiedler, S., K. Schepanski, B. Heinold, P. Knippertz, and I. Tegen (2013), Climatology of nocturnal low-level jets over North Africa and implications for modeling mineral dust emission, J. Geophys. Res. Atmos., 118, 6100-6121, doi:10.1002/jgrd.50394.

Satellite-derived ice data sets no. 2: Arctic monthly average microwave brightness temperatures and sea ice concentrations, 1973-1976

Science.gov (United States)

Parkinson, C. L.; Comiso, J. C.; Zwally, H. J.

1987-01-01

A summary data set for four years (mid 70's) of Arctic sea ice conditions is available on magnetic tape. The data include monthly and yearly averaged Nimbus 5 electrically scanning microwave radiometer (ESMR) brightness temperatures, an ice concentration parameter derived from the brightness temperatures, monthly climatological surface air temperatures, and monthly climatological sea level pressures. All data matrices are applied to 293 by 293 grids that cover a polar stereographic map enclosing the 50 deg N latitude circle. The grid size varies from about 32 X 32 km at the poles to about 28 X 28 km at 50 deg N. The ice concentration parameter is calculated assuming that the field of view contains only open water and first-year ice with an ice emissivity of 0.92. To account for the presence of multiyear ice, a nomogram is provided relating the ice concentration parameter, the total ice concentration, and the fraction of the ice cover which is multiyear ice.

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...

Long-term changes in sea surface temperatures

International Nuclear Information System (INIS)

Parker, D.E.

1994-01-01

Historical observations of sea surface temperature since 1856 have been improved by applying corrections to compensate for the predominant use of uninsulated or partly insulated buckets until the Second World War. There are large gaps in coverage in the late nineteenth century and around the two world wars, but a range of statistical techniques suggest that these gaps do not severely prejudice estimates of global and regional climatic change. Nonetheless, to improve the analysis on smaller scales, many unused historical data are to be digitized and incorporated. For recent years, satellite-based sea surface temperatures have improved the coverage, after adjustments for their biases relative to in situ data. An initial version of a nominally globally complete sea ice and interpolated sea surface temperature data set, beginning in 1871, has been created for use in numerical simulations of recent climate. Long time series of corrected regional, hemispheric, and global sea surface temperatures are mostly consistent with corresponding night marine air temperature series, and confirm the regionally specific climatic changes portrayed in the Scientific Assessments of the intergovernmental Panel on Climate Change. The observations also show an El Nino-like oscillation on bidecadal and longer time scales

Evaluation of global climate models for Indian monsoon climatology

International Nuclear Information System (INIS)

Kodra, Evan; Ganguly, Auroop R; Ghosh, Subimal

2012-01-01

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)

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.

Planetary-scale circulations in the presence of climatological and wave-induced heating

Science.gov (United States)

Salby, Murry L; Garcia, Rolando R.; Hendon, Harry H.

1994-01-01

Interaction between the large-scale circulation and the convective pattern is investigated in a coupled system governed by the linearized primitive equations. Convection is represented in terms of two components of heating: A 'climatological component' is prescribed stochastically to represent convection that is maintained by fixed distributions of land and sea and sea surface temperature (SST). An 'induced component' is defined in terms of the column-integrated moisture flux convergence to represent convection that is produced through feedback with the circulation. Each component describes the envelope organizing mesoscale convective activity. As SST on the equator is increased, induced heating amplifies in the gravest zonal wavenumbers at eastward frequencies, where positive feedback offsets dissipation. Under barotropic stratification, a critical SST of 29.5 C results in positive feedback exactly cancelling dissipation in wavenumber 1 for an eastward phase speed of 6 m/s. Sympathetic interaction between the circulation and the induced heating is the basis for 'frictional wave-Conditional Instability of the Second Kind (CISK)', which is distinguished from classical wave-CISK by rendering the gravest zonal dimensions most unstable. Under baroclinic stratification, the coupled system exhibits similar behavior. The critical SST is only 26.5 C for conditions representative of equinox, but in excess of 30 C for conditions representative of solstice. Having the form of an unsteady Walker circulation, the disturbance produced by frictional wave-CISK compares favorably with the observed life cycle of the Madden-Julian oscillation (MJO). SST above the critical value produces an amplifying disturbance in which enhanced convection coincides with upper-tropospheric westerlies and is positively correlated with temperature and surface convergence. Conversely, SST below the critical value produces a decaying disturbance in which enhanced convection coincides with upper

NOAA Global Surface Temperature Dataset, Version 4.0

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Global Surface Temperature Dataset (NOAAGlobalTemp) is derived from two independent analyses: the Extended Reconstructed Sea Surface Temperature (ERSST)...

Temperature minima in the average thermal structure of the middle mesosphere (70 - 80 km) from analysis of 40- to 92-km SME global temperature profiles

Science.gov (United States)

Clancy, R. Todd; Rusch, David W.; Callan, Michael T.

1994-01-01

Global temperatures have been derived for the upper stratosphere and mesosphere from analysis of Solar Mesosphere Explorer (SME) limb radiance profiles. The SME temperature represent fixed local time observations at 1400 - 1500 LT, with partial zonal coverage of 3 - 5 longitudes per day over the 1982-1986 period. These new SME temperatures are compared to the COSPAR International Ionosphere Reference Atmosphere 86 (CIRA 86) climatology (Fleming et al., 1990) as well as stratospheric and mesospheric sounder (SAMS); Barnett and Corney, 1984), National Meteorological Center (NMC); (Gelman et al., 1986), and individual lidar and rocket observations. Significant areas of disagreement between the SME and CIRA 86 mesospheric temperatures are 10 K warmer SME temperatures at altitudes above 80 km. The 1981-1982 SAMS temperatures are in much closer agreement with the SME temperatures between 40 and 75 km. Although much of the SME-CIRA 86 disagreement probably stems from the poor vertical resolution of the observations comprising the CIRA 86 modelm, some portion of the differences may reflect 5- to 10-year temporal variations in mesospheric temperatures. The CIRA 86 climatology is based on 1973-1978 measurements. Relatively large (1 K/yr) 5- to 10-year trends in temperatures as functions of longitude, latitude, and altitude have been observed for both the upper stratosphere (Clancy and Rusch, 1989a) and mesosphere (Clancy and Rusch, 1989b; Hauchecorne et al., 1991). The SME temperatures also exhibit enhanced amplitudes for the semiannual oscillation (SAO) of upper mesospheric temperatures at low latitudes, which are not evident in the CIRA 86 climatology. The so-called mesospheric `temperature inversions' at wintertime midlatitudes, which have been observed by ground-based lidar (Hauschecorne et al., 1987) and rocket in situ measurements (Schmidlin, 1976), are shown to be a climatological aspect of the mesosphere, based on the SME observations.

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.

Temperature Dependence of Arn+ Cluster Backscattering from Polymer Surfaces: a New Method to Determine the Surface Glass Transition Temperature.

Science.gov (United States)

Poleunis, Claude; Cristaudo, Vanina; Delcorte, Arnaud

2018-01-01

In this work, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to study the intensity variations of the backscattered Ar n + clusters as a function of temperature for several amorphous polymer surfaces (polyolefins, polystyrene, and polymethyl methacrylate). For all these investigated polymers, our results show a transition of the ratio Ar 2 + /(Ar 2 + + Ar 3 + ) when the temperature is scanned from -120 °C to +125 °C (the exact limits depend on the studied polymer). This transition generally spans over a few tens of degrees and the temperature of the inflection point of each curve is always lower than the bulk glass transition temperature (T g ) reported for the considered polymer. Due to the surface sensitivity of the cluster backscattering process (several nanometers), the presented analysis could provide a new method to specifically evaluate a surface transition temperature of polymers, with the same lateral resolution as the gas cluster beam. Graphical abstract ᅟ.

Extended Reconstructed Sea Surface Temperature (ERSST), Version 4

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature analysis on a 2x2 degree grid derived from the...

Surface Temperature Data Analysis

Science.gov (United States)

Hansen, James; Ruedy, Reto

2012-01-01

Small global mean temperature changes may have significant to disastrous consequences for the Earth's climate if they persist for an extended period. Obtaining global means from local weather reports is hampered by the uneven spatial distribution of the reliably reporting weather stations. Methods had to be developed that minimize as far as possible the impact of that situation. This software is a method of combining temperature data of individual stations to obtain a global mean trend, overcoming/estimating the uncertainty introduced by the spatial and temporal gaps in the available data. Useful estimates were obtained by the introduction of a special grid, subdividing the Earth's surface into 8,000 equal-area boxes, using the existing data to create virtual stations at the center of each of these boxes, and combining temperature anomalies (after assessing the radius of high correlation) rather than temperatures.

Developing MODIS-based cloud climatologies to aid species distribution modeling and conservation activities

Directory of Open Access Journals (Sweden)

Michael William Douglas

2016-10-01

Full Text Available WorldClim (Hijmans et al. 2005 has been the de-facto source of basic climatological analyses for most species distribution modeling research and conservation science applications because of its global coverage and fine (<1 km spatial resolution.  However, it has been recognized since its development that there are limitations in data-poor regions, especially with regard to the precipitation analyses.  Here we describe procedures to develop a satellite-based daytime cloudiness climatology that better reflects the variations in vegetation cover in many regions of the globe than do the WorldClim precipitation products.  Moderate Resolution Imaging Spectroradiometer (MODIS imagery from the National Aeronautics and Space Administration (NASA Terra and Aqua sun-synchronous satellites have recently been used to develop multi-year climatologies of cloudiness.  Several procedures exist for developing such climatologies.  We first discuss a simple procedure that uses brightness thresholds to identify clouds.  We compare these results with those from a more complex procedure: the MODIS Cloud Mask product, recently averaged into climatological products by Wilson and Jetz (2016.  We discuss advantages and limitations of both approaches.  We also speculate on further work that will be needed to improve the usefulness of these MODIS-based climatologies of cloudiness. Despite limitations of current MODIS-based climatology products, they have the potential to greatly improve our understanding of the distribution of biota across the globe.  We show examples from oceanic islands and arid coastlines in the subtropics and tropics where the MODIS products should be of special value in predicting the observed vegetation cover.  Some important applications of reliable climatologies based on MODIS imagery products will include 1 helping to restore long-degraded cloud-impacted environments; 2 improving estimations of the spatial distribution of cloud

Improving Frozen Precipitation Density Estimation in Land Surface Modeling

Science.gov (United States)

Sparrow, K.; Fall, G. M.

2017-12-01

The Office of Water Prediction (OWP) produces high-value water supply and flood risk planning information through the use of operational land surface modeling. Improvements in diagnosing frozen precipitation density will benefit the NWS's meteorological and hydrological services by refining estimates of a significant and vital input into land surface models. A current common practice for handling the density of snow accumulation in a land surface model is to use a standard 10:1 snow-to-liquid-equivalent ratio (SLR). Our research findings suggest the possibility of a more skillful approach for assessing the spatial variability of precipitation density. We developed a 30-year SLR climatology for the coterminous US from version 3.22 of the Daily Global Historical Climatology Network - Daily (GHCN-D) dataset. Our methods followed the approach described by Baxter (2005) to estimate mean climatological SLR values at GHCN-D sites in the US, Canada, and Mexico for the years 1986-2015. In addition to the Baxter criteria, the following refinements were made: tests were performed to eliminate SLR outliers and frequent reports of SLR = 10, a linear SLR vs. elevation trend was fitted to station SLR mean values to remove the elevation trend from the data, and detrended SLR residuals were interpolated using ordinary kriging with a spherical semivariogram model. The elevation values of each station were based on the GMTED 2010 digital elevation model and the elevation trend in the data was established via linear least squares approximation. The ordinary kriging procedure was used to interpolate the data into gridded climatological SLR estimates for each calendar month at a 0.125 degree resolution. To assess the skill of this climatology, we compared estimates from our SLR climatology with observations from the GHCN-D dataset to consider the potential use of this climatology as a first guess of frozen precipitation density in an operational land surface model. The difference in

Ozone climatology over western Mediterranean Sea

International Nuclear Information System (INIS)

Pibiri, G.; Randaccio, P.; Serra, A.; Sollai, A.

1984-01-01

A preliminary climatology of atmospheric ozone over Western Mediterranean Sea is given by analysis of the upper observations of O 3 carried out at Cagliari-Elmas station from 1968 to 1976. Some peculiarities are here illustrated and discussed

Modelling global fresh surface water temperature

NARCIS (Netherlands)

Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

2011-01-01

Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

Alleviating tropical Atlantic sector biases in the Kiel climate model by enhancing horizontal and vertical atmosphere model resolution: climatology and interannual variability

Science.gov (United States)

Harlaß, Jan; Latif, Mojib; Park, Wonsun

2018-04-01

We investigate the quality of simulating tropical Atlantic (TA) sector climatology and interannual variability in integrations of the Kiel climate model (KCM) with varying atmosphere model resolution. The ocean model resolution is kept fixed. A reasonable simulation of TA sector annual-mean climate, seasonal cycle and interannual variability can only be achieved at sufficiently high horizontal and vertical atmospheric resolution. Two major reasons for the improvements are identified. First, the western equatorial Atlantic westerly surface wind bias in spring can be largely eliminated, which is explained by a better representation of meridional and especially vertical zonal momentum transport. The enhanced atmospheric circulation along the equator in turn greatly improves the thermal structure of the upper equatorial Atlantic with much reduced warm sea surface temperature (SST) biases. Second, the coastline in the southeastern TA and steep orography are better resolved at high resolution, which improves wind structure and in turn reduces warm SST biases in the Benguela upwelling region. The strongly diminished wind and SST biases at high atmosphere model resolution allow for a more realistic latitudinal position of the intertropical convergence zone. Resulting stronger cross-equatorial winds, in conjunction with a shallower thermocline, enable a rapid cold tongue development in the eastern TA in boreal spring. This enables simulation of realistic interannual SST variability and its seasonal phase locking in the KCM, which primarily is the result of a stronger thermocline feedback. Our findings suggest that enhanced atmospheric resolution, both vertical and horizontal, could be a key to achieving more realistic simulation of TA climatology and interannual variability in climate models.

Venus-Earth-Mars: comparative climatology and the search for life in the solar system.

Science.gov (United States)

Launius, Roger D

2012-09-19

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.

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

Science.gov (United States)

Launius, Roger D.

2012-01-01

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. PMID:25371106

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.

High-frequency fluctuations of surface temperatures in an urban environment

Science.gov (United States)

Christen, Andreas; Meier, Fred; Scherer, Dieter

2012-04-01

This study presents an attempt to resolve fluctuations in surface temperatures at scales of a few seconds to several minutes using time-sequential thermography (TST) from a ground-based platform. A scheme is presented to decompose a TST dataset into fluctuating, high-frequency, and long-term mean parts. To demonstrate the scheme's application, a set of four TST runs (day/night, leaves-on/leaves-off) recorded from a 125-m-high platform above a complex urban environment in Berlin, Germany is used. Fluctuations in surface temperatures of different urban facets are measured and related to surface properties (material and form) and possible error sources. A number of relationships were found: (1) Surfaces with surface temperatures that were significantly different from air temperature experienced the highest fluctuations. (2) With increasing surface temperature above (below) air temperature, surface temperature fluctuations experienced a stronger negative (positive) skewness. (3) Surface materials with lower thermal admittance (lawns, leaves) showed higher fluctuations than surfaces with high thermal admittance (walls, roads). (4) Surface temperatures of emerged leaves fluctuate more compared to trees in a leaves-off situation. (5) In many cases, observed fluctuations were coherent across several neighboring pixels. The evidence from (1) to (5) suggests that atmospheric turbulence is a significant contributor to fluctuations. The study underlines the potential of using high-frequency thermal remote sensing in energy balance and turbulence studies at complex land-atmosphere interfaces.

The EUSTACE project: delivering global, daily information on surface air temperature

Science.gov (United States)

Ghent, D.; Rayner, N. A.

2017-12-01

Day-to-day variations in surface air temperature affect society in many ways; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, in the EUSTACE project (2015-2018, https://www.eustaceproject.eu) we have developed an understanding of the relationships between traditional (land and marine) surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. Here we discuss the science needed to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types. Information contained in the satellite retrievals is used to create globally-complete fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place. This includes developing new "Big Data" analysis methods as the data volumes involved are considerable. We will present recent progress along this road in the EUSTACE project, i.e.: • identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; • estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; • using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras. Information will also be given on how interested users can become involved.

Do Aphids Alter Leaf Surface Temperature Patterns During Early Infestation?

Directory of Open Access Journals (Sweden)

Thomas Cahon

2018-03-01

Full Text Available Arthropods at the surface of plants live in particular microclimatic conditions that can differ from atmospheric conditions. The temperature of plant leaves can deviate from air temperature, and leaf temperature influences the eco-physiology of small insects. The activity of insects feeding on leaf tissues, may, however, induce changes in leaf surface temperatures, but this effect was only rarely demonstrated. Using thermography analysis of leaf surfaces under controlled environmental conditions, we quantified the impact of presence of apple green aphids on the temperature distribution of apple leaves during early infestation. Aphids induced a slight change in leaf surface temperature patterns after only three days of infestation, mostly due to the effect of aphids on the maximal temperature that can be found at the leaf surface. Aphids may induce stomatal closure, leading to a lower transpiration rate. This effect was local since aphids modified the configuration of the temperature distribution over leaf surfaces. Aphids were positioned at temperatures near the maximal leaf surface temperatures, thus potentially experiencing the thermal changes. The feedback effect of feeding activity by insects on their host plant can be important and should be quantified to better predict the response of phytophagous insects to environmental changes.

High-resolution nested model simulations of the climatological circulation in the southeastern Mediterranean Sea

Directory of Open Access Journals (Sweden)

S. Brenner

2003-01-01

Full Text Available As part of the Mediterranean Forecasting System Pilot Project (MFSPP we have implemented a high-resolution (2 km horizontal grid, 30 sigma levels version of the Princeton Ocean Model for the southeastern corner of the Mediterranean Sea. The domain extends 200 km offshore and includes the continental shelf and slope, and part of the open sea. The model is nested in an intermediate resolution (5.5 km grid model that covers the entire Levantine, Ionian, and Aegean Sea. The nesting is one way so that velocity, temperature, and salinity along the boundaries are interpolated from the relevant intermediate model variables. An integral constraint is applied so that the net mass flux across the open boundaries is identical to the net flux in the intermediate model. The model is integrated for three perpetual years with surface forcing specified from monthly mean climatological wind stress and heat fluxes. The model is stable and spins up within the first year to produce a repeating seasonal cycle throughout the three-year integration period. While there is some internal variability evident in the results, it is clear that, due to the relatively small domain, the results are strongly influenced by the imposed lateral boundary conditions. The results closely follow the simulation of the intermediate model. The main improvement is in the simulation over the narrow shelf region, which is not adequately resolved by the coarser grid model. Comparisons with direct current measurements over the shelf and slope show reasonable agreement despite the limitations of the climatological forcing. The model correctly simulates the direction and the typical speeds of the flow over the shelf and slope, but has difficulty properly re-producing the seasonal cycle in the speed.Key words. Oceanography: general (continental shelf processes; numerical modelling; ocean prediction

Long-term trend analysis and climatology of tropical cirrus clouds using 16 years of lidar data set over Southern India

Science.gov (United States)

Pandit, A. K.; Gadhavi, H. S.; Venkat Ratnam, M.; Raghunath, K.; Rao, S. V. B.; Jayaraman, A.

2015-12-01

Sixteen-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 7 and a 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 the differences 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 a higher 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. The mid-cloud altitude of sub-visible cirrus clouds is found to be increasing at the rate of 41 ± 21 m year-1. Statistically significant decrease in optical thickness of sub-visible and thick cirrus clouds is observed. Also, the fraction of sub-visible cirrus cloud is found to have increased by 9 % in the last 16 years (1998 to 2013). This increase is mainly compensated by a 7 % decrease in thin cirrus cloud fraction. This has implications for the temperature and water vapour budget in the tropical tropopause layer.

Wind Climate Analyses for SRTC's Central Climatology Site

International Nuclear Information System (INIS)

Weber, A.H.

2003-01-01

This report was written to present climatological summaries of the wind data at the Central Climatology (CC) tower in a convenient format and to point out some features of the wind speed and direction that have not been widely appreciated in the past. Short-term (two-week) wind roses provide a means to demonstrate the temporal and spatial relationships that wind speed and direction undergo using a ten-year database from the CC tower. These relationships are best demonstrated by examining the figures provided in this report or looking at loops of computer-generated images provided by the authors

Recent trends in sea surface temperature off Mexico

NARCIS (Netherlands)

Lluch-Cota, S.E.; Tripp-Valdéz, M.; Lluch-Cota, D.B.; Lluch-Belda, D.; Verbesselt, J.; Herrera-Cervantes, H.; Bautista-Romero, J.

2013-01-01

Changes in global mean sea surface temperature may have potential negative implications for natural and socioeconomic systems; however, measurements to predict trends in different regions have been limited and sometimes contradictory. In this study, an assessment of sea surface temperature change

Estimating surface turbulent heat fluxes from land surface temperature and soil moisture using the particle batch smoother

Science.gov (United States)

Lu, Yang; Dong, Jianzhi; Steele-Dunne, Susan; van de Giesen, Nick

2016-04-01

This study is focused on estimating surface sensible and latent heat fluxes from land surface temperature (LST) time series and soil moisture observations. Surface turbulent heat fluxes interact with the overlying atmosphere and play a crucial role in meteorology, hydrology and other climate-related fields, but in-situ measurements are costly and difficult. It has been demonstrated that the time series of LST contains information of energy partitioning and that surface turbulent heat fluxes can be determined from assimilation of LST. These studies are mainly based on two assumptions: (1) a monthly value of bulk heat transfer coefficient under neutral conditions (CHN) which scales the sum of the fluxes, and (2) an evaporation fraction (EF) which stays constant during the near-peak hours of the day. Previous studies have applied variational and ensemble approaches to this problem. Here the newly developed particle batch smoother (PBS) algorithm is adopted to test its capability in this application. The PBS can be seen as an extension of the standard particle filter (PF) in which the states and parameters within a fix window are updated in a batch using all observations in the window. The aim of this study is two-fold. First, the PBS is used to assimilate only LST time series into the force-restore model to estimate fluxes. Second, a simple soil water transfer scheme is introduced to evaluate the benefit of assimilating soil moisture observations simultaneously. The experiments are implemented using the First ISLSCP (International Satellite Land Surface Climatology Project) (FIFE) data. It is shown that the restored LST time series using PBS agrees very well with observations, and that assimilating LST significantly improved the flux estimation at both daily and half-hourly time scales. When soil moisture is introduced to further constrain EF, the accuracy of estimated EF is greatly improved. Furthermore, the RMSEs of retrieved fluxes are effectively reduced at both

Climatology of winter transition days for the contiguous USA, 1951-2007

Science.gov (United States)

Hondula, David M.; Davis, Robert E.

2011-01-01

In middle and high latitudes, climate change could impact the frequency and characteristics of frontal passages. Although transitions between air masses are significant features of the general circulation that influence human activities and other surface processes, they are much more difficult to objectively identify than single variables like temperature or even extreme events like fires, droughts, and floods. The recently developed Spatial Synoptic Classification (SSC) provides a fairly objective means of identifying frontal passages. In this research, we determine the specific meteorological patterns represented by the SSC's Transition category, a "catch-all" group that attempts to identify those days that cannot be characterized as a single, homogeneous air mass type. The result is a detailed transition climatology for the continental USA. We identify four subtypes of the Transition category based on intra-day sea level pressure change and dew point temperature change. Across the contiguous USA, most transition days are identified as cold fronts and warm fronts during the winter season. Among the two less common subtypes, transition days in which the dew point temperature and pressure both rise are more frequently observed across the western states, and days in which both variables fall are more frequently observed in coastal regions. The relative frequencies of wintertime warm and cold fronts have changed over the period 1951-2007. Relative cold front frequency has significantly increased in the Northeast and Midwest regions, and warm front frequencies have declined in the Midwest, Rocky Mountain, and Pacific Northwest regions. The overall shift toward cold fronts and away from warm fronts across the northern USA arises from a combination of an enhanced ridge over western North America and a northward shift of storm tracks throughout the mid-latitudes. These results are consistent with projections of climate change associated with elevated greenhouse gas

Temperature-dependent surface density of alkylthiol monolayers on gold nanocrystals

Science.gov (United States)

Liu, Xuepeng; Lu, Pin; Zhai, Hua; Wu, Yucheng

2018-03-01

Atomistic molecular dynamics (MD) simulations are performed to study the surface density of passivating monolayers of alkylthiol chains on gold nanocrystals at temperatures ranging from 1 to 800 K. The results show that the surface density of alkylthiol monolayer reaches a maximum value at near room temperature (200-300 K), while significantly decreases with increasing temperature in the higher temperature region (> 300 {{K}}), and slightly decreases with decreasing temperature at low temperature (< 200 {{K}}). We find that the temperature dependence of surface ligand density in the higher temperature region is attributed to the substantial ligand desorption induced by the thermal fluctuation, while that at low temperature results from the reduction in entropy caused by the change in the ordering of passivating monolayer. These results are expected helpful to understand the temperature-dependent surface coverage of gold nanocrystals.

A physically based model of global freshwater surface temperature

Science.gov (United States)

van Beek, Ludovicus P. H.; Eikelboom, Tessa; van Vliet, Michelle T. H.; Bierkens, Marc F. P.

2012-09-01

Temperature determines a range of physical properties of water and exerts a strong control on surface water biogeochemistry. Thus, in freshwater ecosystems the thermal regime directly affects the geographical distribution of aquatic species through their growth and metabolism and indirectly through their tolerance to parasites and diseases. Models used to predict surface water temperature range between physically based deterministic models and statistical approaches. Here we present the initial results of a physically based deterministic model of global freshwater surface temperature. The model adds a surface water energy balance to river discharge modeled by the global hydrological model PCR-GLOBWB. In addition to advection of energy from direct precipitation, runoff, and lateral exchange along the drainage network, energy is exchanged between the water body and the atmosphere by shortwave and longwave radiation and sensible and latent heat fluxes. Also included are ice formation and its effect on heat storage and river hydraulics. We use the coupled surface water and energy balance model to simulate global freshwater surface temperature at daily time steps with a spatial resolution of 0.5° on a regular grid for the period 1976-2000. We opt to parameterize the model with globally available data and apply it without calibration in order to preserve its physical basis with the outlook of evaluating the effects of atmospheric warming on freshwater surface temperature. We validate our simulation results with daily temperature data from rivers and lakes (U.S. Geological Survey (USGS), limited to the USA) and compare mean monthly temperatures with those recorded in the Global Environment Monitoring System (GEMS) data set. Results show that the model is able to capture the mean monthly surface temperature for the majority of the GEMS stations, while the interannual variability as derived from the USGS and NOAA data was captured reasonably well. Results are poorest for

Northwest Atlantic Regional Climatology (NCEI Accession 0155889)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — To provide an improved oceanographic foundation and reference for multi-disciplinary studies of the Northwest Atlantic Ocean, NCEI Regional Climatology Team...

Climatology of the Savannah River Plant site

International Nuclear Information System (INIS)

Hoel, D.D.

1984-06-01

This document contains information on the climatological characteristics of the SRP site, as well as information on relative concentrations and deposition for specific radionuclides. 42 references, 42 figures, 45 tables

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

International Nuclear Information System (INIS)

Stucki, Peter; Rickli, Ralph; Broennimann, Stefan; Martius, Olivia; Wanner, Heinz; Bern Univ.; Grebner, Dietmar; Luterbacher, Juerg

2012-01-01

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 20 th Century Reanalysis (20CR) data. Extreme floods are determined by the 95 th 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 ≥ 98 th 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.)

Efflorescent sulfates from Baia Sprie mining area (Romania) — Acid mine drainage and climatological approach

International Nuclear Information System (INIS)

Buzatu, Andrei; Dill, Harald G.; Buzgar, Nicolae; Damian, Gheorghe; Maftei, Andreea Elena; Apopei, Andrei Ionuț

2016-01-01

The Baia Sprie epithermal system, a well-known deposit for its impressive mineralogical associations, shows the proper conditions for acid mine drainage and can be considered a general example for affected mining areas around the globe. Efflorescent samples from the abandoned open pit Minei Hill have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and near-infrared (NIR) spectrometry. The identified phases represent mostly iron sulfates with different hydration degrees (szomolnokite, rozenite, melanterite, coquimbite, ferricopiapite), Zn and Al sulfates (gunningite, alunogen, halotrichite). The samples were heated at different temperatures in order to establish the phase transformations among the studied sulfates. The dehydration temperatures and intermediate phases upon decomposition were successfully identified for each of mineral phases. Gunningite was the single sulfate that showed no transformations during the heating experiment. All the other sulfates started to dehydrate within the 30–90 °C temperature range. The acid mine drainage is the main cause for sulfates formation, triggered by pyrite oxidation as the major source for the abundant iron sulfates. Based on the dehydration temperatures, the climatological interpretation indicated that melanterite formation and long-term presence is related to continental and temperate climates. Coquimbite and rozenite are attributed also to the dry arid/semi-arid areas, in addition to the above mentioned ones. The more stable sulfates, alunogen, halotrichite, szomolnokite, ferricopiapite and gunningite, can form and persists in all climate regimes, from dry continental to even tropical humid. - Highlights: • Efflorescent salts from mining areas have a great impact on the environment. • Secondary minerals are influenced by geology, hydrology, biology and climate. • AMD-precipitates samples were analyzed by XRD, SEM, Raman and NIR spectrometry. • The dehydration temperatures

Efflorescent sulfates from Baia Sprie mining area (Romania) — Acid mine drainage and climatological approach

Energy Technology Data Exchange (ETDEWEB)

Buzatu, Andrei, E-mail: andrei.buzatu@uaic.ro [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania); Dill, Harald G. [Gottfried Wilhelm Leibniz University, Welfengarten 1 D-30167, Hannover (Germany); Buzgar, Nicolae [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania); Damian, Gheorghe [Technical University Cluj Napoca, North University Center of Baia Mare, 62A Dr. Victor Babeş Street, 430083 Baia Mare (Romania); Maftei, Andreea Elena; Apopei, Andrei Ionuț [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania)

2016-01-15

The Baia Sprie epithermal system, a well-known deposit for its impressive mineralogical associations, shows the proper conditions for acid mine drainage and can be considered a general example for affected mining areas around the globe. Efflorescent samples from the abandoned open pit Minei Hill have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and near-infrared (NIR) spectrometry. The identified phases represent mostly iron sulfates with different hydration degrees (szomolnokite, rozenite, melanterite, coquimbite, ferricopiapite), Zn and Al sulfates (gunningite, alunogen, halotrichite). The samples were heated at different temperatures in order to establish the phase transformations among the studied sulfates. The dehydration temperatures and intermediate phases upon decomposition were successfully identified for each of mineral phases. Gunningite was the single sulfate that showed no transformations during the heating experiment. All the other sulfates started to dehydrate within the 30–90 °C temperature range. The acid mine drainage is the main cause for sulfates formation, triggered by pyrite oxidation as the major source for the abundant iron sulfates. Based on the dehydration temperatures, the climatological interpretation indicated that melanterite formation and long-term presence is related to continental and temperate climates. Coquimbite and rozenite are attributed also to the dry arid/semi-arid areas, in addition to the above mentioned ones. The more stable sulfates, alunogen, halotrichite, szomolnokite, ferricopiapite and gunningite, can form and persists in all climate regimes, from dry continental to even tropical humid. - Highlights: • Efflorescent salts from mining areas have a great impact on the environment. • Secondary minerals are influenced by geology, hydrology, biology and climate. • AMD-precipitates samples were analyzed by XRD, SEM, Raman and NIR spectrometry. • The dehydration temperatures

Diode temperature sensor array for measuring and controlling micro scale surface temperature

International Nuclear Information System (INIS)

Han, Il Young; Kim, Sung Jin

2004-01-01

The needs of micro scale thermal detecting technique are increasing in biology and chemical industry. For example, thermal finger print, Micro PCR(Polymer Chain Reaction), TAS and so on. To satisfy these needs, we developed a DTSA(Diode Temperature Sensor Array) for detecting and controlling the temperature on small surface. The DTSA is fabricated by using VLSI technique. It consists of 32 array of diodes(1,024 diodes) for temperature detection and 8 heaters for temperature control on a 8mm surface area. The working principle of temperature detection is that the forward voltage drop across a silicon diode is approximately proportional to the inverse of the absolute temperature of diode. And eight heaters (1K) made of poly-silicon are added onto a silicon wafer and controlled individually to maintain a uniform temperature distribution across the DTSA. Flip chip packaging used for easy connection of the DTSA. The circuitry for scanning and controlling DTSA are also developed

Modelling temporal variance of component temperatures and directional anisotropy over vegetated canopy

Science.gov (United States)

Bian, Zunjian; du, yongming; li, hua

2016-04-01

Land surface temperature (LST) as a key variable plays an important role on hydrological, meteorology and climatological study. Thermal infrared directional anisotropy is one of essential factors to LST retrieval and application on longwave radiance estimation. Many approaches have been proposed to estimate directional brightness temperatures (DBT) over natural and urban surfaces. While less efforts focus on 3-D scene and the surface component temperatures used in DBT models are quiet difficult to acquire. Therefor a combined 3-D model of TRGM (Thermal-region Radiosity-Graphics combined Model) and energy balance method is proposed in the paper for the attempt of synchronously simulation of component temperatures and DBT in the row planted canopy. The surface thermodynamic equilibrium can be final determined by the iteration strategy of TRGM and energy balance method. The combined model was validated by the top-of-canopy DBTs using airborne observations. The results indicated that the proposed model performs well on the simulation of directional anisotropy, especially the hotspot effect. Though we find that the model overestimate the DBT with Bias of 1.2K, it can be an option as a data reference to study temporal variance of component temperatures and DBTs when field measurement is inaccessible

Temperature distribution and heat radiation of patterned surfaces at short wavelengths

Science.gov (United States)

Emig, Thorsten

2017-05-01

We analyze the equilibrium spatial distribution of surface temperatures of patterned surfaces. The surface is exposed to a constant external heat flux and has a fixed internal temperature that is coupled to the outside heat fluxes by finite heat conductivity across the surface. It is assumed that the temperatures are sufficiently high so that the thermal wavelength (a few microns at room temperature) is short compared to all geometric length scales of the surface patterns. Hence the radiosity method can be employed. A recursive multiple scattering method is developed that enables rapid convergence to equilibrium temperatures. While the temperature distributions show distinct dependence on the detailed surface shapes (cuboids and cylinder are studied), we demonstrate robust universal relations between the mean and the standard deviation of the temperature distributions and quantities that characterize overall geometric features of the surface shape.

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.

Surface temperature retrieval in a temperate grassland with multiresolution sensors

Science.gov (United States)

Goetz, S. J.; Halthore, R. N.; Hall, F. G.; Markham, B. L.

1995-12-01

Radiometric surface temperatures retrieved at various spatial resolutions from aircraft and satellite measurements at the FIFE site in eastern Kansas were compared with near-surface temperature measurements to determine the accuracy of the retrieval techniques and consistency between the various sensors. Atmospheric characterizations based on local radiosonde profiles of temperature, pressure, and water vapor were used with the LOWTRAN-7 and MODTRAN atmospheric radiance models to correct measured thermal radiances of water and grassland targets for atmospheric attenuation. Comparison of retrieved surface temperatures from a helicopter-mounted modular multispectral radiometer (MMR) (˜5-m "pixel"), C-130 mounted thematic mapper simulator (TMS) (NS001, ˜20-m pixel), and the Landsat 5 thematic mapper (TM) (120-m pixel) was done. Differences between atmospherically corrected radiative temperatures and near-surface measurements ranged from less than 1°C to more than 8°C. Corrected temperatures from helicopter-MMR and NS001-TMS were in general agreement with near-surface infrared radiative thermometer (IRT) measurements collected from automated meteorological stations, with mean differences of 3.2°C and 1.7°C for grassland targets. Much better agreement (within 1°C) was found between the retrieved aircraft surface temperatures and near-surface measurements acquired with a hand-held mast equipped with a MMR and IRT. The NS001-TMS was also in good agreement with near-surface temperatures acquired over water targets. In contrast, the Landsat 5 TM systematically overestimated surface temperature in all cases. This result has been noted previously but not consistently. On the basis of the results reported here, surface measurements were used to provide a calibration of the TM thermal channel. Further evaluation of the in-flight radiometric calibration of the TM thermal channel is recommended.

ISLSCP II Sea Surface Temperature

Data.gov (United States)

National Aeronautics and Space Administration — Sea surface temperature (SST) is an important indicator of the state of the earth climate system as well as a key variable in the coupling between the atmosphere and...

Merged Land and Ocean Surface Temperature, Version 3.5

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The historical Merged Land-Ocean Surface Temperature Analysis (MLOST) is derived from two independent analyses, an Extended Reconstructed Sea Surface Temperature...

NOAA Extended Reconstructed Sea Surface Temperature (ERSST), Version 5

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature dataset derived from the International...

AFSC/ABL: Auke Bay Climatology 1959-2013

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Data set includes available climatological and related physical environmental records for Auke Bay, Auke Creek and Auke Lake beginning in 1959. Daily high and low...

PERSPECTIVE Working towards a community-wide understanding of satellite skin temperature observations

Science.gov (United States)

Shreve, Cheney

2010-12-01

With more than sixty free and publicly available high-quality datasets, including ecosystem variables, radiation budget variables, and land cover products, the MODIS instrument and the MODIS scientific team have contributed significantly to scientific investigations of ecosystems across the globe. The MODIS instrument, launched in December 1999, has 36 spectral bands, a viewing swath of 2330 km, and acquires data at 250 m, 500 m, and 1000 m spatial resolution every one to two days. Radiation budget variables include surface reflectance, skin temperature, emissivity, and albedo, to list a few. Ecosystem variables include several vegetation indices and productivity measures. Land cover characteristics encompass land cover classifications as well as model parameters and vegetation classifications. Many of these products are instrumental in constraining global climate models and climate change studies, as well as monitoring events such as the recent flooding in Pakistan, the unprecedented oil spill in the Gulf of Mexico, or phytoplankton bloom in the Barents Sea. While product validation efforts by the MODIS scientific team are both vigorous and continually improving, validation is unquestionably one of the most difficult tasks when dealing with remotely derived datasets, especially at the global scale. The quality and availability of MODIS data have led to widespread usage in the scientific community that has further contributed to validation and development of the MODIS products. In their recent paper entitled 'Land surface skin temperature climatology: benefitting from the strengths of satellite observations', Jin and Dickinson review the scientific theory behind, and demonstrate application of, a MODIS temperature product: surface skin temperature. Utilizing datasets from the Global Historical Climatological Network (GHCN), daily skin and air temperature from the Atmospheric Radiation Measurement (ARM) program, and MODIS products (skin temperature, albedo, land

Temperature-mediated transition from Dyakonov-Tamm surface waves to surface-plasmon-polariton waves

Science.gov (United States)

Chiadini, Francesco; Fiumara, Vincenzo; Mackay, Tom G.; Scaglione, Antonio; Lakhtakia, Akhlesh

2017-08-01

The effect of changing the temperature on the propagation of electromagnetic surface waves (ESWs), guided by the planar interface of a homogeneous isotropic temperature-sensitive material (namely, InSb) and a temperature-insensitive structurally chiral material (SCM) was numerically investigated in the terahertz frequency regime. As the temperature rises, InSb transforms from a dissipative dielectric material to a dissipative plasmonic material. Correspondingly, the ESWs transmute from Dyakonov-Tamm surface waves into surface-plasmon-polariton waves. The effects of the temperature change are clearly observed in the phase speeds, propagation distances, angular existence domains, multiplicity, and spatial profiles of energy flow of the ESWs. Remarkably large propagation distances can be achieved; in such instances the energy of an ESW is confined almost entirely within the SCM. For certain propagation directions, simultaneous excitation of two ESWs with (i) the same phase speeds but different propagation distances or (ii) the same propagation distances but different phase speeds are also indicated by our results.

Recent Development on the NOAA's Global Surface Temperature Dataset

Science.gov (United States)

Zhang, H. M.; Huang, B.; Boyer, T.; Lawrimore, J. H.; Menne, M. J.; Rennie, J.

2016-12-01

Global Surface Temperature (GST) is one of the most widely used indicators for climate trend and extreme analyses. A widely used GST dataset is the NOAA merged land-ocean surface temperature dataset known as NOAAGlobalTemp (formerly MLOST). The NOAAGlobalTemp had recently been updated from version 3.5.4 to version 4. The update includes a significant improvement in the ocean surface component (Extended Reconstructed Sea Surface Temperature or ERSST, from version 3b to version 4) which resulted in an increased temperature trends in recent decades. Since then, advancements in both the ocean component (ERSST) and land component (GHCN-Monthly) have been made, including the inclusion of Argo float SSTs and expanded EOT modes in ERSST, and the use of ISTI databank in GHCN-Monthly. In this presentation, we describe the impact of those improvements on the merged global temperature dataset, in terms of global trends and other aspects.

Uncertainties in Climatological Seawater Density Calculations

Science.gov (United States)

Dai, Hao; Zhang, Xining

2018-03-01

In most applications, with seawater conductivity, temperature, and pressure data measured in situ by various observation instruments e.g., Conductivity-Temperature-Depth instruments (CTD), the density which has strong ties to ocean dynamics and so on is computed according to equations of state for seawater. This paper, based on density computational formulae in the Thermodynamic Equation of Seawater 2010 (TEOS-10), follows the Guide of the expression of Uncertainty in Measurement (GUM) and assesses the main sources of uncertainties. By virtue of climatological decades-average temperature/Practical Salinity/pressure data sets in the global ocean provided by the National Oceanic and Atmospheric Administration (NOAA), correlation coefficients between uncertainty sources are determined and the combined standard uncertainties uc>(ρ>) in seawater density calculations are evaluated. For grid points in the world ocean with 0.25° resolution, the standard deviations of uc>(ρ>) in vertical profiles cover the magnitude order of 10-4 kg m-3. The uc>(ρ>) means in vertical profiles of the Baltic Sea are about 0.028kg m-3 due to the larger scatter of Absolute Salinity anomaly. The distribution of the uc>(ρ>) means in vertical profiles of the world ocean except for the Baltic Sea, which covers the range of >(0.004,0.01>) kg m-3, is related to the correlation coefficient r>(SA,p>) between Absolute Salinity SA and pressure p. The results in the paper are based on sensors' measuring uncertainties of high accuracy CTD. Larger uncertainties in density calculations may arise if connected with lower sensors' specifications. This work may provide valuable uncertainty information required for reliability considerations of ocean circulation and global climate models.

Observational and Dynamical Wave Climatologies. VOS vs Satellite Data

Science.gov (United States)

Grigorieva, Victoria; Badulin, Sergei; Chernyshova, Anna

2013-04-01

The understanding physics of wind-driven waves is crucially important for fundamental science and practical applications. This is why experimental efforts are targeted at both getting reliable information on sea state and elaborating effective tools of the sea wave forecasting. The global Visual Wave Observations and satellite data from the GLOBWAVE project of the European Space Agency are analyzed in the context of these two viewpoints. Within the first "observational" aspect we re-analyze conventional climatologies of all basic wave parameters for the last decades [5]. An alternative "dynamical" climatology is introduced as a tool of prediction of dynamical features of sea waves on global scales. The features of wave dynamics are studied in terms of one-parametric dependencies of wave heights on wave periods following the theoretical concept of self-similar wind-driven seas [3, 1, 4] and recently proposed approach to analysis of Voluntary Observing Ship (VOS) data [2]. Traditional "observational" climatologies based on VOS and satellite data collections demonstrate extremely consistent pictures for significant wave heights and dominant periods. On the other hand, collocated satellite and VOS data show significant differences in wave heights, wind speeds and, especially, in wave periods. Uncertainties of visual wave observations can explain these differences only partially. We see the key reason of this inconsistency in the methods of satellite data processing which are based on formal application of data interpolation methods rather than on up-to-date physics of wind-driven waves. The problem is considered within the alternative climatology approach where dynamical criteria of wave height-to-period linkage are used for retrieving wave periods and constructing physically consistent dynamical climatology. The key dynamical parameter - exponent R of one-parametric dependence Hs ~ TR shows dramatically less pronounced latitudinal dependence as compared to observed Hs

User-Defined Meteorological (MET) Profiles from Climatological and Extreme Condition Data

Science.gov (United States)

2018-04-01

ARL-TN-0876 ● MAR 2018 US Army Research Laboratory User-Defined Meteorological (MET) Profiles from Climatological and Extreme...needed. Do not return it to the originator. ARL-TN-0876 ● MAR 2018 US Army Research Laboratory User-Defined Meteorological (MET...User-Defined Meteorological (MET) Profiles from Climatological and Extreme Condition Data 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

The effects of sea surface temperature gradients on surface turbulent fluxes

Science.gov (United States)

Steffen, John

A positive correlation between sea surface temperature (SST) and wind stress perturbation near strong SST gradients (DeltaSST) has been observed in different parts of the world ocean, such as the Gulf Stream in the North Atlantic and the Kuroshio Extension east of Japan. These changes in winds and SSTs can modify near-surface stability, surface stress, and latent and sensible heat fluxes. In general, these small scale processes are poorly modeled in Numerical Weather Prediction (NWP) and climate models. Failure to account for these air--sea interactions produces inaccurate values of turbulent fluxes, and therefore a misrepresentation of the energy, moisture, and momentum budgets. Our goal is to determine the change in these surface turbulent fluxes due to overlooking the correlated variability in winds, SSTs, and related variables. To model these air--sea interactions, a flux model was forced with and without SST--induced changes to the surface wind fields. The SST modification to the wind fields is based on a baroclinic argument as implemented by the University of Washington Planetary Boundary-Layer (UWPBL) model. Other input parameters include 2-m air temperature, 2-m dew point temperature, surface pressure (all from ERA--interim), and Reynolds Daily Optimum Interpolation Sea Surface Temperature (OISST). Flux model runs are performed every 6 hours starting in December 2002 and ending in November 2003. From these model outputs, seasonal, monthly, and daily means of the difference between DeltaSST and no DeltaSST effects on sensible heat flux (SHF), latent heat flux (LHF), and surface stress are calculated. Since the greatest impacts occur during the winter season, six additional December-January-February (DJF) seasons were analyzed for 1987--1990 and 1999--2002. The greatest differences in surface turbulent fluxes are concentrated near strong SST fronts associated with the Gulf Stream and Kuroshio Extension. On average, 2002---2003 DJF seasonal differences in SHF

Surface temperature and surface heat flux determination of the inverse heat conduction problem for a slab

International Nuclear Information System (INIS)

Kuroyanagi, Toshiyuki

1983-07-01

Based on an idea that surface conditions should be a reflection of interior temperature and interior heat flux variation as inverse as interior conditions has been determined completely by the surface temperature and/on surface heat flux as boundary conditions, a method is presented for determining the surface temperature and the surface heat flux of a solid when the temperature and heat flux at an interior point are a prescribed function of time. The method is developed by the integration of Duhumels' integral which has unknown temperature or unknown heat flux in its integrand. Specific forms of surface condition determination are developed for a sample inverse problem: slab. Ducussing the effect of a degree of avairable informations at an interior point due to damped system and the effect of variation of surface conditions on those formulations, it is shown that those formulations are capable of representing the unknown surface conditions except for small time interval followed by discontinuous change of surface conditions. The small un-resolved time interval is demonstrated by a numerical example. An evaluation method of heat flux at an interior point, which is requested by those formulations, is discussed. (author)

Fiber-Optic Surface Temperature Sensor Based on Modal Interference

Directory of Open Access Journals (Sweden)

Frédéric Musin

2016-07-01

Full Text Available Spatially-integrated surface temperature sensing is highly useful when it comes to controlling processes, detecting hazardous conditions or monitoring the health and safety of equipment and people. Fiber-optic sensing based on modal interference has shown great sensitivity to temperature variation, by means of cost-effective image-processing of few-mode interference patterns. New developments in the field of sensor configuration, as described in this paper, include an innovative cooling and heating phase discrimination functionality and more precise measurements, based entirely on the image processing of interference patterns. The proposed technique was applied to the measurement of the integrated surface temperature of a hollow cylinder and compared with a conventional measurement system, consisting of an infrared camera and precision temperature probe. As a result, the optical technique is in line with the reference system. Compared with conventional surface temperature probes, the optical technique has the following advantages: low heat capacity temperature measurement errors, easier spatial deployment, and replacement of multiple angle infrared camera shooting and the continuous monitoring of surfaces that are not visually accessible.

Surface alloying in Sn/Au(111) at elevated temperature

Science.gov (United States)

Sadhukhan, Pampa; Singh, Vipin Kumar; Rai, Abhishek; Bhattacharya, Kuntala; Barman, Sudipta Roy

2018-04-01

On the basis of x-ray photoelectron spectroscopy, we show that when Sn is deposited on Au(111) single crystal surface at a substrate temperature TS=373 K, surface alloying occurs with the formation of AuSn phase. The evolution of the surface structure and the surface morphology has been studied by low energy electron diffraction and scanning tunneling microscopy, respectively as a function of Sn coverage and substrate temperatures.

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.

Spatio-temporal precipitation climatology over complex terrain using a censored additive regression model.

Science.gov (United States)

Stauffer, Reto; Mayr, Georg J; Messner, Jakob W; Umlauf, Nikolaus; Zeileis, Achim

2017-06-15

Flexible spatio-temporal models are widely used to create reliable and accurate estimates for precipitation climatologies. Most models are based on square root transformed monthly or annual means, where a normal distribution seems to be appropriate. This assumption becomes invalid on a daily time scale as the observations involve large fractions of zero observations and are limited to non-negative values. We develop a novel spatio-temporal model to estimate the full climatological distribution of precipitation on a daily time scale over complex terrain using a left-censored normal distribution. The results demonstrate that the new method is able to account for the non-normal distribution and the large fraction of zero observations. The new climatology provides the full climatological distribution on a very high spatial and temporal resolution, and is competitive with, or even outperforms existing methods, even for arbitrary locations.

SiGe Based Low Temperature Electronics for Lunar Surface Applications

Science.gov (United States)

Mojarradi, Mohammad M.; Kolawa, Elizabeth; Blalock, Benjamin; Cressler, John

2012-01-01

The temperature at the permanently shadowed regions of the moon's surface is approximately -240 C. Other areas of the lunar surface experience temperatures that vary between 120 C and -180 C during the day and night respectively. To protect against the large temperature variations of the moon surface, traditional electronics used in lunar robotics systems are placed inside a thermally controlled housing which is bulky, consumes power and adds complexity to the integration and test. SiGe Based electronics have the capability to operate over wide temperature range like that of the lunar surface. Deploying low temperature SiGe electronics in a lander platform can minimize the need for the central thermal protection system and enable the development of a new generation of landers and mobility platforms with highly efficient distributed architecture. For the past five years a team consisting of NASA, university and industry researchers has been examining the low temperature and wide temperature characteristic of SiGe based transistors for developing electronics for wide temperature needs of NASA environments such as the Moon, Titan, Mars and Europa. This presentation reports on the status of the development of wide temperature SiGe based electronics for the landers and lunar surface mobility systems.

Surface layer temperature inversion in the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Pankajakshan, T.; Gopalakrishna, V.V.; Muraleedharan, P.M.; Reddy, G.V.; Araligidad, N.; Shenoy, Shrikant

Surface layer temperature inversion occurring in the Bay of Bengal has been addressed. Hydrographic data archived in the Indian Oceanographic Data Center are used to understand various aspects of the temperature inversion of surface layer in the Bay...

Temperature effect on surface oxidation of titanium

International Nuclear Information System (INIS)

Vaquilla, I.; Barco, J.L. del; Ferron, J.

1990-01-01

The effect of temperature on the first stages of the superficial oxidation of polycrystalline titanium was studied using both Auger electron spectroscopy (AES) and emission shreshold (AEAPS). The number of compounds present on the surface was determined by application of the factor analysis technique. Reaction evolution was followed through the relative variation of Auger LMM and LMV transitions which are characteristic of titanium. Also the evolution of the chemical shift was determined by AEAPS. The amount of oxygen on the surface was quantified using transition KLL of oxygen. It was found that superficial oxidation depends on temperature. As much as three different compounds were determined according to substrate temperature and our exposure ranges. (Author). 7 refs., 5 figs

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

International Nuclear Information System (INIS)

Dominguez Ley, Orlando; Caveda Ramos, Celia; Ramos Viltre, Emma O.; Dominguez Garcia, Adriel; Alonso Abad, Dolores

2008-01-01

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)

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...

World Ocean Atlas 2005, Temperature

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — World Ocean Atlas 2005 (WOA05) is a set of objectively analyzed (1° grid) climatological fields of in situ temperature, salinity, dissolved oxygen, Apparent Oxygen...

Identifying anthropogenic anomalies in air, surface and groundwater temperatures in Germany.

Science.gov (United States)

Benz, Susanne A; Bayer, Peter; Blum, Philipp

2017-04-15

Human activity directly influences ambient air, surface and groundwater temperatures. The most prominent phenomenon is the urban heat island effect, which has been investigated particularly in large and densely populated cities. This study explores the anthropogenic impact on the thermal regime not only in selected urban areas, but on a countrywide scale for mean annual temperature datasets in Germany in three different compartments: measured surface air temperature, measured groundwater temperature, and satellite-derived land surface temperature. Taking nighttime lights as an indicator of rural areas, the anthropogenic heat intensity is introduced. It is applicable to each data set and provides the difference between measured local temperature and median rural background temperature. This concept is analogous to the well-established urban heat island intensity, but applicable to each measurement point or pixel of a large, even global, study area. For all three analyzed temperature datasets, anthropogenic heat intensity grows with increasing nighttime lights and declines with increasing vegetation, whereas population density has only minor effects. While surface anthropogenic heat intensity cannot be linked to specific land cover types in the studied resolution (1km×1km) and classification system, both air and groundwater show increased heat intensities for artificial surfaces. Overall, groundwater temperature appears most vulnerable to human activity, albeit the different compartments are partially influenced through unrelated processes; unlike land surface temperature and surface air temperature, groundwater temperatures are elevated in cultivated areas as well. At the surface of Germany, the highest anthropogenic heat intensity with 4.5K is found at an open-pit lignite mine near Jülich, followed by three large cities (Munich, Düsseldorf and Nuremberg) with annual mean anthropogenic heat intensities >4K. Overall, surface anthropogenic heat intensities >0K and

Contributions of changes in climatology and perturbation and the resulting nonlinearity to regional climate change.

Science.gov (United States)

Adachi, Sachiho A; Nishizawa, Seiya; Yoshida, Ryuji; Yamaura, Tsuyoshi; Ando, Kazuto; Yashiro, Hisashi; Kajikawa, Yoshiyuki; Tomita, Hirofumi

2017-12-20

Future changes in large-scale climatology and perturbation may have different impacts on regional climate change. It is important to understand the impacts of climatology and perturbation in terms of both thermodynamic and dynamic changes. Although many studies have investigated the influence of climatology changes on regional climate, the significance of perturbation changes is still debated. The nonlinear effect of these two changes is also unknown. We propose a systematic procedure that extracts the influences of three factors: changes in climatology, changes in perturbation and the resulting nonlinear effect. We then demonstrate the usefulness of the procedure, applying it to future changes in precipitation. All three factors have the same degree of influence, especially for extreme rainfall events. Thus, regional climate assessments should consider not only the climatology change but also the perturbation change and their nonlinearity. This procedure can advance interpretations of future regional climates.

The impact of inter-annual variability of annual cycle on long-term persistence of surface air temperature in long historical records

Science.gov (United States)

Deng, Qimin; Nian, Da; Fu, Zuntao

2018-02-01

Previous studies in the literature show that the annual cycle of surface air temperature (SAT) is changing in both amplitude and phase, and the SAT departures from the annual cycle are long-term correlated. However, the classical definition of temperature anomalies is based on the assumption that the annual cycle is constant, which contradicts the fact of changing annual cycle. How to quantify the impact of the changing annual cycle on the long-term correlation of temperature anomaly variability still remains open. In this paper, a recently developed data adaptive analysis tool, the nonlinear mode decomposition (NMD), is used to extract and remove time-varying annual cycle to reach the new defined temperature anomalies in which time-dependent amplitude of annual cycle has been considered. By means of detrended fluctuation analysis, the impact induced by inter-annual variability from the time-dependent amplitude of annual cycle has been quantified on the estimation of long-term correlation of long historical temperature anomalies in Europe. The results show that the classical climatology annual cycle is supposed to lack inter-annual fluctuation which will lead to a maximum artificial deviation centering around 600 days. This maximum artificial deviation is crucial to defining the scaling range and estimating the long-term persistence exponent accurately. Selecting different scaling range could lead to an overestimation or underestimation of the long-term persistence exponent. By using NMD method to extract the inter-annual fluctuations of annual cycle, this artificial crossover can be weakened to extend a wider scaling range with fewer uncertainties.

A new atlas of temperature and salinity for the North Indian Ocean

Indian Academy of Sciences (India)

The most used temperature and salinity climatology for the world ocean, including the Indian Ocean, is the World Ocean Atlas (WOA) (Antonov et al 2006, 2010; Locarnini et al 2006, 2010) because of the vast amount of data used in its preparation. The WOA climatology does not, however, include all the available ...

Global Historical Climatology Network - Monthly Temperature, Version 4 (BETA)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Only available as BETA release. The GHCN-Monthly Temperature Version 4 dataset consists of monthly mean temperature - both raw and bias corrected data. A full...

Temporal Arctic longwave surface emissivity feedbacks in the Community Earth System Model

Science.gov (United States)

Kuo, C.; Feldman, D.; Huang, X.; Flanner, M.; Yang, P.; Chen, X.

2017-12-01

We have investigated how the inclusion of realistic and consistent surface emissivity in both land-surface and atmospheric components of the CESM coupled-climate model affects a wide range of climate variables. We did this by replacing the unit emissivity values in RRTMG_LW for water, fine-grained snow, and desert scenes with spectral emissivity values, and by replacing broadband emissivity values in surface components with the Planck-curve weighted counterparts. We find that this harmonized treatment of surface emissivity within CESM can be important for reducing high-latitude temperature biases. We also find that short-term effects of atmospheric dynamics and spectral information need to be considered to understand radiative effects in higher detail, and are possible with radiative kernels computed for every grid and time point for the entire model integration period. We find that conventional climatological feedback calculations indicate that sea-ice emissivity feedback is positive in sign, but that the radiative effects of the difference in emissivity between frozen and unfrozen surfaces exhibit seasonal dependence. Furthermore, this seasonality itself exhibits meridional asymmetry due to differences in sea-ice response to climate forcing between the Arctic and the Antarctic. In the Arctic, this seasonal, temporally higher order analysis exhibits increasing outgoing surface emissivity radiative response in a warming climate. While the sea-ice emissivity feedback and seasonal sea-ice emissivity radiative response amplitudes are a few percent of surface albedo feedbacks, the feedback analysis methods outlined in this work demonstrate that spatially and temporally localized feedback analysis can give insight into the mechanisms at work on those scales which differ in amplitude and sign from conventional climatological analyses. We note that the inclusion of this realistic physics leads to improved agreement between CESM model results and Arctic surface

An experimental method for making spectral emittance and surface temperature measurements of opaque surfaces

International Nuclear Information System (INIS)

Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Daniel Maynes, R.; Baxter, Larry L.

2011-01-01

An experimental procedure has been developed to make spectral emittance and temperature measurements. The spectral emittance of an object is calculated using measurements of the spectral emissive power and of the surface temperature of the object obtained using a Fourier transform infrared (FTIR) spectrometer. A calibration procedure is described in detail which accounts for the temperature dependence of the detector. The methods used to extract the spectral emissive power and surface temperature from measured infrared spectra were validated using a blackbody radiator at known temperatures. The average error in the measured spectral emittance was 2.1% and the average difference between the temperature inferred from the recorded spectra and the temperature indicated on the blackbody radiator was 1.2%. The method was used to measure the spectral emittance of oxidized copper at various temperatures.

Molecular dynamics simulation of temperature effects on low energy near-surface cascades and surface damage in Cu

Science.gov (United States)

Zhu, Guo; Sun, Jiangping; Guo, Xiongxiong; Zou, Xixi; Zhang, Libin; Gan, Zhiyin

2017-06-01

The temperature effects on near-surface cascades and surface damage in Cu(0 0 1) surface under 500 eV argon ion bombardment were studied using molecular dynamics (MD) method. In present MD model, substrate system was fully relaxed for 1 ns and a read-restart scheme was introduced to save total computation time. The temperature dependence of damage production was calculated. The evolution of near-surface cascades and spatial distribution of adatoms at varying temperature were analyzed and compared. It was found that near-surface vacancies increased with temperature, which was mainly due to the fact that more atoms initially located in top two layers became adatoms with the decrease of surface binding energy. Moreover, with the increase of temperature, displacement cascades altered from channeling-like structure to branching structure, and the length of collision sequence decreased gradually, because a larger portion of energy of primary knock-on atom (PKA) was scattered out of focused chain. Furthermore, increasing temperature reduced the anisotropy of distribution of adatoms, which can be ascribed to that regular registry of surface lattice atoms was changed with the increase of thermal vibration amplitude of surface atoms.

Molecular dynamics simulation of temperature effects on low energy near-surface cascades and surface damage in Cu

Energy Technology Data Exchange (ETDEWEB)

Zhu, Guo; Sun, Jiangping; Guo, Xiongxiong; Zou, Xixi; Zhang, Libin; Gan, Zhiyin, E-mail: ganzhiyin@126.com

2017-06-15

The temperature effects on near-surface cascades and surface damage in Cu(0 0 1) surface under 500 eV argon ion bombardment were studied using molecular dynamics (MD) method. In present MD model, substrate system was fully relaxed for 1 ns and a read-restart scheme was introduced to save total computation time. The temperature dependence of damage production was calculated. The evolution of near-surface cascades and spatial distribution of adatoms at varying temperature were analyzed and compared. It was found that near-surface vacancies increased with temperature, which was mainly due to the fact that more atoms initially located in top two layers became adatoms with the decrease of surface binding energy. Moreover, with the increase of temperature, displacement cascades altered from channeling-like structure to branching structure, and the length of collision sequence decreased gradually, because a larger portion of energy of primary knock-on atom (PKA) was scattered out of focused chain. Furthermore, increasing temperature reduced the anisotropy of distribution of adatoms, which can be ascribed to that regular registry of surface lattice atoms was changed with the increase of thermal vibration amplitude of surface atoms.

Safety assessment of greenhouse hydroponic tomatoes irrigated with reclaimed and surface water.

Science.gov (United States)

Lopez-Galvez, Francisco; Allende, Ana; Pedrero-Salcedo, Francisco; Alarcon, Juan Jose; Gil, Maria Isabel

2014-11-17

The impact of reclaimed and surface water on the microbiological safety of hydroponic tomatoes was assessed. Greenhouse tomatoes were irrigated with reclaimed and surface water and grown on two hydroponic substrates (coconut fiber and rock wool). Water samples (n=208) were taken from irrigation water, with and without the addition of fertilizers and drainage water, and hydroponic tomatoes (n=72). Samples were analyzed for indicator microorganisms, generic Escherichia coli and Listeria spp., and pathogenic bacteria such as Salmonella spp. and Shiga-toxigenic E. coli (STEC), using multiplex real-time PCR (RT-PCR) after enrichment. The correlation between climatological parameters such as temperature and the levels of microorganisms in water samples was also determined. In irrigation water, generic E. coli counts were higher in reclaimed than in surface water whereas Listeria spp. numbers increased after adding the fertilizers in both water sources. In drainage water, no clear differences in E. coli and Listeria numbers were observed between reclaimed and surface water. No positive samples for STEC were found in irrigation water. Presumptive positives for Salmonella spp. were found in 7.7% of the water samples and 62.5% of these samples were reclaimed water. Salmonella-positive samples by RT-PCR could not be confirmed by conventional methods. Higher concentrations of E. coli were associated with Salmonella-presumptive positive samples. Climatological parameters, such as temperature, were not correlated with the E. coli and Listeria spp. counts. Tomato samples were negative for bacterial pathogens, while generic E. coli and Listeria spp. counts were below the detection limit. The prevalence of presumptive Salmonella spp. found in irrigation water (reclaimed and surface water) was high, which might present a risk of contamination. The absence of pathogens on greenhouse hydroponic tomatoes indicates that good agricultural practices (GAP) were in place, avoiding the

A comprehensive overview of the climatological composition of the Asian summer monsoon anticyclone based on 10 years of Aura Microwave Limb Sounder measurements

Science.gov (United States)

Santee, M. L.; Manney, G. L.; Livesey, N. J.; Schwartz, M. J.; Neu, J. L.; Read, W. G.

2017-05-01

Intense deep convection associated with the Asian summer monsoon (ASM) lofts surface pollutants to the upper troposphere/lower stratosphere (UTLS), where strong winds and long chemical lifetimes allow intercontinental transport, affecting atmospheric composition around the globe. The Aura Microwave Limb Sounder (MLS), launched in 2004, makes simultaneous colocated measurements of trace gases and cloud ice water content (a proxy for deep convection) in the UTLS on a daily basis. Here we exploit the dense spatial and temporal coverage, long-term data record, extensive measurement suite, and insensitivity to aerosol and most clouds of Aura MLS to characterize the climatological (2005-2014) composition of the ASM anticyclone throughout its annual life cycle. We use version 4 MLS data to quantify spatial and temporal variations in both tropospheric (H2O, CO, CH3Cl, CH3CN, CH3OH) and stratospheric (O3, HNO3, HCl) tracers on four potential temperature surfaces (350-410 K). Inside the mature anticyclone, all species exhibit substantial changes, not only from their premonsoon distributions in the ASM region but also from their summertime distributions in the rest of the hemisphere. Different tracers exhibit dissimilar seasonal evolution, and the exact location and timing of their extreme values vary. Although individual aspects of the anticyclone have been described previously, we present a uniquely comprehensive overview of the climatological seasonal evolution of the ASM and its impact on UTLS composition. This work provides valuable context for planned in situ measurements as well as a benchmark for model evaluation and future investigations of interannual variability and long-term changes in monsoon processes.

The approximate determination of the critical temperature of a liquid by measuring surface tension versus the temperature

International Nuclear Information System (INIS)

Maroto, J A; Nieves, F J de las; Quesada-Perez, M

2004-01-01

A classical experience in a physics student laboratory is to determine the surface tension of a liquid versus the temperature and to check the linear appearance of the obtained graph. In this work we show a simple method to estimate the critical temperature of three liquids by using experimental data of surface tension at different temperatures. By a logarithm fitting between surface tension and temperature, the critical temperature can be determined and compared with data from the literature. For two liquids (butanol and nitrobenzene) the comparison is acceptable but the differences are too high for the third liquid (water). By discussing the results it seems to be clear that the difference between the critical temperature of the liquid and the maximum temperature of the surface tension measurements is the determining factor in obtaining acceptable results. From this study it is possible to obtain more information on the liquid characteristics from surface tension measurements that are currently carried out in a student laboratory. Besides, in this paper it is shown how to select the most suitable liquids which provide both acceptable values for the critical temperature and measurements of the surface tension at moderate temperatures. The complementary use of numerical methods permits us to offer a complete experience for the students with a simple laboratory experiment which we recommend for physics students in advanced university courses

The influence of the Amundsen Sea Low on the winds in the Ross Sea and surroundings: Insights from a synoptic climatology

Science.gov (United States)

Coggins, Jack H. J.; McDonald, Adrian J.

2015-03-01

The Amundsen Sea Low (ASL) is an area of climatologically low atmospheric pressure situated over the Southern Ocean. The depth and location of this feature have significant effects on winds, temperature, moisture transport, and sea ice in its vicinity. In this article, we quantify the modulating effect of this feature on winds over the Ross Sea and Ross Ice Shelf. We examine composites of surface winds sampled according to extrema in ASL depth, longitude, and latitude. We employ the output of a previously developed synoptic climatology to identify the explanatory synoptic-scale forcings. In autumn, winter, and spring (AWS) we find that the impact of the depth of the ASL is smaller than that of its location. The ASL moves eastward when it is deep, thereby reducing its influence on Ross Sea winds. When the ASL is northward, we find strongly enhanced southerly flows over the Ross Sea and Ice Shelf, forced by greater cyclonic activity in the north of the Ross Sea. In summer, we find increased cyclonic flow coinciding with a deeper ASL, despite the ASL being located in the Bellingshausen Sea at this time. The responses to the ASL longitude and latitude are profoundly different to those in AWS, suggesting that relationships are strongly dependent on the varying seasonal location of the low. We examine two metrics of the ASL depth and identify that the absolute mean sea level pressure (MSLP) has a more widespread response than that of the relative MSLP.

Remote sensing of land surface temperature: The directional viewing effect

International Nuclear Information System (INIS)

Smith, J.A.; Schmugge, T.J.; Ballard, J.R. Jr.

1997-01-01

Land Surface Temperature (LST) is an important parameter in understanding global environmental change because it controls many of the underlying processes in the energy budget at the surface and heat and water transport between the surface and the atmosphere. The measurement of LST at a variety of spatial and temporal scales and extension to global coverage requires remote sensing means to achieve these goals. Land surface temperature and emissivity products are currently being derived from satellite and aircraft remote sensing data using a variety of techniques to correct for atmospheric effects. Implicit in the commonly employed approaches is the assumption of isotropy in directional thermal infrared exitance. The theoretical analyses indicate angular variations in apparent infrared temperature will typically yield land surface temperature errors ranging from 1 to 4 C unless corrective measures are applied

Temperature profiles on the gadolinium surface during electron beam evaporation

Energy Technology Data Exchange (ETDEWEB)

Ohba, Hironori; Shibata, Takemasa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1995-03-01

The distributions of surface temperature of gadolinium in a water-cooled copper crucible during electron beam evaporation were measured by optical pyrometry. The surface temperatures were obtained from the radiation intensity ratio of the evaporating surface and a reference light source using Planck`s law of radiation. The emitted radiation from the evaporating surface and a reference source was detected by a CCD sensor through a band pass filter of 650 nm. The measured surface temperature generally agreed with those estimated from the deposition rate and the data of the saturated vapor pressure. At high input powers, it was found that the measured value had small difference with the estimated one due to variation of the surface condition. (author).

Temperature profiles on the gadolinium surface during electron beam evaporation

International Nuclear Information System (INIS)

Ohba, Hironori; Shibata, Takemasa

1995-01-01

The distributions of surface temperature of gadolinium in a water-cooled copper crucible during electron beam evaporation were measured by optical pyrometry. The surface temperatures were obtained from the radiation intensity ratio of the evaporating surface and a reference light source using Planck's law of radiation. The emitted radiation from the evaporating surface and a reference source was detected by a CCD sensor through a band pass filter of 650 nm. The measured surface temperature generally agreed with those estimated from the deposition rate and the data of the saturated vapor pressure. At high input powers, it was found that the measured value had small difference with the estimated one due to variation of the surface condition. (author)

TWO METHODS FOR REMOTE ESTIMATION OF COMPLETE URBAN SURFACE TEMPERATURE

Directory of Open Access Journals (Sweden)

L. Jiang

2017-09-01

Full Text Available Complete urban surface temperature (TC is a key parameter for evaluating the energy exchange between the urban surface and atmosphere. At the present stage, the estimation of TC still needs detailed 3D structure information of the urban surface, however, it is often difficult to obtain the geometric structure and composition of the corresponding temperature of urban surface, so that there is still lack of concise and efficient method for estimating the TC by remote sensing. Based on the four typical urban surface scale models, combined with the Envi-met model, thermal radiant directionality forward modeling and kernel model, we analyzed a complete day and night cycle hourly component temperature and radiation temperature in each direction of two seasons of summer and winter, and calculated hemispherical integral temperature and TC. The conclusion is obtained by examining the relationship of directional radiation temperature, hemispherical integral temperature and TC: (1 There is an optimal angle of radiation temperature approaching the TC in a single observation direction when viewing zenith angle is 45–60°, the viewing azimuth near the vertical surface of the sun main plane, the average absolute difference is about 1.1 K in the daytime. (2 There are several (3–5 times directional temperatures of different view angle, under the situation of using the thermal radiation directionality kernel model can more accurately calculate the hemispherical integral temperature close to TC, the mean absolute error is about 1.0 K in the daytime. This study proposed simple and effective strategies for estimating TC by remote sensing, which are expected to improve the quantitative level of remote sensing of urban thermal environment.

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.

2016-01-01

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 O3variability 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) with4530 total profiles. Sensitivity tests on k-means algorithm and SOM justify use of 3 3 SOM (nine clusters). Ateach 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 1316 of profiles, mostly in winter and spring.Large midtropospheric deviations from monthly means (6 ppbv, +710 ppbv O3 at 6 km) are found in two of the most populated clusters (combined 3639 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.

Climatology of the northern hemisphere stratosphere derived from Berlin analyses. Pt. 1. Monthly means

International Nuclear Information System (INIS)

Pawson, S.; Labitzke, K.; Lenschow, R.; Naujokat, B.; Rajewski, B.; Wiesner, M.; Wohlfart, R.C.

1993-01-01

This work presents a climatology of the northern hemisphere lower and middle stratosphere derived from daily radiosonde observations subjectively analysed in the Stratospheric Research Group of the 'Meteorologisches Institut der Freien Universitaet Berlin'. Previous climatologies from these data were presented by Labitzke (1972), van Loon et al. (1972), and by Labitzke and Goretzki (1982). Although some more recent climatological fields have been presented in several works by members of the group, no complete atlas has been compiled for some time. The work is intended to serve as a reference for people interested in the stratosphere and, particularly, the climate analysis and modelling communities, which require contemporary analyses of the available data in order to interpret their products. In this first part of the climatological atlas, monthly mean data are presented. (orig./KW)

Climatology of the northern hemisphere stratosphere derived from Berlin analyses. Pt. 1. Monthly means

Energy Technology Data Exchange (ETDEWEB)

Pawson, S; Labitzke, K; Lenschow, R; Naujokat, B; Rajewski, B; Wiesner, M; Wohlfart, R C

1933-01-01

This work presents a climatology of the northern hemisphere lower and middle stratosphere derived from daily radiosonde observations subjectively analysed in the Stratospheric Research Group of the 'Meteorologisches Institut der Freien Universitaet Berlin'. Previous climatologies from these data were presented by Labitzke (1972), van Loon et al. (1972), and by Labitzke and Goretzki (1982). Although some more recent climatological fields have been presented in several works by members of the group, no complete atlas has been compiled for some time. The work is intended to serve as a reference for people interested in the stratosphere and, particularly, the climate analysis and modelling communities, which require contemporary analyses of the available data in order to interpret their products. In this first part of the climatological atlas, monthly mean data are presented. (orig./KW)

Titan's Surface Temperatures Maps from Cassini - CIRS Observations

Science.gov (United States)

Cottini, Valeria; Nixon, C. A.; Jennings, D. E.; Anderson, C. M.; Samuelson, R. E.; Irwin, P. G. J.; Flasar, F. M.

2009-09-01

The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 μm (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the instrument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature profile by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). In future, application of our methodology over wide areas should greatly increase the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp. 1136-1150, 2008. Rodgers, C. D.: "Inverse Methods For Atmospheric Sounding: Theory and Practice". World Scientific, Singapore, 2000. Jennings, D.E., et al.: "Titan's Surface Brightness Temperatures." Ap. J. L., Vol. 691, pp. L103-L

Inter-Relationship Between Subtropical Pacific Sea Surface Temperature, Arctic Sea Ice Concentration, and the North Atlantic Oscillation in Recent Summers and Winters

Science.gov (United States)

Lim, Young-Kwon; Cullather, Richard I.; Nowicki, Sophie M.; Kim, Kyu-Myong

2017-01-01

The inter-relationship between subtropical western-central Pacific sea surface temperatures (STWCPSST), sea ice concentration in the Beaufort Sea (SICBS), and the North Atlantic Oscillation (NAO) are investigated for the last 37 summers and winters (1980-2016). Lag-correlation of the STWCPSST×(-1) in spring with the NAO phase and SICBS in summer increases over the last two decades, reaching r = 0.4-0.5 with significance at 5 percent, while winter has strong correlations in approximately 1985-2005. Observational analysis and the atmospheric general circulation model experiments both suggest that STWCPSST warming acts to increase the Arctic geopotential height and temperature in the following season. This atmospheric response extends to Greenland, providing favorable conditions for developing the negative phase of the NAO. SIC and surface albedo tend to decrease over the Beaufort Sea in summer, linked to the positive surface net shortwave flux. Energy balance considering radiative and turbulent fluxes reveal that available energy that can heat surface is larger over the Arctic and Greenland and smaller over the south of Greenland, in response to the STWCPSST warming in spring. XXXX Arctic & Atlantic: Positive upper-level height/T anomaly over the Arctic and Greenland, and a negative anomaly over the central-eastern Atlantic, resembling the (-) phase of the NAO. Pacific: The negative height/T anomaly over the mid-latitudes, along with the positive anomaly over the STWCP, where 1degC warming above climatology is prescribed. Discussion: It is likely that the Arctic gets warm and the NAO is in the negative phase in response to the STWCP warming. But, there are other factors (e.g., internal variability) that contribute to determination of the NAO phase: not always the negative phase of the NAO in the event of STWCP warming (e.g.: recent winters and near neutral NAO in 2017 summer).

The NEWS Water Cycle Climatology

Science.gov (United States)

Rodell, M.; Beaudoing, H. K.; L'Ecuyer, T.; Olson, W. S.

2012-12-01

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.

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.

SURFACE TEMPERATURES ON TITAN DURING NORTHERN WINTER AND SPRING

Energy Technology Data Exchange (ETDEWEB)

Jennings, D. E.; Cottini, V.; Nixon, C. A.; Achterberg, R. K.; Flasar, F. M.; Kunde, V. G.; Romani, P. N.; Samuelson, R. E. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mamoutkine, A. [ADNET Systems, Inc., Bethesda, MD 20817 (United States); Gorius, N. J. P. [The Catholic University of America, Washington, DC 20064 (United States); Coustenis, A. [Laboratoire d’Etudes Spatiales et d’Instrumentation en Astrophysique (LESIA), Observatoire de Paris, CNRS, UPMC Univ. Paris 06, Univ. Paris-Diderot, 5, place Jules Janssen, F-92195 Meudon Cedex (France); Tokano, T., E-mail: donald.e.jennings@nasa.gov [Universität zu Köln, Albertus-Magnus-Platz, D-50923 Köln (Germany)

2016-01-01

Meridional brightness temperatures were measured on the surface of Titan during the 2004–2014 portion of the Cassini mission by the Composite Infrared Spectrometer. Temperatures mapped from pole to pole during five two-year periods show a marked seasonal dependence. The surface temperature near the south pole over this time decreased by 2 K from 91.7 ± 0.3 to 89.7 ± 0.5 K while at the north pole the temperature increased by 1 K from 90.7 ± 0.5 to 91.5 ± 0.2 K. The latitude of maximum temperature moved from 19 S to 16 N, tracking the sub-solar latitude. As the latitude changed, the maximum temperature remained constant at 93.65 ± 0.15 K. In 2010 our temperatures repeated the north–south symmetry seen by Voyager one Titan year earlier in 1980. Early in the mission, temperatures at all latitudes had agreed with GCM predictions, but by 2014 temperatures in the north were lower than modeled by 1 K. The temperature rise in the north may be delayed by cooling of sea surfaces and moist ground brought on by seasonal methane precipitation and evaporation.

SURFACE TEMPERATURES ON TITAN DURING NORTHERN WINTER AND SPRING

International Nuclear Information System (INIS)

Jennings, D. E.; Cottini, V.; Nixon, C. A.; Achterberg, R. K.; Flasar, F. M.; Kunde, V. G.; Romani, P. N.; Samuelson, R. E.; Mamoutkine, A.; Gorius, N. J. P.; Coustenis, A.; Tokano, T.

2016-01-01

Meridional brightness temperatures were measured on the surface of Titan during the 2004–2014 portion of the Cassini mission by the Composite Infrared Spectrometer. Temperatures mapped from pole to pole during five two-year periods show a marked seasonal dependence. The surface temperature near the south pole over this time decreased by 2 K from 91.7 ± 0.3 to 89.7 ± 0.5 K while at the north pole the temperature increased by 1 K from 90.7 ± 0.5 to 91.5 ± 0.2 K. The latitude of maximum temperature moved from 19 S to 16 N, tracking the sub-solar latitude. As the latitude changed, the maximum temperature remained constant at 93.65 ± 0.15 K. In 2010 our temperatures repeated the north–south symmetry seen by Voyager one Titan year earlier in 1980. Early in the mission, temperatures at all latitudes had agreed with GCM predictions, but by 2014 temperatures in the north were lower than modeled by 1 K. The temperature rise in the north may be delayed by cooling of sea surfaces and moist ground brought on by seasonal methane precipitation and evaporation

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.

OW NOAA GOES Sea-Surface Temperature

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface temperature measurements collected by means of the Geostationary Orbiting Environmental Satellite. The data is...

Processes of India's offshore summer intraseasonal sea surface temperature variability

Digital Repository Service at National Institute of Oceanography (India)

Kurian, N.; Lengaigne, M.; Gopalakrishna, V.V.; Vialard, J.; Pous, S.; Peter, A-C.; Durand, F.; Naik, Shweta

study, we use an eddy-permitting 0.25 degrees regional ocean model to investigate mechanisms of this offshore intraseasonal SST variability. Modelled climatological mixed layer and upper thermocline depth are in very good agreement with estimates from...

OW AVISO Sea-Surface Height & Niiler Climatology

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface height measurements collected by means of the TOPEX/Poseidon/ERS, JASON-1/Envisat, and Jason-2/Envisat satellite...

Forecasting Temporal and Spatial Climatological Influence for Land Suitability Evaluation in Bentota Sri Lanka

Directory of Open Access Journals (Sweden)

Gayani Ranasinghe

2017-01-01

Full Text Available Climate change has raised much concern regarding its impacts on future land use planning, varying by region, time, and socio-economic development path. The principle purpose of land suitability evaluation is to predict the potential and limitation of the land for crop production and other land uses. This study was carried out to predict the temperature and rainfall trends as one of the major factor for evaluating land suitability. Climatic data such as monthly mean temperature, total monthly rainfall, maximum daily rainfall and total annual rainfall during last 30 years of all weather stations located in Bentota River basin was collected and analyzed applying time series analysis, correlation analysis and Manna Kendall trend test methods. Spatial distribution of forecast rainfall values was illustrated applying Arc GIS software. The findings revealed that monthly mean temperature and maximum daily rainfall had a general increasing trend whereas, total monthly rainfall and total annual rainfall showed a general decreasing trend in  Bentota area. It was indicated relatively high rainfall situations during May and October while low rainfall situations during January and February by occurring flood situation in once per five year. During Yala season the area will be received comparatively more rainfall (331mm than Maha season (300mm in future. Community and the farmers in this area can be aware about the anticipated spatial distribution of total monthly rainfall during two major seasons and flood occurrence periods. Decision makers should evaluate land suitability of Bentota area by considering above climatological influences and its spatial distribution pattern that identified as major outcome of this research. The approach and the methodology adopted in this study will be useful for other researchers, agriculturalist and planners to identify the future climatological influences and its spatial distribution pattern for land suitability evaluations

Situational Lightning Climatologies for Central Florida: Phase IV

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.

Surface temperature measurement of plasma facing components in tokamaks

International Nuclear Information System (INIS)

Amiel, Stephane

2014-01-01

During this PhD, the challenges on the non-intrusive surface temperature measurements of metallic plasma facing components in tokamaks are reported. Indeed, a precise material emissivity value is needed for classical infrared methods and the environment contribution has to be known particularly for low emissivities materials. Although methods have been developed to overcome these issues, they have been implemented solely for dedicated experiments. In any case, none of these methods are suitable for surface temperature measurement in tokamaks.The active pyrometry introduced in this study allows surface temperature measurements independently of reflected flux and emissivities using pulsed and modulated photothermal effect. This method has been validated in laboratory on metallic materials with reflected fluxes for pulsed and modulated modes. This experimental validation is coupled with a surface temperature variation induced by photothermal effect and temporal signal evolvement modelling in order to optimize both the heating source characteristics and the data acquisition and treatment. The experimental results have been used to determine the application range in temperature and detection wavelengths. In this context, the design of an active pyrometry system on tokamak has been completed, based on a bicolor camera for a thermography application in metallic (or low emissivity) environment.The active pyrometry method introduced in this study is a complementary technique of classical infrared methods used for thermography in tokamak environment which allows performing local and 2D surface temperature measurements independently of reflected fluxes and emissivities. (author) [fr

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

Analysed foundation sea surface temperature, global

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The through-cloud capabilities of microwave radiometers provide a valuable picture of global sea surface temperature (SST). To utilize this, scientists at Remote...

Multi-Annual Climate Predictions for Fisheries: An Assessment of Skill of Sea Surface Temperature Forecasts for Large Marine Ecosystems

Directory of Open Access Journals (Sweden)

Desiree Tommasi

2017-06-01

Full Text Available Decisions made by fishers and fisheries managers are informed by climate and fisheries observations that now often span more than 50 years. Multi-annual climate forecasts could further inform such decisions if they were skillful in predicting future conditions relative to the 50-year scope of past variability. We demonstrate that an existing multi-annual prediction system skillfully forecasts the probability of next year, the next 1–3 years, and the next 1–10 years being warmer or cooler than the 50-year average at the surface in coastal ecosystems. Probabilistic forecasts of upper and lower seas surface temperature (SST terciles over the next 3 or 10 years from the GFDL CM 2.1 10-member ensemble global prediction system showed significant improvements in skill over the use of a 50-year climatology for most Large Marine Ecosystems (LMEs in the North Atlantic, the western Pacific, and Indian oceans. Through a comparison of the forecast skill of initialized and uninitialized hindcasts, we demonstrate that this skill is largely due to the predictable signature of radiative forcing changes over the 50-year timescale rather than prediction of evolving modes of climate variability. North Atlantic LMEs stood out as the only coastal regions where initialization significantly contributed to SST prediction skill at the 1 to 10 year scale.

Effects of temperature and surface orientation on migration behaviours of helium atoms near tungsten surfaces

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaoshuang; Wu, Zhangwen; Hou, Qing, E-mail: qhou@scu.edu.cn

2015-10-15

Molecular dynamics simulations were performed to study the dependence of migration behaviours of single helium atoms near tungsten surfaces on the surface orientation and temperature. For W{100} and W{110} surfaces, He atoms can quickly escape out near the surface without accumulation even at a temperature of 400 K. The behaviours of helium atoms can be well-described by the theory of continuous diffusion of particles in a semi-infinite medium. For a W{111} surface, the situation is complex. Different types of trap mutations occur within the neighbouring region of the W{111} surface. The trap mutations hinder the escape of He atoms, resulting in their accumulation. The probability of a He atom escaping into vacuum from a trap mutation depends on the type of the trap mutation, and the occurrence probabilities of the different types of trap mutations are dependent on the temperature. This finding suggests that the escape rate of He atoms on the W{111} surface does not show a monotonic dependence on temperature. For instance, the escape rate at T = 1500 K is lower than the rate at T = 1100 K. Our results are useful for understanding the structural evolution and He release on tungsten surfaces and for designing models in other simulation methods beyond molecular dynamics.

Meteorology and climatology as parameters on low level waste disposal monitoring

International Nuclear Information System (INIS)

Culkowski, W.M.

1982-01-01

Once a site has been chosen for the burial of low level wastes, meteorological input is required in two forms, as climatology and as an estimator of airborne concentrations. The climatological data are fundamental to assessing hydrologic flow which may transport waste material from the original site. Airborne nuclear activity may occur by accidental release of material during the active burial phase or may result from gas formation in the trenches over a period of years

Estimation of the under-surface temperature pattern by dynamic remote sensing

Energy Technology Data Exchange (ETDEWEB)

Inamura, M [Univ. of Tokyo; Tao, R; Katsuma, T; Toyota, H

1977-10-01

There are three basic classifications of remote sensing: passive RS, which involves measurement of reflected solar radiation; active RS, which involves the use of microwaves or laser radar; and infrared scanning. These methods make possible the determination of an object's surface temperature, its effective emissivity, and its effective reflectivity. The surface temperature, in effect, contains information concerning the structure below the surface. Fundamental experiments were conducted to extract sub-surface information by means of 'dynamic remote sensing.' Aluminum objects were embedded in a container filled with sand, and the container was heated from below. First, the spatial transfer function of the medium (sand) was determined, the surface temperature pattern was filtered, and the subsurface temperature pattern was calculated, allowing the subsurface forms of the aluminum objects to be estimated. The relationship between the thermal input (bottom temperature) and the thermal output (surface temperature) was expressed in terms of electrical circuit analogs, and the heat capacity and thermal conductivity of the sample were calculated, permitting estimation of its composition. This technique will be useful for groundwater and mineral exploration and for nondestructive testing.

Afforestation in China cools local land surface temperature

OpenAIRE

Peng, Shu-Shi; Piao, Shilong; Zeng, Zhenzhong; Ciais, Philippe; Zhou, Liming; Li, Laurent Z. X.; Myneni, Ranga B.; Yin, Yi; Zeng, Hui

2014-01-01

International audience; China has the largest afforested area in the world (~62 million hectares in 2008), and these forests are carbon sinks. The climatic effect of these new forests depends on how radiant and turbulent energy fluxes over these plantations modify surface temperature. For instance, a lower albedo may cause warming, which negates the climatic benefits of carbon sequestration. Here, we used satellite measurements of land surface temperature (LST) from planted forests and adjace...

Hot surface temperatures of domestic appliances.

Science.gov (United States)

Bassett, Malcolm; Arild, Anne-Helene

2002-09-01

Domestic appliances are burning people. In the European Union, accidents requiring hospital treatment due to burns from hot objects account for between 0 and 1% of all such accidents. Young children are particularly at risk. These reported accidents requiring hospital treatment are also likely to be a small proportion of the total number of burns from hot objects. There is a lack of hard evidence about the level of accidents, typical consumer expectation and use, and on the state of the art of appliances. Results of technical laboratory tests carried out on products are used to demonstrate the state of the art and also show how consumer expectations could be changing. Results of a survey into accidents, based on a written questionnaire following telephone contact, provide information on non-hospital cases. Results of tests on products show that there are significant differences in the temperatures of touchable surfaces, even in products of the same type. Typically, these differences are due to variations in design and/or materials of construction. Some products are hot enough to burn skin. Accident research indicates that non-hospital medical practices are treating burn injuries, which are therefore not being included into the current accident statistics. For products with the same function, some types of design or materials of construction are safer, with lower surface temperatures. Many product standards have no or unnecessarily high limits on surface temperatures. Many standards do not address the realities of who is using their products, for what purpose or where they are located. Some standards use unreasonable general limitations and exclusions that allow products with higher surface temperatures than they should have. Many standards rely on the experience factor for avoiding injury that is no longer valid, with the increased availability of safer products of the same type. A major field of work ahead is to carry out more surveys and in-depth studies of non

Effects of landscape composition and pattern on land surface temperature: An urban heat island study in the megacities of Southeast Asia.

Science.gov (United States)

Estoque, Ronald C; Murayama, Yuji; Myint, Soe W

2017-01-15

Due to its adverse impacts on urban ecological environment and the overall livability of cities, the urban heat island (UHI) phenomenon has become a major research focus in various interrelated fields, including urban climatology, urban ecology, urban planning, and urban geography. This study sought to examine the relationship between land surface temperature (LST) and the abundance and spatial pattern of impervious surface and green space in the metropolitan areas of Bangkok (Thailand), Jakarta (Indonesia), and Manila (Philippines). Landsat-8 OLI/TIRS data and various geospatial approaches, including urban-rural gradient, multiresolution grid-based, and spatial metrics-based techniques, were used to facilitate the analysis. We found a significant strong correlation between mean LST and the density of impervious surface (positive) and green space (negative) along the urban-rural gradients of the three cities, depicting a typical UHI profile. The correlation of impervious surface density with mean LST tends to increase in larger grids, whereas the correlation of green space density with mean LST tends to increase in smaller grids, indicating a stronger influence of impervious surface and green space on the variability of LST in larger and smaller areas, respectively. The size, shape complexity, and aggregation of the patches of impervious surface and green space also had significant relationships with mean LST, though aggregation had the most consistent strong correlation. On average, the mean LST of impervious surface is about 3°C higher than that of green space, highlighting the important role of green spaces in mitigating UHI effects, an important urban ecosystem service. We recommend that the density and spatial pattern of urban impervious surfaces and green spaces be considered in landscape and urban planning so that urban areas and cities can have healthier and more comfortable living urban environments. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

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

Direct evaluation of transient surface temperatures and heat fluxes

International Nuclear Information System (INIS)

Axford, R.A.

1975-08-01

Evaluations of transient surface temperatures resulting from the absorption of radiation are required in laser fusion reactor systems studies. A general method for the direct evaluation of transient surface temperatures and heat fluxes on the boundaries of bounded media is developed by constructing fundamental solutions of the scalar Helmholtz equation and performing certain elementary integrations

A climatology of the California Current System from a network of underwater gliders

Science.gov (United States)

Rudnick, Daniel L.; Zaba, Katherine D.; Todd, Robert E.; Davis, Russ E.

2017-05-01

Autonomous underwater gliders offer the possibility of sustained observation of the coastal ocean. Since 2006 Spray underwater gliders in the California Underwater Glider Network (CUGN) have surveyed along California Cooperative Oceanic Fisheries Investigations (CalCOFI) lines 66.7, 80.0, and 90.0, constituting the world's longest sustained glider network, to our knowledge. In this network, gliders dive between the surface and 500 m, completing a cycle in 3 h and covering 3 km in that time. Sections extend 350-500 km offshore and take 2-3 weeks to occupy. Measured variables include pressure, temperature, salinity, and depth-average velocity. The CUGN has amassed over 10,000 glider-days, covering over 210,000 km with over 95,000 dives. These data are used to produce a climatology whose products are for each variable a mean field, an annual cycle, and the anomaly from the annual cycle. The analysis includes a weighted least-squares fit to derive the mean and annual cycle, and an objective map to produce the anomaly. The final results are variables on rectangular grids in depth, distance offshore, and time. The mean fields are finely resolved sections across the main flows in the California Current System, including the poleward California Undercurrent and the equatorward California Current. The annual cycle shows a phase change from the surface to the thermocline, reflecting the effects of air/sea fluxes at the surface and upwelling in the thermocline. The interannual anomalies are examined with an emphasis on climate events of the last ten years including the 2009-2010 El Niño, the 2010-2011 La Niña, the warm anomaly of 2014-2015, and the 2015-2016 El Niño.

Quantative determination of surface temperatures using an infrared camera

International Nuclear Information System (INIS)

Hsieh, C.K.; Ellingson, W.A.

1977-01-01

A method is presented to determine the surface-temperature distribution at each point in an infrared picture. To handle the surface reflection problem, three cases are considered that include the use of black coatings, radiation shields, and band-pass filters. For uniform irradiation on the test surface, the irradiation can be measured by using a cooled, convex mirror. Equations are derived to show that this surrounding irradiation effect can be subtracted out from the scanned radiation; thus the net radiation is related to only emission from the surface. To provide for temperature measurements over a large field, the image-processing technique is used to digitize the infrared data. The paper spells out procedures that involve the use of a computer for making point-by-point temperature calculations. Finally, a sample case is given to illustrate applications of the method. 6 figures, 1 table

Temperature impacts on the water year 2014 drought in California

Science.gov (United States)

Shukla, Shraddhanand; Safeeq, Mohammad; AghaKouchak, Amir; Guan, Kaiyu; Funk, Christopher C.

2015-01-01

California is experiencing one of the worst droughts on record. Here we use a hydrological model and risk assessment framework to understand the influence of temperature on the water year (WY) 2014 drought in California and examine the probability that this drought would have been less severe if temperatures resembled the historical climatology. Our results indicate that temperature played an important role in exacerbating the WY 2014 drought severity. We found that if WY 2014 temperatures resembled the 1916–2012 climatology, there would have been at least an 86% chance that winter snow water equivalent and spring-summer soil moisture and runoff deficits would have been less severe than the observed conditions. We also report that the temperature forecast skill in California for the important seasons of winter and spring is negligible, beyond a lead-time of one month, which we postulate might hinder skillful drought prediction in California.

evaluation of land surface temperature parameterization ...

African Journals Online (AJOL)

user

Surface temperature (Ts) is vital to the study of land-atmosphere interactions and ... representation of Ts in Global Climate Models using available ..... Obviously, the influence of the ambient .... diurnal cycle over land under clear and cloudy.

LOFT fuel rod surface temperature measurement testing

International Nuclear Information System (INIS)

Eaton, A.M.; Tolman, E.L.; Solbrig, C.W.

1978-01-01

Testing of the LOFT fuel rod cladding surface thermocouples has been performed to evaluate how accurately the LOFT thermocouples measure the cladding surface temperature during a loss-of-coolant accident (LOCA) sequence and what effect, if any, the thermocouple would have on core performance. Extensive testing has been done to characterize the thermocouple design. Thermal cycling and corrosion testing of the thermocouple weld design have provided an expected lifetime of 6000 hours when exposed to reactor coolant conditions of 620 K and 15.9 MPa and to sixteen thermal cycles with an initial temperature of 480 K and peak temperatures ranging from 870 to 1200K. Departure from nucleate boiling (DNB) tests have indicated a DNB penalty (5 to 28% lower) during steady state operation and negligible effects during LOCA blowdown caused by the LOFT fuel rod surface thermocouple arrangement. Experience with the thermocouple design in Power Burst Facility (PBF) and LOFT nonnuclear blowdown testing has been quite satisfactory. Tests discussed here were conducted using both stainless steel and zircaloy-clad electrically heated rod in the LOFT Test Support Facility (LTSF) blowdown simulation loop

Temperature-Responsive Anisotropic Slippery Surface for Smart Control of the Droplet Motion.

Science.gov (United States)

Wang, By Lili; Heng, Liping; Jiang, Lei

2018-02-28

Development of stimulus-responsive anisotropic slippery surfaces is important because of the high demand for such materials in the field of liquid directional-driven systems. However, current studies in the field of slippery surfaces are mainly conducted to prepare isotropic slippery surfaces. Although we have developed electric-responsive anisotropic slippery surfaces that enable smart control of the droplet motion, there remain challenges for designing temperature-responsive anisotropic slippery surfaces to control the liquid droplet motion on the surface and in the tube. In this work, temperature-responsive anisotropic slippery surfaces have been prepared by using paraffin, a thermo-responsive phase-transition material, as a lubricating fluid and directional porous polystyrene (PS) films as the substrate. The smart regulation of the droplet motion of several liquids on this surface was accomplished by tuning the substrate temperature. The uniqueness of this surface lies in the use of an anisotropic structure and temperature-responsive lubricating fluids to achieve temperature-driven smart control of the anisotropic motion of the droplets. Furthermore, this surface was used to design temperature-driven anisotropic microreactors and to manipulate liquid transfer in tubes. This work advances the understanding of the principles underlying anisotropic slippery surfaces and provides a promising material for applications in the biochip and microreactor system.

Sea Surface Temperature Average_SST_Master

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Sea surface temperature collected via satellite imagery from http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.html and averaged for each region using ArcGIS...

Two-Layer Variable Infiltration Capacity Land Surface Representation for General Circulation Models

Science.gov (United States)

Xu, L.

1994-01-01

A simple two-layer variable infiltration capacity (VIC-2L) land surface model suitable for incorporation in general circulation models (GCMs) is described. The model consists of a two-layer characterization of the soil within a GCM grid cell, and uses an aerodynamic representation of latent and sensible heat fluxes at the land surface. The effects of GCM spatial subgrid variability of soil moisture and a hydrologically realistic runoff mechanism are represented in the soil layers. The model was tested using long-term hydrologic and climatalogical data for Kings Creek, Kansas to estimate and validate the hydrological parameters. Surface flux data from three First International Satellite Land Surface Climatology Project Field Experiments (FIFE) intensive field compaigns in the summer and fall of 1987 in central Kansas, and from the Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) in Brazil were used to validate the mode-simulated surface energy fluxes and surface temperature.

Organic matter geochemical signatures (TOC, TN, C/N ratio, δ13C and δ15N) of surface sediment from lakes distributed along a climatological gradient on the western side of the southern Andes.

Science.gov (United States)

Contreras, Sergio; Werne, Josef P; Araneda, A; Urrutia, R; Conejero, C A

2018-07-15

Paleolimnological studies in western South America, where meteorological stations are scarce, are critical to obtain more realistic and reliable regional reconstructions of past climate and environmental changes, including vegetation and water budget variability. However, climate and environmental geochemical indicators must be tested before they can be applied with confidence. Here we present a survey of lacustrine surface sediment (core top, 0 to ~1cm) biogeochemical proxies (total organic carbon [TOC], total nitrogen [TN], carbon/nitrogen ratio [C/N ratio] and bulk organic δ 13 C and total δ 15 N) from a suite of 72 lakes spanning the transition from a Mediterranean climate with a patchwork of cultivated vegetation, pastureland, and conifers in central Chile to a rainy temperate climate dominated by broadleaf deciduous and evergreen forest further south. Sedimentary data are compared to the latitudinal and orographic climatic trends of the region based on the climatology (precipitation and temperature) produced with Climate Forecast System Reanalysis (CFSR) data and the modern Southern Hemisphere Westerly Winds (SWW) location. The geochemical data show inflection points at ~42°S latitude and ~1500m elevation that are likely related to the northern limit of influence of the SWW and elevation of the snow line, respectively. Overall the organic proxies were able to mimic climatic trends (Mean Annual Precipitation [MAP] and temperature [MAT]), indicating that they are a useful tool to be included in paleoclimatological reconstruction of the region. Copyright © 2018 Elsevier B.V. All rights reserved.

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.

Surface temperature measurement with radioactive kryptonates

International Nuclear Information System (INIS)

Pruzinec, J.; Piatrik, M.

1976-01-01

The preparation and use of radioactive kryptonates is described for measuring surface temperatures within the region of 45 to 70 degC. Two samples each were prepared of kryptonated beechwood and hydroquinone on a paper carrier. One sample served as the standard which during the experiment was placed in a thermostat at a constant temperature of 45 degC. The second sample was placed in another thermostat where the temperature changed from 45 to 70 degC. Both samples were in the thermostat for 30 mins. The temperature was raised in steps of 2.5 degC and the time of measurement was constant in both samples. The dependences are given of the drop in activity on temperature for both types of samples. The difference was determined of the drop in activity between the standard and the second sample and the relation for measuring the temperature of the sample was determined therefrom. (J.B.)

The GOCF/AWAP system - forecasting temperature extremes

International Nuclear Information System (INIS)

Fawcett, Robert; Hume, Timothy

2010-01-01

Gridded hourly temperature forecasts from the Bureau of Meteorology's Gridded Operational Consensus Forecasting (GOCF) system are combined in real time with the Australian Water Availability Project (AWAP) gridded daily temperature analyses to produce gridded daily maximum and minimum temperature forecasts with lead times from one to five days. These forecasts are compared against the historical record of AWAP daily temperature analyses (1911 to present), to identify regions where record or near-record temperatures are predicted to occur. This paper describes the GOCF/AWAP system, showing how the daily maximum and minimum temperature forecasts are prepared from the hourly forecasts, and how they are bias-corrected in real time using the AWAP analyses, against which they are subsequently verified. Using monthly climatologies of long-term daily mean, standard deviation and all-time highest and lowest on record, derived forecast products (for both maximum and minimum temperature) include ordinary and standardised anomalies, 'forecast - highest on record' and 'forecast - lowest on record'. Compensation for the climatological variation across the country is achieved in these last two products, which provide the necessary guidance as to whether or not record-breaking temperatures are expected, by expressing the forecast departure from the previous record in both 0 C and standard deviations.

Impact of Subsurface Temperature Variability on Meteorological Variability: An AGCM Study

Science.gov (United States)

Mahanama, S. P.; Koster, R. D.; Liu, P.

2006-05-01

Anomalous atmospheric conditions can lead to surface temperature anomalies, which in turn can lead to temperature anomalies deep in the soil. The deep soil temperature (and the associated ground heat content) has significant memory -- the dissipation of a temperature anomaly may take weeks to months -- and thus deep soil temperature may contribute to the low frequency variability of energy and water variables elsewhere in the system. The memory may even provide some skill to subseasonal and seasonal forecasts. This study uses two long-term AGCM experiments to isolate the contribution of deep soil temperature variability to variability elsewhere in the climate system. The first experiment consists of a standard ensemble of AMIP-type simulations, simulations in which the deep soil temperature variable is allowed to interact with the rest of the system. In the second experiment, the coupling of the deep soil temperature to the rest of the climate system is disabled -- at each grid cell, the local climatological seasonal cycle of deep soil temperature (as determined from the first experiment) is prescribed. By comparing the variability of various atmospheric quantities as generated in the two experiments, we isolate the contribution of interactive deep soil temperature to that variability. The results show that interactive deep soil temperature contributes significantly to surface temperature variability. Interactive deep soil temperature, however, reduces the variability of the hydrological cycle (evaporation and precipitation), largely because it allows for a negative feedback between evaporation and temperature.

Estimation of surface air temperature over central and eastern Eurasia from MODIS land surface temperature

International Nuclear Information System (INIS)

Shen Suhung; Leptoukh, Gregory G

2011-01-01

Surface air temperature (T a ) is a critical variable in the energy and water cycle of the Earth–atmosphere system and is a key input element for hydrology and land surface models. This is a preliminary study to evaluate estimation of T a from satellite remotely sensed land surface temperature (T s ) by using MODIS-Terra data over two Eurasia regions: northern China and fUSSR. High correlations are observed in both regions between station-measured T a and MODIS T s . The relationships between the maximum T a and daytime T s depend significantly on land cover types, but the minimum T a and nighttime T s have little dependence on the land cover types. The largest difference between maximum T a and daytime T s appears over the barren and sparsely vegetated area during the summer time. Using a linear regression method, the daily maximum T a were estimated from 1 km resolution MODIS T s under clear-sky conditions with coefficients calculated based on land cover types, while the minimum T a were estimated without considering land cover types. The uncertainty, mean absolute error (MAE), of the estimated maximum T a varies from 2.4 °C over closed shrublands to 3.2 °C over grasslands, and the MAE of the estimated minimum T a is about 3.0 °C.

Organismal climatology: analyzing environmental variability at scales relevant to physiological stress.

Science.gov (United States)

Helmuth, Brian; Broitman, Bernardo R; Yamane, Lauren; Gilman, Sarah E; Mach, Katharine; Mislan, K A S; Denny, Mark W

2010-03-15

Predicting when, where and with what magnitude climate change is likely to affect the fitness, abundance and distribution of organisms and the functioning of ecosystems has emerged as a high priority for scientists and resource managers. However, even in cases where we have detailed knowledge of current species' range boundaries, we often do not understand what, if any, aspects of weather and climate act to set these limits. This shortcoming significantly curtails our capacity to predict potential future range shifts in response to climate change, especially since the factors that set range boundaries under those novel conditions may be different from those that set limits today. We quantitatively examine a nine-year time series of temperature records relevant to the body temperatures of intertidal mussels as measured using biomimetic sensors. Specifically, we explore how a 'climatology' of body temperatures, as opposed to long-term records of habitat-level parameters such as air and water temperatures, can be used to extrapolate meaningful spatial and temporal patterns of physiological stress. Using different metrics that correspond to various aspects of physiological stress (seasonal means, cumulative temperature and the return time of extremes) we show that these potential environmental stressors do not always occur in synchrony with one another. Our analysis also shows that patterns of animal temperature are not well correlated with simple, commonly used metrics such as air temperature. Detailed physiological studies can provide guidance to predicting the effects of global climate change on natural ecosystems but only if we concomitantly record, archive and model environmental signals at appropriate scales.

Symmetric scaling properties in global surface air temperature anomalies

Science.gov (United States)

Varotsos, Costas A.; Efstathiou, Maria N.

2015-08-01

We have recently suggested "long-term memory" or internal long-range correlation within the time-series of land-surface air temperature (LSAT) anomalies in both hemispheres. For example, an increasing trend in the LSAT anomalies is followed by another one at a different time in a power-law fashion. However, our previous research was mainly focused on the overall long-term persistence, while in the present study, the upward and downward scaling dynamics of the LSAT anomalies are analysed, separately. Our results show that no significant fluctuation differences were found between the increments and decrements in LSAT anomalies, over the whole Earth and over each hemisphere, individually. On the contrary, the combination of land-surface air and sea-surface water temperature anomalies seemed to cause a departure from symmetry and the increments in the land and sea surface temperature anomalies appear to be more persistent than the decrements.

A model of the ground surface temperature for micrometeorological analysis

Science.gov (United States)

Leaf, Julian S.; Erell, Evyatar

2017-07-01

Micrometeorological models at various scales require ground surface temperature, which may not always be measured in sufficient spatial or temporal detail. There is thus a need for a model that can calculate the surface temperature using only widely available weather data, thermal properties of the ground, and surface properties. The vegetated/permeable surface energy balance (VP-SEB) model introduced here requires no a priori knowledge of soil temperature or moisture at any depth. It combines a two-layer characterization of the soil column following the heat conservation law with a sinusoidal function to estimate deep soil temperature, and a simplified procedure for calculating moisture content. A physically based solution is used for each of the energy balance components allowing VP-SEB to be highly portable. VP-SEB was tested using field data measuring bare loess desert soil in dry weather and following rain events. Modeled hourly surface temperature correlated well with the measured data (r 2 = 0.95 for a whole year), with a root-mean-square error of 2.77 K. The model was used to generate input for a pedestrian thermal comfort study using the Index of Thermal Stress (ITS). The simulation shows that the thermal stress on a pedestrian standing in the sun on a fully paved surface, which may be over 500 W on a warm summer day, may be as much as 100 W lower on a grass surface exposed to the same meteorological conditions.

Climatology and interannual variability of dynamic variables in multiple reanalyses evaluated by the SPARC Reanalysis Intercomparison Project (S-RIP)

Science.gov (United States)

Long, Craig S.; Fujiwara, Masatomo; Davis, Sean; Mitchell, Daniel M.; Wright, Corwin J.

2017-12-01

Two of the most basic parameters generated from a reanalysis are temperature and winds. Temperatures in the reanalyses are derived from conventional (surface and balloon), aircraft, and satellite observations. Winds are observed by conventional systems, cloud tracked, and derived from height fields, which are in turn derived from the vertical temperature structure. In this paper we evaluate as part of the SPARC Reanalysis Intercomparison Project (S-RIP) the temperature and wind structure of all the recent and past reanalyses. This evaluation is mainly among the reanalyses themselves, but comparisons against independent observations, such as HIRDLS and COSMIC temperatures, are also presented. This evaluation uses monthly mean and 2.5° zonal mean data sets and spans the satellite era from 1979-2014. There is very good agreement in temperature seasonally and latitudinally among the more recent reanalyses (CFSR, MERRA, ERA-Interim, JRA-55, and MERRA-2) between the surface and 10 hPa. At lower pressures there is increased variance among these reanalyses that changes with season and latitude. This variance also changes during the time span of these reanalyses with greater variance during the TOVS period (1979-1998) and less variance afterward in the ATOVS period (1999-2014). There is a distinct change in the temperature structure in the middle and upper stratosphere during this transition from TOVS to ATOVS systems. Zonal winds are in greater agreement than temperatures and this agreement extends to lower pressures than the temperatures. Older reanalyses (NCEP/NCAR, NCEP/DOE, ERA-40, JRA-25) have larger temperature and zonal wind disagreement from the more recent reanalyses. All reanalyses to date have issues analysing the quasi-biennial oscillation (QBO) winds. Comparisons with Singapore QBO winds show disagreement in the amplitude of the westerly and easterly anomalies. The disagreement with Singapore winds improves with the transition from TOVS to ATOVS observations

Climatology of increased temperatures and melt at Swiss Camp, western slope of Greenland ice sheet, 1991-2012

Science.gov (United States)

Steffen, K.; McGrath, D.

2013-12-01

Climate observations (1991-2012) will be discussed from the Swiss Camp (69deg 33‧53″N, 49deg 19‧51″W, 1176 m), located at the western slope of the Greenland ice sheet, 60 km inland from Ilulissat. The mean annual temperature of -12 C increased 3.6 C between 1991 and 2012 (1.7 C per decade) with large interannual variability in all seasons. The mean spring temperature increased from -16.0 C to -13.8 C, and the fall temperature increased from -12.4 C to -11.3 C in the same time. The winter temperature showed the largest increase of 6.5 C, whereas summer temperatures increased 3.0 C during the 21 years (1991 - 2012). Radiation has been monitored continuously at Swiss Camp since 1993. Net radiation of 50 W/ m2 was recorded in 2012, the warmest summer month on record. The entire annual snow cover melted at Swiss Camp, reducing the monthly albedo value to 0.4 with bare ice exposed. Interannual variability of snow accumulation ranged between 0.07 and 0.70 m water equivalent, whereas annual snow and ice ablation varied between +0.35 (net gain) and -1.8 m (net loss) for the time period 1991-2012. The equilibrium line altitude (ELA) is no longer located at Swiss Camp (1176 m elevation) with a net surface lowering of 9.5 m since 1991. Increasing summer air temperatures have resulted in an upward migration of both the percolation facies and ablation area of the Greenland ice sheet. The 0°C isothermal migrated upward at a rate of 35 m/a over the 1995-2012 period in West Greenland. There is a 50% probability of the mean annual dry snow line migrating above Summit by 2025, at which time Summit will experience routine melt on an annual basis. The surface mass balance observations similarly indicate that the ELA has migrated upwards at a rate of 44 m/a over the 1997-2011 period in West Greenland, resulting in a more than doubling of the ablation zone width during this period. Inter-annual variability of monthly mean albedo at the Swiss Camp (1993 - 2012). Albedo at 0.5 is

estimation of land surface temperature of kaduna metropolis, nigeria

African Journals Online (AJOL)

Zaharaddeen et. al

Land surface temperature can provide noteworthy information about the surface ... modelling the surface energy balance (Kalma, et al., 2008; ... Landsat, in addition some of the Landsat data have cloud cover and ..... The Impact Of Urban.

The application of low-rank and sparse decomposition method in the field of climatology

Science.gov (United States)

Gupta, Nitika; Bhaskaran, Prasad K.

2018-04-01

The present study reports a low-rank and sparse decomposition method that separates the mean and the variability of a climate data field. Until now, the application of this technique was limited only in areas such as image processing, web data ranking, and bioinformatics data analysis. In climate science, this method exactly separates the original data into a set of low-rank and sparse components, wherein the low-rank components depict the linearly correlated dataset (expected or mean behavior), and the sparse component represents the variation or perturbation in the dataset from its mean behavior. The study attempts to verify the efficacy of this proposed technique in the field of climatology with two examples of real world. The first example attempts this technique on the maximum wind-speed (MWS) data for the Indian Ocean (IO) region. The study brings to light a decadal reversal pattern in the MWS for the North Indian Ocean (NIO) during the months of June, July, and August (JJA). The second example deals with the sea surface temperature (SST) data for the Bay of Bengal region that exhibits a distinct pattern in the sparse component. The study highlights the importance of the proposed technique used for interpretation and visualization of climate data.

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...

Predicting monsoon rainfall and pressure indices from sea surface temperature

Digital Repository Service at National Institute of Oceanography (India)

Sadhuram, Y.

The relationship between the sea surface temperature (SST) in the Indian Ocean and monsoon rainfall has been examined by using 21 years data set (1967-87) of MOHSST.6 (Met. Office Historical Sea Surface Temperature data set, obtained from U.K. Met...

Diurnal Variations of Titan's Surface Temperatures From Cassini -CIRS Observations

Science.gov (United States)

Cottini, Valeria; Nixon, Conor; Jennings, Don; Anderson, Carrie; Samuelson, Robert; Irwin, Patrick; Flasar, F. Michael

The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 m (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the in-strument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature pro-file by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). The application of our methodology over wide areas has increased the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. In particular we had the chance to look for diurnal variations in surface temperature around the equator: a trend with slowly increasing temperature toward the late afternoon reveals that diurnal temperature changes are present on Titan surface. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp

Estonian total ozone climatology

Directory of Open Access Journals (Sweden)

K. Eerme

Full Text Available The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS data are discussed. The mean annual cycle during 1979–2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO corrected systematic decrease of total ozone from February–April was 3 ± 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of ± 20 DU and phase lag of 20 months. Between 1987–1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April–May and summer (June–August total ozone have the best correlation (coefficient 0.7 in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.

Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; volcanic effects – Meteorology and atmospheric dynamics (climatology

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.

[Study on Hollow Brick Wall's Surface Temperature with Infrared Thermal Imaging Method].

Science.gov (United States)

Tang, Ming-fang; Yin, Yi-hua

2015-05-01

To address the characteristic of uneven surface temperature of hollow brick wall, the present research adopts soft wares of both ThermaCAM P20 and ThermaCAM Reporter to test the application of infrared thermal image technique in measuring surface temperature of hollow brick wall, and further analyzes the thermal characteristics of hollow brick wall, and building material's impact on surface temperature distribution including hollow brick, masonry mortar, and so on. The research selects the construction site of a three-story-high residential, carries out the heat transfer experiment, and further examines the exterior wall constructed by 3 different hollow bricks including sintering shale hollow brick, masonry mortar and brick masonry. Infrared thermal image maps are collected, including 3 kinds of sintering shale hollow brick walls under indoor heating in winter; and temperature data of wall surface, and uniformity and frequency distribution are also collected for comparative analysis between 2 hollow bricks and 2 kinds of mortar masonry. The results show that improving heat preservation of hollow brick aid masonry mortar can effectively improve inner wall surface temperature and indoor thermal environment; non-uniformity of surface temperature decreases from 0. 6 to 0. 4 °C , and surface temperature frequency distribution changes from the asymmetric distribution into a normal distribution under the condition that energy-saving sintering shale hollow brick wall is constructed by thermal mortar replacing cement mortar masonry; frequency of average temperature increases as uniformity of surface temperature increases. This research provides a certain basis for promotion and optimization of hollow brick wall's thermal function.

Mathematical model of the metal mould surface temperature optimization

International Nuclear Information System (INIS)

Mlynek, Jaroslav; Knobloch, Roman; Srb, Radek

2015-01-01

The article is focused on the problem of generating a uniform temperature field on the inner surface of shell metal moulds. Such moulds are used e.g. in the automotive industry for artificial leather production. To produce artificial leather with uniform surface structure and colour shade the temperature on the inner surface of the mould has to be as homogeneous as possible. The heating of the mould is realized by infrared heaters located above the outer mould surface. The conceived mathematical model allows us to optimize the locations of infrared heaters over the mould, so that approximately uniform heat radiation intensity is generated. A version of differential evolution algorithm programmed in Matlab development environment was created by the authors for the optimization process. For temperate calculations software system ANSYS was used. A practical example of optimization of heaters locations and calculation of the temperature of the mould is included at the end of the article

Mathematical model of the metal mould surface temperature optimization

Energy Technology Data Exchange (ETDEWEB)

Mlynek, Jaroslav, E-mail: jaroslav.mlynek@tul.cz; Knobloch, Roman, E-mail: roman.knobloch@tul.cz [Department of Mathematics, FP Technical University of Liberec, Studentska 2, 461 17 Liberec, The Czech Republic (Czech Republic); Srb, Radek, E-mail: radek.srb@tul.cz [Institute of Mechatronics and Computer Engineering Technical University of Liberec, Studentska 2, 461 17 Liberec, The Czech Republic (Czech Republic)

2015-11-30

The article is focused on the problem of generating a uniform temperature field on the inner surface of shell metal moulds. Such moulds are used e.g. in the automotive industry for artificial leather production. To produce artificial leather with uniform surface structure and colour shade the temperature on the inner surface of the mould has to be as homogeneous as possible. The heating of the mould is realized by infrared heaters located above the outer mould surface. The conceived mathematical model allows us to optimize the locations of infrared heaters over the mould, so that approximately uniform heat radiation intensity is generated. A version of differential evolution algorithm programmed in Matlab development environment was created by the authors for the optimization process. For temperate calculations software system ANSYS was used. A practical example of optimization of heaters locations and calculation of the temperature of the mould is included at the end of the article.

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.

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.; Osipov, Sergey; Bantges, R.; Smirnov, A.; Banks, J.; Levy, R.; Jish Prakash, P.; Stenchikov, Georgiy L.

2015-01-01

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.

Analysis of Anomaly in Land Surface Temperature Using MODIS Products

Science.gov (United States)

Yorozu, K.; Kodama, T.; Kim, S.; Tachikawa, Y.; Shiiba, M.

2011-12-01

Atmosphere-land surface interaction plays a dominant role on the hydrologic cycle. Atmospheric phenomena cause variation of land surface state and land surface state can affect on atmosphereic conditions. Widely-known article related in atmospheric-land interaction was published by Koster et al. in 2004. The context of this article is that seasonal anomaly in soil moisture or soil surface temperature can affect summer precipitation generation and other atmospheric processes especially in middle North America, Sahel and south Asia. From not only above example but other previous research works, it is assumed that anomaly of surface state has a key factor. To investigate atmospheric-land surface interaction, it is necessary to analyze anomaly field in land surface state. In this study, soil surface temperature should be focused because it can be globally and continuously observed by satellite launched sensor. To land surface temperature product, MOD11C1 and MYD11C1 products which are kinds of MODIS products are applied. Both of them have 0.05 degree spatial resolution and daily temporal resolution. The difference of them is launched satellite, MOD11C1 is Terra and MYD11C1 is Aqua. MOD11C1 covers the latter of 2000 to present and MYD11C1 covers the early 2002 to present. There are unrealistic values on provided products even if daily product was already calibrated or corrected. For pre-analyzing, daily data is aggregated into 8-days data to remove irregular values for stable analysis. It was found that there are spatial and temporal distribution of 10-years average and standard deviation for each 8-days term. In order to point out extreme anomaly in land surface temperature, standard score for each 8-days term is applied. From the analysis of standard score, it is found there are large anomaly in land surface temperature around north China plain in early April 2005 and around Bangladesh in early May 2009.

The geological and climatological case for a warmer and wetter early Mars

Science.gov (United States)

Ramirez, Ramses M.; Craddock, Robert A.

2018-04-01

The climate of early Mars remains a topic of intense debate. Ancient terrains preserve landscapes consistent with stream channels, lake basins and possibly even oceans, and thus the presence of liquid water flowing on the Martian surface 4 billion years ago. However, despite the geological evidence, determining how long climatic conditions supporting liquid water lasted remains uncertain. Climate models have struggled to generate sufficiently warm surface conditions given the faint young Sun—even assuming a denser early atmosphere. A warm climate could have potentially been sustained by supplementing atmospheric CO2 and H2O warming with either secondary greenhouse gases or clouds. Alternatively, the Martian climate could have been predominantly cold and icy, with transient warming episodes triggered by meteoritic impacts, volcanic eruptions, methane bursts or limit cycles. Here, we argue that a warm and semi-arid climate capable of producing rain is most consistent with the geological and climatological evidence.

Simulated CONUS Flash Flood Climatologies from Distributed Hydrologic Models

Science.gov (United States)

Flamig, Z.; Gourley, J. J.; Vergara, H. J.; Kirstetter, P. E.; Hong, Y.

2016-12-01

This study will describe a CONUS flash flood climatology created over the period from 2002 through 2011. The MRMS reanalysis precipitation dataset was used as forcing into the Ensemble Framework For Flash Flood Forecasting (EF5). This high resolution 1-sq km 5-minute dataset is ideal for simulating flash floods with a distributed hydrologic model. EF5 features multiple water balance components including SAC-SMA, CREST, and a hydrophobic model all coupled with kinematic wave routing. The EF5/SAC-SMA and EF5/CREST water balance schemes were used for the creation of dual flash flood climatologies based on the differing water balance principles. For the period from 2002 through 2011 the daily maximum streamflow, unit streamflow, and time of peak streamflow was stored along with the minimum soil moisture. These variables are used to describe the states of the soils right before a flash flood event and the peak streamflow that was simulated during the flash flood event. The results will be shown, compared and contrasted. The resulting model simulations will be verified on basins less than 1,000-sq km with USGS gauges to ensure the distributed hydrologic models are reliable. The results will also be compared spatially to Storm Data flash flood event observations to judge the degree of agreement between the simulated climatologies and observations.

The climatology of the Red Sea - part 1: the wind

KAUST Repository

Langodan, Sabique

2017-05-12

The wind climatology of the Red Sea is described based on a 30-year high-resolution regional reanalysis generated using the Advanced Weather Research Forecasting model. The model was reinitialized on a daily basis with ERA-Interim global data and regional observations were assimilated using a cyclic three-dimensional variational approach. The reanalysis products were validated against buoy and scatterometers data. We describe the wind climatology and identify four major systems that determine the wind patterns in the Red Sea. Each system has a well-defined origin, and consequently different characteristics along the year. After analysing the relevant features of the basin in terms of their climatology, we investigate possible long-term trends in each system. It is found that there is a definite tendency towards lowering the strength of the wind speed, but at a different rate for different systems and periods of the year.

The climatology of the Red Sea - part 1: the wind

KAUST Repository

Langodan, Sabique; Cavaleri, Luigi; Vishwanadhapalli, Yesubabu; Pomaro, Angela; Bertotti, Luciana; Hoteit, Ibrahim

2017-01-01

The wind climatology of the Red Sea is described based on a 30-year high-resolution regional reanalysis generated using the Advanced Weather Research Forecasting model. The model was reinitialized on a daily basis with ERA-Interim global data and regional observations were assimilated using a cyclic three-dimensional variational approach. The reanalysis products were validated against buoy and scatterometers data. We describe the wind climatology and identify four major systems that determine the wind patterns in the Red Sea. Each system has a well-defined origin, and consequently different characteristics along the year. After analysing the relevant features of the basin in terms of their climatology, we investigate possible long-term trends in each system. It is found that there is a definite tendency towards lowering the strength of the wind speed, but at a different rate for different systems and periods of the year.

Measuring the Surface Temperature of the Cryosphere using Remote Sensing

Science.gov (United States)

Hall, Dorothy K.

2012-01-01

A general description of the remote sensing of cryosphere surface temperatures from satellites will be provided. This will give historical information on surface-temperature measurements from space. There will also be a detailed description of measuring the surface temperature of the Greenland Ice Sheet using Moderate-Resolution Imaging Spectroradiometer (MODIS) data which will be the focus of the presentation. Enhanced melting of the Greenland Ice Sheet has been documented in recent literature along with surface-temperature increases measured using infrared satellite data since 1981. Using a recently-developed climate data record, trends in the clear-sky ice-surface temperature (IST) of the Greenland Ice Sheet have been studied using the MODIS IST product. Daily and monthly MODIS ISTs of the Greenland Ice Sheet beginning on 1 March 2000 and continuing through 31 December 2010 are now freely available to download at 6.25-km spatial resolution on a polar stereographic grid. Maps showing the maximum extent of melt for the entire ice sheet and for the six major drainage basins have been developed from the MODIS IST dataset. Twelve-year trends of the duration of the melt season on the ice sheet vary in different drainage basins with some basins melting progressively earlier over the course of the study period. Some (but not all) of the basins also show a progressively-longer duration of melt. The consistency of this IST record, with temperature and melt records from other sources will be discussed.

Daily Cycle of Air Temperature and Surface Temperature in Stone Forest

Science.gov (United States)

Wang, K.; Li, Y.; Wang, X.; Yuan, M.

2013-12-01

Urbanization is one of the most profound human activities that impact on climate change. In cities, where are highly artificial areas, the conflict between human activity and natural climate is particularly prominent. Urban areas always have the larger area of impervious land, the higher consumption of greenhouse gases, more emissions of anthropogenic heat and air pollution, all contribute to the urban warming phenomena. Understanding the mechanisms causing a variety of phenomena involved in the urban warming is critical to distinguish the anthropogenic effect and natural variation in the climate change. However, the exact dynamics of urban warming were poorly understood, and effective control strategies are not available. Here we present a study of the daily cycle of air temperature and surface temperature in Stone Forest. The specific heat of the stones in the Stone Forest and concrete of the man-made structures within the cities are approximate. Besides, the height of the Stone Forest and the height of buildings within the city are also similar. As a scenic area, the Stone Forest is being preserved and only opened for sightseeing. There is no anthropogenic heat, as well air pollution within the Stone Forest. The thermal environment in Stone Forest can be considered to be a simulation of thermal environment in the city, which can reveal the effect of man-made structures on urban thermal environment. We conducted the field studies and numerical analysis in the Stone Forest for 4 typical urban morphology and environment scenarios, including high-rise compact cities, low-rise sparse cities, garden cities and isolated single stone. Air temperature and relative humidity were measured every half an hour in 15 different locations, which within different spatial distribution of stones and can represent the four urban scenarios respectively. At the same time, an infrared camera was used to take thermal images and get the hourly surface temperatures of stones and

Unexpected and Unexplained Surface Temperature Variations on Mimas

Science.gov (United States)

Howett, C.; Spencer, J. R.; Pearl, J. C.; Hurford, T. A.; Segura, M.; Cassini Cirs Team

2010-12-01

Until recently it was thought one of the most interesting things about Mimas, Saturn’s innermost classical icy moon, was its resemblance to Star Wars’ Death Star. However, a bizarre pattern of daytime surface temperatures was observed on Mimas using data obtained by Cassini’s Composite Infrared Spectrometer (CIRS) in February 2010. The observations were taken during Cassini’s closest ever encounter with Mimas (<10,000 km) and cover the daytime anti-Saturn hemisphere centered on longitude ~145° W. Instead of surface temperatures smoothly increasing throughout the morning and early afternoon, then cooling in the evening, as expected, a sharp V-shaped boundary is observed separating cooler midday and afternoon temperatures (~77 K) on the leading side from warmer morning temperatures (~92 K) on the trailing side. The boundary’s apex is centered at equatorial latitudes near the anti-Saturn point and extends to low north and south latitudes on the trailing side. Subtle differences in the surface colors have been observed that are roughly spatially correlated with the observed extent of the temperature anomaly, with the cooler regions tending to be bluer (Schenk et al., Submitted). However, visible-wavelength albedo is similar in the two regions, so albedo variations are probably not directly responsible for the thermal anomaly. It is more likely that thermal inertia variations produce the anomaly, with thermal inertia being unusually high in the region with anomalously low daytime temperatures. Comparison of the February 2010 CIRS data to previous lower spatial resolution data taken at different local times tentatively confirm that the cooler regions do indeed display higher thermal inertias. Bombardment of the surface by high energy electrons from Saturn’s radiation belts has been proposed to explain the observed color variations (Schenk et al., Submitted). Electrons above ~1 MeV preferentially impact Mimas’ leading hemisphere at low latitudes where they

Estimation of Surface Air Temperature Over Central and Eastern Eurasia from MODIS Land Surface Temperature

Science.gov (United States)

Shen, Suhung; Leptoukh, Gregory G.

2011-01-01

Surface air temperature (T(sub a)) is a critical variable in the energy and water cycle of the Earth.atmosphere system and is a key input element for hydrology and land surface models. This is a preliminary study to evaluate estimation of T(sub a) from satellite remotely sensed land surface temperature (T(sub s)) by using MODIS-Terra data over two Eurasia regions: northern China and fUSSR. High correlations are observed in both regions between station-measured T(sub a) and MODIS T(sub s). The relationships between the maximum T(sub a) and daytime T(sub s) depend significantly on land cover types, but the minimum T(sub a) and nighttime T(sub s) have little dependence on the land cover types. The largest difference between maximum T(sub a) and daytime T(sub s) appears over the barren and sparsely vegetated area during the summer time. Using a linear regression method, the daily maximum T(sub a) were estimated from 1 km resolution MODIS T(sub s) under clear-sky conditions with coefficients calculated based on land cover types, while the minimum T(sub a) were estimated without considering land cover types. The uncertainty, mean absolute error (MAE), of the estimated maximum T(sub a) varies from 2.4 C over closed shrublands to 3.2 C over grasslands, and the MAE of the estimated minimum Ta is about 3.0 C.

OW NOAA GOES-POES Sea Surface Temperature

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains blended satellite-derived sea-surface temperature measurements collected by means of the Geostationary Orbiting Environmental Satellites (GOES)...

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.

The international surface temperature initiative

Science.gov (United States)

Thorne, P. W.; Lawrimore, J. H.; Willett, K. M.; Allan, R.; Chandler, R. E.; Mhanda, A.; de Podesta, M.; Possolo, A.; Revadekar, J.; Rusticucci, M.; Stott, P. A.; Strouse, G. F.; Trewin, B.; Wang, X. L.; Yatagai, A.; Merchant, C.; Merlone, A.; Peterson, T. C.; Scott, E. M.

2013-09-01

The aim of International Surface Temperature Initiative is to create an end-to-end process for analysis of air temperature data taken over the land surface of the Earth. The foundation of any analysis is the source data. Land surface air temperature records have traditionally been stored in local, organizational, national and international holdings, some of which have been available digitally but many of which are available solely on paper or as imaged files. Further, economic and geopolitical realities have often precluded open sharing of these data. The necessary first step therefore is to collate readily available holdings and augment these over time either through gaining access to previously unavailable digital data or through data rescue and digitization activities. Next, it must be recognized that these historical measurements were made primarily in support of real-time weather applications where timeliness and coverage are key. At almost every long-term station it is virtually certain that changes in instrumentation, siting or observing practices have occurred. Because none of the historical measures were made in a metrologically traceable manner there is no unambiguous way to retrieve the true climate evolution from the heterogeneous raw data holdings. Therefore it is desirable for multiple independent groups to produce adjusted data sets (so-called homogenized data) to adequately understand the data characteristics and estimate uncertainties. Then it is necessary to benchmark the performance of the contributed algorithms (equivalent to metrological software validation) through development of realistic benchmark datasets. In support of this, a series of successive benchmarking and assessment cycles are envisaged, allowing continual improvement while avoiding over-tuning of algorithms. Finally, a portal is proposed giving access to related data-products, utilizing the assessment results to provide guidance to end-users on which product is the most suited to

Can human local activities worsen the rise of temperature due to Climate Change?

Science.gov (United States)

Mateos, E.; Santana, J.; Deeb, A.; Grünwaldt, A.; Prieto, R.

2013-12-01

Several studies have shown a global scale temperature rise which in consequence, have brought up the need to propose various impact scenarios for this change on the planet and its life forms. Climate changes have a direct effect on human activities. Particularly these alterations have a negative impact on economy which in turn affects the most vulnerable and marginal population on developing nations. In a recent study based on 30 years climatological observed temperature in ten Mexican watersheds, from the period between 1970 and 1999, positive trend on maximum temperature were found in all watersheds. At each watershed at least 10 climatological stations from the net operated by the National Meteorological Service (Servicio Meterologico Nacional), whose data are maintained in the CLICOM database (Computerized Climate database), were selected. The climatological stations have at least 70% valid data per decade. In eight watersheds a maximum temperature trend oscillates between +0.5 to +1 oC every 30 years with a 95% confidence level. Nonetheless, in Rio Bravo and Rio Verde watersheds the tendencies are +1.75 and +2.75 oC over 30 years. The result in these two last watersheds evinces that: 1) there are fragile systems; 2) the human activities have a strong impact in those places, and 3) a principal anthropogenic influence on temperature rise is the change in land use. Temperature rised on Jalostitlan within Rio Verde watershed

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.

Climatology and interannual variability of dynamic variables in multiple reanalyses evaluated by the SPARC Reanalysis Intercomparison Project (S-RIP

Directory of Open Access Journals (Sweden)

C. S. Long

2017-12-01

Full Text Available Two of the most basic parameters generated from a reanalysis are temperature and winds. Temperatures in the reanalyses are derived from conventional (surface and balloon, aircraft, and satellite observations. Winds are observed by conventional systems, cloud tracked, and derived from height fields, which are in turn derived from the vertical temperature structure. In this paper we evaluate as part of the SPARC Reanalysis Intercomparison Project (S-RIP the temperature and wind structure of all the recent and past reanalyses. This evaluation is mainly among the reanalyses themselves, but comparisons against independent observations, such as HIRDLS and COSMIC temperatures, are also presented. This evaluation uses monthly mean and 2.5° zonal mean data sets and spans the satellite era from 1979–2014. There is very good agreement in temperature seasonally and latitudinally among the more recent reanalyses (CFSR, MERRA, ERA-Interim, JRA-55, and MERRA-2 between the surface and 10 hPa. At lower pressures there is increased variance among these reanalyses that changes with season and latitude. This variance also changes during the time span of these reanalyses with greater variance during the TOVS period (1979–1998 and less variance afterward in the ATOVS period (1999–2014. There is a distinct change in the temperature structure in the middle and upper stratosphere during this transition from TOVS to ATOVS systems. Zonal winds are in greater agreement than temperatures and this agreement extends to lower pressures than the temperatures. Older reanalyses (NCEP/NCAR, NCEP/DOE, ERA-40, JRA-25 have larger temperature and zonal wind disagreement from the more recent reanalyses. All reanalyses to date have issues analysing the quasi-biennial oscillation (QBO winds. Comparisons with Singapore QBO winds show disagreement in the amplitude of the westerly and easterly anomalies. The disagreement with Singapore winds improves with the transition from

Three modes of interdecadal trends in sea surface temperature and sea surface height

Science.gov (United States)

Gnanadesikan, A.; Pradal, M.

2013-12-01

It might be thought that sea surface height and sea surface temperature would be tightly related. We show that this is not necessarily the case on a global scale. We analysed this relationship in a suite of coupled climate models run under 1860 forcing conditions. The models are low-resolution variants of the GFDL Earth System Model, reported in Galbraith et al. (J. Clim. 2011). 1. Correlated changes in global sea surface height and global sea surface temperature. This mode corresponds to opening and closing of convective chimneys in the Southern Ocean. As the Southern Ocean destratifies, sea ice formation is suppressed during the winter and more heat is taken up during the summer. This mode of variability is highly correlated with changes in the top of the atmosphere radiative budget and weakly correlated with changes in the deep ocean circulation. 2. Uncorrelated changes in global sea surface height and global sea surface temperature. This mode of variability is associated with interdecadal variabliity in tropical winds. Changes in the advective flux of heat to the surface ocean play a critical role in driving these changes, which also result in significant local changes in sea level. Changes sea ice over the Southern Ocean still result in changes in solar absorption, but these are now largely cancelled by changes in outgoing longwave radiation. 3. Anticorrelated changes in global sea surface height and global sea surface temperatures. By varying the lateral diffusion coefficient in the ocean model, we are able to enhance and suppress convection in the Southern and Northern Pacific Oceans. Increasing the lateral diffusion coefficients shifts the balance sources of deep water away from the warm salty deep water of the North Atlantic and towards cold fresh deep water from the other two regions. As a result, even though the planet as a whole warms, the deep ocean cools and sea level falls, with changes of order 30 cm over 500 years. The increase in solar absorption

Effect of design factors on surface temperature and wear in disk brakes

Science.gov (United States)

Santini, J. J.; Kennedy, F. E.; Ling, F. F.

1976-01-01

The temperatures, friction, wear and contact conditions that occur in high energy disk brakes are studied. Surface and near surface temperatures were monitored at various locations in a caliper disk brake during drag type testing, with friction coefficient and wear rates also being determined. The recorded transient temperature distributions in the friction pads and infrared photographs of the rotor disk surface both showed that contact at the friction surface was not uniform, with contact areas constantly shifting due to nonuniform thermal expansion and wear. The effect of external cooling and of design modifications on friction, wear and temperatures was also investigated. It was found that significant decreases in surface temperature and in wear rate can be achieved without a reduction in friction either by slotting the contacting face of the brake pad or by modifying the design of the pad support to improve pad compliance. Both design changes result in more uniform contact conditions on the friction surface.

A satellite and model based flood inundation climatology of Australia

Science.gov (United States)

Schumann, G.; Andreadis, K.; Castillo, C. J.

2013-12-01

To date there is no coherent and consistent database on observed or simulated flood event inundation and magnitude at large scales (continental to global). The only compiled data set showing a consistent history of flood inundation area and extent at a near global scale is provided by the MODIS-based Dartmouth Flood Observatory. However, MODIS satellite imagery is only available from 2000 and is hampered by a number of issues associated with flood mapping using optical images (e.g. classification algorithms, cloud cover, vegetation). Here, we present for the first time a proof-of-concept study in which we employ a computationally efficient 2-D hydrodynamic model (LISFLOOD-FP) complemented with a sub-grid channel formulation to generate a complete flood inundation climatology of the past 40 years (1973-2012) for the entire Australian continent. The model was built completely from freely available SRTM-derived data, including channel widths, bank heights and floodplain topography, which was corrected for vegetation canopy height using a global ICESat canopy dataset. Channel hydraulics were resolved using actual channel data and bathymetry was estimated within the model using hydraulic geometry. On the floodplain, the model simulated the flow paths and inundation variables at a 1 km resolution. The developed model was run over a period of 40 years and a floodplain inundation climatology was generated and compared to satellite flood event observations. Our proof-of-concept study demonstrates that this type of model can reliably simulate past flood events with reasonable accuracies both in time and space. The Australian model was forced with both observed flow climatology and VIC-simulated flows in order to assess the feasibility of a model-based flood inundation climatology at the global scale.

Benchmark analysis of forecasted seasonal temperature over different climatic areas

Science.gov (United States)

Giunta, G.; Salerno, R.; Ceppi, A.; Ercolani, G.; Mancini, M.

2015-12-01

From a long-term perspective, an improvement of seasonal forecasting, which is often exclusively based on climatology, could provide a new capability for the management of energy resources in a time scale of just a few months. This paper regards a benchmark analysis in relation to long-term temperature forecasts over Italy in the year 2010, comparing the eni-kassandra meteo forecast (e-kmf®) model, the Climate Forecast System-National Centers for Environmental Prediction (CFS-NCEP) model, and the climatological reference (based on 25-year data) with observations. Statistical indexes are used to understand the reliability of the prediction of 2-m monthly air temperatures with a perspective of 12 weeks ahead. The results show how the best performance is achieved by the e-kmf® system which improves the reliability for long-term forecasts compared to climatology and the CFS-NCEP model. By using the reliable high-performance forecast system, it is possible to optimize the natural gas portfolio and management operations, thereby obtaining a competitive advantage in the European energy market.

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,...

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,...

What model resolution is required in climatological downscaling over complex terrain?

Science.gov (United States)

El-Samra, Renalda; Bou-Zeid, Elie; El-Fadel, Mutasem

2018-05-01

This study presents results from the Weather Research and Forecasting (WRF) model applied for climatological downscaling simulations over highly complex terrain along the Eastern Mediterranean. We sequentially downscale general circulation model results, for a mild and wet year (2003) and a hot and dry year (2010), to three local horizontal resolutions of 9, 3 and 1 km. Simulated near-surface hydrometeorological variables are compared at different time scales against data from an observational network over the study area comprising rain gauges, anemometers, and thermometers. The overall performance of WRF at 1 and 3 km horizontal resolution was satisfactory, with significant improvement over the 9 km downscaling simulation. The total yearly precipitation from WRF's 1 km and 3 km domains exhibited quantitative measure of the potential errors for various hydrometeorological variables.

OW NOAA AVHRR-GAC Sea-Surface Temperature

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The dataset contains satellite-derived sea-surface temperature measurements collected by means of the Advanced Very High Resolution Radiometer - Global Area Coverage...

NASA/GEWEX Surface Radiation Budget: Integrated Data Product With Reprocessed Radiance, Cloud, and Meteorology Inputs, and New Surface Albedo Treatment

Science.gov (United States)

Cox, Stephen J.; Stackhouse, Paul W., Jr.; Gupta, Shashi K.; Mikovitz, J. Colleen; Zhang, Taiping

2016-01-01

The NASA/GEWEX Surface Radiation Budget (SRB) project produces shortwave and longwave surface and top of atmosphere radiative fluxes for the 1983-near present time period. Spatial resolution is 1 degree. The current release 3.0 (available at gewex-srb.larc.nasa.gov) uses the International Satellite Cloud Climatology Project (ISCCP) DX product for pixel level radiance and cloud information. This product is subsampled to 30 km. ISCCP is currently recalibrating and recomputing their entire data series, to be released as the H product, at 10km resolution. The ninefold increase in pixel number will allow SRB a higher resolution gridded product (e.g. 0.5 degree), as well as the production of pixel-level fluxes. In addition to the input data improvements, several important algorithm improvements have been made. Most notable has been the adaptation of Angular Distribution Models (ADMs) from CERES to improve the initial calculation of shortwave TOA fluxes, from which the surface flux calculations follow. Other key input improvements include a detailed aerosol history using the Max Planck Institut Aerosol Climatology (MAC), temperature and moisture profiles from HIRS, and new topography, surface type, and snow/ice. Here we present results for the improved GEWEX Shortwave and Longwave algorithm (GSW and GLW) with new ISCCP data, the various other improved input data sets and the incorporation of many additional internal SRB model improvements. As of the time of abstract submission, results from 2007 have been produced with ISCCP H availability the limiting factor. More SRB data will be produced as ISCCP reprocessing continues. The SRB data produced will be released as part of the Release 4.0 Integrated Product, recognizing the interdependence of the radiative fluxes with other GEWEX products providing estimates of the Earth's global water and energy cycle (I.e., ISCCP, SeaFlux, LandFlux, NVAP, etc.).

Multimodel Surface Temperature Responses to Removal of U.S. Sulfur Dioxide Emissions

Science.gov (United States)

Conley, A. J.; Westervelt, D. M.; Lamarque, J.-F.; Fiore, A. M.; Shindell, D.; Correa, G.; Faluvegi, G.; Horowitz, L. W.

2018-03-01

Three Earth System models are used to derive surface temperature responses to removal of U.S. anthropogenic SO2 emissions. Using multicentury perturbation runs with and without U.S. anthropogenic SO2 emissions, the local and remote surface temperature changes are estimated. In spite of a temperature drift in the control and large internal variability, 200 year simulations yield statistically significant regional surface temperature responses to the removal of U.S. SO2 emissions. Both local and remote surface temperature changes occur in all models, and the patterns of changes are similar between models for northern hemisphere land regions. We find a global average temperature sensitivity to U.S. SO2 emissions of 0.0055 K per Tg(SO2) per year with a range of (0.0036, 0.0078). We examine global and regional responses in SO4 burdens, aerosol optical depths (AODs), and effective radiative forcing (ERF). While changes in AOD and ERF are concentrated near the source region (United States), the temperature response is spread over the northern hemisphere with amplification of the temperature increase toward the Arctic. In all models, we find a significant response of dust concentrations, which affects the AOD but has no obvious effect on surface temperature. Temperature sensitivity to the ERF of U.S. SO2 emissions is found to differ from the models' sensitivity to radiative forcing of doubled CO2.

Functional inverted Wishart for Bayesian multivariate spatial modeling with application to regional climatology model data.

Science.gov (United States)

Duan, L L; Szczesniak, R D; Wang, X

2017-11-01

Modern environmental and climatological studies produce multiple outcomes at high spatial resolutions. Multivariate spatial modeling is an established means to quantify cross-correlation among outcomes. However, existing models typically suffer from poor computational efficiency and lack the flexibility to simultaneously estimate auto- and cross-covariance structures. In this article, we undertake a novel construction of covariance by utilizing spectral convolution and by imposing an inverted Wishart prior on the cross-correlation structure. The cross-correlation structure with this functional inverted Wishart prior flexibly accommodates not only positive but also weak or negative associations among outcomes while preserving spatial resolution. Furthermore, the proposed model is computationally efficient and produces easily interpretable results, including the individual autocovariances and full cross-correlation matrices, as well as a partial cross-correlation matrix reflecting the outcome correlation after excluding the effects caused by spatial convolution. The model is examined using simulated data sets under different scenarios. It is also applied to the data from the North American Regional Climate Change Assessment Program, examining long-term associations between surface outcomes for air temperature, pressure, humidity, and radiation, on the land area of the North American West Coast. Results and predictive performance are compared with findings from approaches using convolution only or coregionalization.

Functional inverted Wishart for Bayesian multivariate spatial modeling with application to regional climatology model data

Science.gov (United States)

Duan, L. L.; Szczesniak, R. D.; Wang, X.

2018-01-01

Modern environmental and climatological studies produce multiple outcomes at high spatial resolutions. Multivariate spatial modeling is an established means to quantify cross-correlation among outcomes. However, existing models typically suffer from poor computational efficiency and lack the flexibility to simultaneously estimate auto- and cross-covariance structures. In this article, we undertake a novel construction of covariance by utilizing spectral convolution and by imposing an inverted Wishart prior on the cross-correlation structure. The cross-correlation structure with this functional inverted Wishart prior flexibly accommodates not only positive but also weak or negative associations among outcomes while preserving spatial resolution. Furthermore, the proposed model is computationally efficient and produces easily interpretable results, including the individual autocovariances and full cross-correlation matrices, as well as a partial cross-correlation matrix reflecting the outcome correlation after excluding the effects caused by spatial convolution. The model is examined using simulated data sets under different scenarios. It is also applied to the data from the North American Regional Climate Change Assessment Program, examining long-term associations between surface outcomes for air temperature, pressure, humidity, and radiation, on the land area of the North American West Coast. Results and predictive performance are compared with findings from approaches using convolution only or coregionalization. PMID:29576735

Climatology of extratropical transition for North Atlantic tropical cyclones in the high-resolution GFDL climate model

Science.gov (United States)

Liu, M.; Vecchi, G. A.; Smith, J. A.

2015-12-01

The extratropical transition (ET) process of tropical cyclones can lead to fundamental changes in hurricane structure and storms that continue to pose large threats to life and properties. Given the importance of ET, it is necessary to understand how ET changes under a warming climate. Towards this goal, the GFDL climate model (FLOR) is first used to understand the current-day ET climatology. The standard model and a flux-adjusted version of FLOR are both used to examine ET climatology. The operational cyclone phase space method is used to define the onset and completion times of ET. The ET climatology from the climate model is compared with those from two reanalysis data sets ranging from 1979 to 2012. Both models exhibit good skills at simulating the frequency map of phase space diagram. The flux-adjusted version shows much better skill in capturing the ET climatology in terms of ET track patterns, ET locations and monthly ET variations. The model is able to simulate the frequency ratio of reintensified tropical cyclones from all ET cases. Future work involves examining changes in the ET climatology under a changing climate.

NOAA Daily Optimum Interpolation Sea Surface Temperature

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA 1/4° daily Optimum Interpolation Sea Surface Temperature (or daily OISST) is an analysis constructed by combining observations from different platforms...

[The reaction of human surface and inside body temperature to extreme hypothermia].

Science.gov (United States)

Panchenko, O A; Onishchenko, V O; Liakh, Iu Ie

2011-01-01

The dynamics of changes in the parameters of the surface and core body temperature under the systematic impact of ultra-low temperature is described in this article. As a source of ultra-low temperature was used (Cryo Therapy Chamber) Zimmer Medizin Systeme firm Zimmer Electromedizin (Germany) (-110 degrees C). Surface and internal body temperature was measured by infrared thermometer immediately before visiting cryochamber and immediately after exiting. In the study conducted 47,464 measurements of body temperature. It was established that the internal temperature of the human body under the influence of ultra-low temperatures in the proposed mode of exposure remains constant, and the surface temperature of the body reduces by an average of 11.57 degrees C. The time frame stabilization of adaptive processes of thermoregulation under the systematic impact of ultra-low temperature was defined in the study.

Global surface temperature in relation to northeast monsoon rainfall ...

Indian Academy of Sciences (India)

is observed that the meridional gradient in surface air temperature anomalies between Europe and ... Surface air tempera- ture is one of the factors that influence monsoon variability. The distribution of surface air temper- ature over land and sea determines the locations ..... Asia, north Indian Ocean, northeast Russia and.

Influence of the atomic structure of crystal surfaces on the surface diffusion in medium temperature range

International Nuclear Information System (INIS)

Cousty, J.P.

1981-12-01

In this work, we have studied the influence of atomic structure of crystal surface on surface self-diffusion in the medium temperature range. Two ways are followed. First, we have measured, using a radiotracer method, the self-diffusion coefficient at 820 K (0.6 T melting) on copper surfaces both the structure and the cleanliness of which were stable during the experiment. We have shown that the interaction between mobile surface defects and steps can be studied through measurements of the anisotropy of surface self diffusion. Second, the behavior of an adatom and a surface vacancy is simulated via a molecular dynamics method, on several surfaces of a Lennard Jones crystal. An inventory of possible migration mechanisms of these surface defects has been drawn between 0.35 and 0.45 Tsub(m). The results obtained with both the methods point out the influence of the surface atomic structure in surface self-diffusion in the medium temperature range [fr

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.;

Sea Surface Temperature (14 KM North America)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Product shows local sea surface temperatures (degrees C). It is a composite gridded-image derived from 8-km resolution SST Observations. It is generated every 48...

Fractal Dimension of Fracture Surface in Rock Material after High Temperature

Directory of Open Access Journals (Sweden)

Z. Z. Zhang

2015-01-01

Full Text Available Experiments on granite specimens after different high temperature under uniaxial compression were conducted and the fracture surfaces were observed by scanning electron microscope (SEM. The fractal dimensions of the fracture surfaces with increasing temperature were calculated, respectively. The fractal dimension of fracture surface is between 1.44 and 1.63. Its value approximately goes up exponentially with the increase of temperature. There is a quadratic polynomial relationship between the rockburst tendency and fractal dimension of fracture surface; namely, a fractal dimension threshold can be obtained. Below the threshold value, a positive correlativity shows between rockburst tendency and fractal dimension; when the fractal dimension is greater than the threshold value, it shows an inverse correlativity.

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)

The climatology of planetary boundary layer height in China derived from radiosonde and reanalysis data

Directory of Open Access Journals (Sweden)

J. Guo

2016-10-01

Full Text Available The important roles of the planetary boundary layer (PBL in climate, weather and air quality have long been recognized, but little is known about the PBL climatology in China. Using the fine-resolution sounding observations made across China and reanalysis data, we conducted a comprehensive investigation of the PBL in China from January 2011 to July 2015. The boundary layer height (BLH is found to be generally higher in spring and summer than that in fall and winter. The comparison of seasonally averaged BLHs derived from observations and reanalysis, on average, shows good agreement, despite the pronounced inconsistence in some regions. The BLH, derived from soundings conducted three or four times daily in summer, tends to peak in the early afternoon, and the diurnal amplitude of BLH is higher in the northern and western subregions of China than other subregions. The meteorological influence on the annual cycle of BLH is investigated as well, showing that BLH at most sounding sites is negatively associated with the surface pressure and lower tropospheric stability, but positively associated with the near-surface wind speed and temperature. In addition, cloud tends to suppress the development of PBL, particularly in the early afternoon. This indicates that meteorology plays a significant role in the PBL processes. Overall, the key findings obtained from this study lay a solid foundation for us to gain a deep insight into the fundamentals of PBL in China, which helps to understand the roles that the PBL plays in the air pollution, weather and climate of China.

Physically plausible prescription of land surface model soil moisture

Science.gov (United States)

Hauser, Mathias; Orth, René; Thiery, Wim; Seneviratne, Sonia

2016-04-01

Land surface hydrology is an important control of surface weather and climate, especially under extreme dry or wet conditions where it can amplify heat waves or floods, respectively. Prescribing soil moisture in land surface models is a valuable technique to investigate this link between hydrology and climate. It has been used for example to assess the influence of soil moisture on temperature variability, mean and extremes (Seneviratne et al. 2006, 2013, Lorenz et al., 2015). However, perturbing the soil moisture content artificially can lead to a violation of the energy and water balances. Here we present a new method for prescribing soil moisture which ensures water and energy balance closure by using only water from runoff and a reservoir term. If water is available, the method prevents soil moisture decrease below climatological values. Results from simulations with the Community Land Model (CLM) indicate that our new method allows to avoid soil moisture deficits in many regions of the world. We show the influence of the irrigation-supported soil moisture content on mean and extreme temperatures and contrast our findings with that of earlier studies. Additionally, we will assess how long into the 21st century the new method will be able to maintain present-day climatological soil moisture levels for different regions. Lorenz, R., Argüeso, D., Donat, M.G., Pitman, A.J., den Hurk, B.V., Berg, A., Lawrence, D.M., Chéruy, F., Ducharne, A., Hagemann, S. and Meier, A., 2015. Influence of land-atmosphere feedbacks on temperature and precipitation extremes in the GLACE-CMIP5 ensemble. Journal of Geophysical Research: Atmospheres. Seneviratne, S.I., Lüthi, D., Litschi, M. and Schär, C., 2006. Land-atmosphere coupling and climate change in Europe. Nature, 443(7108), pp.205-209. Seneviratne, S.I., Wilhelm, M., Stanelle, T., Hurk, B., Hagemann, S., Berg, A., Cheruy, F., Higgins, M.E., Meier, A., Brovkin, V. and Claussen, M., 2013. Impact of soil moisture

Urban surface temperature behaviour and heat island effect in a tropical planned city

Science.gov (United States)

Ahmed, Adeb Qaid; Ossen, Dilshan Remaz; Jamei, Elmira; Manaf, Norhashima Abd; Said, Ismail; Ahmad, Mohd Hamdan

2015-02-01

Putrajaya is a model city planned with concepts of a "city in the garden" and an "intelligent city" in the tropics. This study presents the behaviour of the surface temperature and the heat island effect of Putrajaya. Findings show that heat island intensity is 2 °C on average at nighttime and negligible at daytime. But high surface temperature values were recorded at the main boulevard due to direct solar radiation incident, street orientation in the direction of northeast and southwest and low building height-to-street width ratio. Buildings facing each other had cooling effect on surfaces during the morning and evening hours; conversely, they had a warming effect at noon. Clustered trees along the street are effective in reducing the surface temperature compared to scattered and isolated trees. Surface temperature of built up areas was highest at noon, while walls and sidewalks facing northwest were hottest later in the day. Walls and sidewalks that face northwest were warmer than those that face southeast. The surface temperatures of the horizontal street surfaces and of vertical façades are at acceptable levels relative to the surface temperature of similar surfaces in mature cities in subtropical, temperate and Mediterranean climates.

Some climatological factors of pine in the lake toba catchment area

Science.gov (United States)

Nasution, Z.

2018-02-01

The article deals with climatological factors of Pine at the Lake Toba Catchment Area also called drained basin, Pinus merkusii is a plant endemic in Sumatra. A central population of Pine in North Sumatra is located in the Tapanuli region to south of Lake Toba. Junghuhn discovered the species in the mountains range of Sipirok. He provisionally named the species as Pinus sumatrana. The article presents a detail analysis of approaches to climate factors, considers rainfall, air temperature, humidity, stemflow, throughfall and Interception following calculation of regression to determine relationship between precipitation with stemflow and interception. Stemflow, it is highly significant with significance of difference between correlation coefficients and z normal distribution. Temperature and relative humidity are the important components in the climate. These components influence the evaporation process and rainfall in the catchment. Pinus merkusii has the big crown interception. Stemflow and Interception has an opposite relation. Increasing of interception capacity will decrease stemflow. This type of Pine also has rough bark however significant channels so that, it flows water even during the wet season and caused the stemflow in Pinus merkusii relatively bigger.

Improving the performance of temperature index snowmelt model of SWAT by using MODIS land surface temperature data.

Science.gov (United States)

Yang, Yan; Onishi, Takeo; Hiramatsu, Ken

2014-01-01

Simulation results of the widely used temperature index snowmelt model are greatly influenced by input air temperature data. Spatially sparse air temperature data remain the main factor inducing uncertainties and errors in that model, which limits its applications. Thus, to solve this problem, we created new air temperature data using linear regression relationships that can be formulated based on MODIS land surface temperature data. The Soil Water Assessment Tool model, which includes an improved temperature index snowmelt module, was chosen to test the newly created data. By evaluating simulation performance for daily snowmelt in three test basins of the Amur River, performance of the newly created data was assessed. The coefficient of determination (R (2)) and Nash-Sutcliffe efficiency (NSE) were used for evaluation. The results indicate that MODIS land surface temperature data can be used as a new source for air temperature data creation. This will improve snow simulation using the temperature index model in an area with sparse air temperature observations.

Preparation and High-temperature Anti-adhesion Behavior of a Slippery Surface on Stainless Steel.

Science.gov (United States)

Zhang, Pengfei; Huawei, Chen; Liu, Guang; Zhang, Liwen; Zhang, Deyuan

2018-03-29

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A typical anti-wetting superhydrophobic surface easily fails when exposed to a high-temperature liquid. Recently, Nepenthes-inspired slippery surfaces demonstrated a new way to solve the adhesion problem. A lubricant layer on the slippery surface can act as a barrier between the repelled materials and the surface structure. However, the slippery surfaces in previous studies rarely showed high-temperature resistance. Here, we describe a protocol for the preparation of slippery surfaces with high-temperature resistance. A photolithography-assisted method was used to fabricate pillar structures on stainless steel. By functionalizing the surface with saline, a slippery surface was prepared by adding silicone oil. The prepared slippery surface maintained the anti-wetting property for water, even when the surface was heated to 300 °C. Also, the slippery surface exhibited great anti-adhesion effects on soft tissues at high temperatures. This type of slippery surface on stainless steel has applications in medical devices, mechanical equipment, etc.

Effects of high temperature surface oxides on room temperature aqueous corrosion and environmental embrittlement of iron aluminides

Energy Technology Data Exchange (ETDEWEB)

Buchanan, R.A.; Perrin, R.L.

1996-09-01

Studies were conducted to determine the effects of high-temperature surface oxides, produced during thermomechanical processing, heat treatment (750 {degrees}C in air, one hour) or simulated in-service-type oxidation (1000{degrees}C in air, 24 hours) on the room-temperature aqueous-corrosion and environmental-embrittlement characteristics of iron aluminides. Materials evaluated included the Fe{sub 3}Al-based iron aluminides, FA-84, FA-129, FAL and FAL-Mo, a FeAl-based iron aluminide, FA-385, and a disordered low-aluminum Fe-Al alloy, FAPY. Tests were performed in a mild acid-chloride solution to simulate aggressive atmospheric corrosion. Cyclic-anodic-polarization tests were employed to evaluate resistances to localized aqueous corrosion. The high-temperature oxide surfaces consistently produced detrimental results relative to mechanically or chemically cleaned surfaces. Specifically, the pitting corrosion resistances were much lower for the as-processed and 750{degrees} C surfaces, relative to the cleaned surfaces, for FA-84, FA-129, FAL-Mo, FA-385 and FAPY. Furthermore, the pitting corrosion resistances were much lower for the 1000{degrees}C surfaces, relative to cleaned surfaces, for FA-129, FAL and FAL-Mo.

High-fluence hyperthermal ion irradiation of gallium nitride surfaces at elevated temperatures

Energy Technology Data Exchange (ETDEWEB)

Finzel, A.; Gerlach, J.W., E-mail: juergen.gerlach@iom-leipzig.de; Lorbeer, J.; Frost, F.; Rauschenbach, B.

2014-10-30

Highlights: • Irradiation of gallium nitride films with hyperthermal nitrogen ions. • Surface roughening at elevated sample temperatures was observed. • No thermal decomposition of gallium nitride films during irradiation. • Asymmetric surface diffusion processes cause local roughening. - Abstract: Wurtzitic GaN films deposited on 6H-SiC(0001) substrates by ion-beam assisted molecular-beam epitaxy were irradiated with hyperthermal nitrogen ions with different fluences at different substrate temperatures. In situ observations with reflection high energy electron diffraction showed that during the irradiation process the surface structure of the GaN films changed from two dimensional to three dimensional at elevated temperatures, but not at room temperature. Atomic force microscopy revealed an enhancement of nanometric holes and canyons upon the ion irradiation at higher temperatures. The roughness of the irradiated and heated GaN films was clearly increased by the ion irradiation in accordance with x-ray reflectivity measurements. A sole thermal decomposition of the films at the chosen temperatures could be excluded. The results are discussed taking into account temperature dependent sputtering and surface uphill adatom diffusion as a function of temperature.

Extended-range forecasting of Chinese summer surface air temperature and heat waves

Science.gov (United States)

Zhu, Zhiwei; Li, Tim

2018-03-01

Because of growing demand from agricultural planning, power management and activity scheduling, extended-range (5-30-day lead) forecasting of summer surface air temperature (SAT) and heat waves over China is carried out in the present study via spatial-temporal projection models (STPMs). Based on the training data during 1960-1999, the predictability sources are found to propagate from Europe, Northeast Asia, and the tropical Pacific, to influence the intraseasonal 10-80 day SAT over China. STPMs are therefore constructed using the projection domains, which are determined by these previous predictability sources. For the independent forecast period (2000-2013), the STPMs can reproduce EOF-filtered 30-80 day SAT at all lead times of 5-30 days over most part of China, and observed 30-80 and 10-80 day SAT at 25-30 days over eastern China. Significant pattern correlation coefficients account for more than 50% of total forecasts at all 5-30-day lead times against EOF-filtered and observed 30-80 day SAT, and at a 20-day lead time against observed 10-80 day SAT. The STPMs perform poorly in reproducing 10-30 day SAT. Forecasting for the first two modes of 10-30 day SAT only shows useful skill within a 15-day lead time. Forecasting for the third mode of 10-30 day SAT is useless after a 10-day lead time. The forecasted heat waves over China are determined by the reconstructed SAT which is the summation of the forecasted 10-80 day SAT and the lower frequency (longer than 80-day) climatological SAT. Over a large part of China, the STPMs can forecast more than 30% of heat waves within a 15-day lead time. In general, the STPMs demonstrate the promising skill for extended-range forecasting of Chinese summer SAT and heat waves.

Effect of land model ensemble versus coupled model ensemble on the simulation of precipitation climatology and variability

Science.gov (United States)

Wei, Jiangfeng; Dirmeyer, Paul A.; Yang, Zong-Liang; Chen, Haishan

2017-10-01

Through a series of model simulations with an atmospheric general circulation model coupled to three different land surface models, this study investigates the impacts of land model ensembles and coupled model ensemble on precipitation simulation. It is found that coupling an ensemble of land models to an atmospheric model has a very minor impact on the improvement of precipitation climatology and variability, but a simple ensemble average of the precipitation from three individually coupled land-atmosphere models produces better results, especially for precipitation variability. The generally weak impact of land processes on precipitation should be the main reason that the land model ensembles do not improve precipitation simulation. However, if there are big biases in the land surface model or land surface data set, correcting them could improve the simulated climate, especially for well-constrained regional climate simulations.

The Effect of Bond Albedo on Venus' Atmospheric and Surface Temperatures

Science.gov (United States)

Bullock, M. A.; Limaye, S. S.; Grinspoon, D. H.; Way, M.

2017-12-01

In spite of Venus' high planetary albedo, sufficient solar energy reaches the surface to drive a powerful greenhouse effect. The surface temperature is three times higher than it would be without an atmosphere. However, the details of the energy balance within Venus' atmosphere are poorly understood. Half of the solar energy absorbed within the clouds, where most of the solar energy is absorbed, is due to an unknown agent. One of the challenges of modeling Venus' atmosphere has been to account for all the sources of opacity sufficient to generate a globally averaged surface temperature of 735 K, when only 2% of the incoming solar energy is deposited at the surface. The wavelength and spherically integrated albedo, or Bond albedo, has typically been cited as between 0.7 and 0.82 (Colin 1983). Yet, recent photometry of Venus at extended phase angles between 2 and 179° indicate a Bond albedo of 0.90 (Mallama et al., 2006). The authors note an increase in cloud top brightness at phase angles fixed. Figure 1b (right). Venus surface temperature as Bond Albedo changes. Radiative-convective equilibrium models predict the correct globally averaged surface temperature at a=0.81. Calculations here show that a Bond albedo of a=0.9 would yield a surface temperature of 666.4 K, about 70 K too low, unless there is additional thermal absorption within the atmosphere that is not understood. Colin, L.,, Venus, University of Arizona Press, Tucson, 1983, pp 10-26. Mallama, A., et al., 2006. Icarus. 182, 10-22.

Biomes computed from simulated climatologies

Energy Technology Data Exchange (ETDEWEB)

Claussen, M.; Esch, M. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

1994-01-01

The biome model of Prentice et al. is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fuer Meteorologie. This study undertaken in order to show the advantage of this biome model in diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to in simulated rainfall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are for the tropical rain forests. A potential northeast shift of biomes is expected from a simulation with enhanced CO{sub 2} concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting chances in vegetation patterns due to a rapid climate change, the latter simulation to be taken as a prediction of chances in conditions favourable for the existence of certain biomes, not as a reduction of a future distribution of biomes. 15 refs., 8 figs., 2 tabs.

Global Land Surface Temperature From the Along-Track Scanning Radiometers

Science.gov (United States)

Ghent, D. J.; Corlett, G. K.; Göttsche, F.-M.; Remedios, J. J.

2017-11-01

The Leicester Along-Track Scanning Radiometer (ATSR) and Sea and Land Surface Temperature Radiometer (SLSTR) Processor for LAnd Surface Temperature (LASPLAST) provides global land surface temperature (LST) products from thermal infrared radiance data. In this paper, the state-of-the-art version of LASPLAST, as deployed in the GlobTemperature project, is described and applied to data from the Advanced Along-Track Scanning Radiometer (AATSR). The LASPLAST retrieval formulation for LST is a nadir-only, two-channel, split-window algorithm, based on biome classification, fractional vegetation, and across-track water vapor dependences. It incorporates globally robust retrieval coefficients derived using highly sampled atmosphere profiles. LASPLAST benefits from appropriate spatial resolution auxiliary information and a new probabilistic-based cloud flagging algorithm. For the first time for a satellite-derived LST product, pixel-level uncertainties characterized in terms of random, locally correlated, and systematic components are provided. The new GlobTemperature GT_ATS_2P Version 1.0 product has been validated for 1 year of AATSR data (2009) against in situ measurements acquired from "gold standard reference" stations: Gobabeb, Namibia, and Evora, Portugal; seven Surface Radiation Budget stations, and the Atmospheric Radiation Measurement station at Southern Great Plains. These data show average absolute biases for the GT_ATS_2P Version 1.0 product of 1.00 K in the daytime and 1.08 K in the nighttime. The improvements in data provenance including better accuracy, fully traceable retrieval coefficients, quantified uncertainty, and more detailed information in the new harmonized format of the GT_ATS_2P product will allow for more significant exploitation of the historical LST data record from the ATSRs and a valuable near-real-time service from the Sea and Land Surface Temperature Radiometers (SLSTRs).

An A-Train Climatology of Extratropical Cyclone Clouds

Science.gov (United States)

Posselt, Derek J.; van den Heever, Susan C.; Booth, James F.; Del Genio, Anthony D.; Kahn, Brian; Bauer, Mike

2016-01-01

Extratropical cyclones (ETCs) are the main purveyors of precipitation in the mid-latitudes, especially in winter, and have a significant radiative impact through the clouds they generate. However, general circulation models (GCMs) have trouble representing precipitation and clouds in ETCs, and this might partly explain why current GCMs disagree on to the evolution of these systems in a warming climate. Collectively, the A-train observations of MODIS, CloudSat, CALIPSO, AIRS and AMSR-E have given us a unique perspective on ETCs: over the past 10 years these observations have allowed us to construct a climatology of clouds and precipitation associated with these storms. This has proved very useful for model evaluation as well in studies aimed at improving understanding of moist processes in these dynamically active conditions. Using the A-train observational suite and an objective cyclone and front identification algorithm we have constructed cyclone centric datasets that consist of an observation-based characterization of clouds and precipitation in ETCs and their sensitivity to large scale environments. In this presentation, we will summarize the advances in our knowledge of the climatological properties of cloud and precipitation in ETCs acquired with this unique dataset. In particular, we will present what we have learned about southern ocean ETCs, for which the A-train observations have filled a gap in this data sparse region. In addition, CloudSat and CALIPSO have for the first time provided information on the vertical distribution of clouds in ETCs and across warm and cold fronts. We will also discuss how these observations have helped identify key areas for improvement in moist processes in recent GCMs. Recently, we have begun to explore the interaction between aerosol and cloud cover in ETCs using MODIS, CloudSat and CALIPSO. We will show how aerosols are climatologically distributed within northern hemisphere ETCs, and how this relates to cloud cover.

Inverse estimation for temperatures of outer surface and geometry of inner surface of furnace with two layer walls

International Nuclear Information System (INIS)

Chen, C.-K.; Su, C.-R.

2008-01-01

This study provides an inverse analysis to estimate the boundary thermal behavior of a furnace with two layer walls. The unknown temperature distribution of the outer surface and the geometry of the inner surface were estimated from the temperatures of a small number of measured points within the furnace wall. The present approach rearranged the matrix forms of the governing differential equations and then combined the reversed matrix method, the linear least squares error method and the concept of virtual area to determine the unknown boundary conditions of the furnace system. The dimensionless temperature data obtained from the direct problem were used to simulate the temperature measurements. The influence of temperature measurement errors upon the precision of the estimated results was also investigated. The advantage of this approach is that the unknown condition can be directly solved by only one calculation process without initially guessed temperatures, and the iteration process of the traditional method can be avoided in the analysis of the heat transfer. Therefore, the calculation in this work is more rapid and exact than the traditional method. The result showed that the estimation error of the geometry increased with increasing distance between measured points and inner surface and in preset error, and with decreasing number of measured points. However, the geometry of the furnace inner surface could be successfully estimated by only the temperatures of a small number of measured points within and near the outer surface under reasonable preset error

Spatial-temporal analysis of building surface temperatures in Hung Hom

Science.gov (United States)

Zeng, Ying; Shen, Yueqian

2015-12-01

This thesis presents a study on spatial-temporal analysis of building surface temperatures in Hung Hom. Observations were collected from Aug 2013 to Oct 2013 at a 30-min interval, using iButton sensors (N=20) covering twelve locations in Hung Hom. And thermal images were captured in PolyU from 05 Aug 2013 to 06 Aug 2013. A linear regression model of iButton and thermal records is established to calibrate temperature data. A 3D modeling system is developed based on Visual Studio 2010 development platform, using ArcEngine10.0 component, Microsoft Access 2010 database and C# programming language. The system realizes processing data, spatial analysis, compound query and 3D face temperature rendering and so on. After statistical analyses, building face azimuths are found to have a statistically significant relationship with sun azimuths at peak time. And seasonal building temperature changing also corresponds to the sun angle and sun azimuth variations. Building materials are found to have a significant effect on building surface temperatures. Buildings with lower albedo materials tend to have higher temperatures and larger thermal conductivity material have significant diurnal variations. For the geographical locations, the peripheral faces of campus have higher temperatures than the inner faces during day time and buildings located at the southeast are cooler than the western. Furthermore, human activity is found to have a strong relationship with building surface temperatures through weekday and weekend comparison.

Climate change impact of livestock CH4 emission in India: Global temperature change potential (GTP) and surface temperature response.

Science.gov (United States)

Kumari, Shilpi; Hiloidhari, Moonmoon; Kumari, Nisha; Naik, S N; Dahiya, R P

2018-01-01

Two climate metrics, Global surface Temperature Change Potential (GTP) and the Absolute GTP (AGTP) are used for studying the global surface temperature impact of CH 4 emission from livestock in India. The impact on global surface temperature is estimated for 20 and 100 year time frames due to CH 4 emission. The results show that the CH 4 emission from livestock, worked out to 15.3 Tg in 2012. In terms of climate metrics GTP of livestock-related CH 4 emission in India in 2012 were 1030 Tg CO 2 e (GTP 20 ) and 62 Tg CO 2 e (GTP 100 ) at the 20 and 100 year time horizon, respectively. The study also illustrates that livestock-related CH 4 emissions in India can cause a surface temperature increase of up to 0.7mK and 0.036mK over the 20 and 100 year time periods, respectively. The surface temperature response to a year of Indian livestock emission peaks at 0.9mK in the year 2021 (9 years after the time of emission). The AGTP gives important information in terms of temperature change due to annual CH 4 emissions, which is useful when comparing policies that address multiple gases. Copyright © 2017 Elsevier Inc. All rights reserved.

"Intelligent Ensemble" Projections of Precipitation and Surface Radiation in Support of Agricultural Climate Change Adaptation

Science.gov (United States)

Taylor, Patrick C.; Baker, Noel C.

2015-01-01

Earth's climate is changing and will continue to change into the foreseeable future. Expected changes in the climatological distribution of precipitation, surface temperature, and surface solar radiation will significantly impact agriculture. Adaptation strategies are, therefore, required to reduce the agricultural impacts of climate change. Climate change projections of precipitation, surface temperature, and surface solar radiation distributions are necessary input for adaption planning studies. These projections are conventionally constructed from an ensemble of climate model simulations (e.g., the Coupled Model Intercomparison Project 5 (CMIP5)) as an equal weighted average, one model one vote. Each climate model, however, represents the array of climate-relevant physical processes with varying degrees of fidelity influencing the projection of individual climate variables differently. Presented here is a new approach, termed the "Intelligent Ensemble, that constructs climate variable projections by weighting each model according to its ability to represent key physical processes, e.g., precipitation probability distribution. This approach provides added value over the equal weighted average method. Physical process metrics applied in the "Intelligent Ensemble" method are created using a combination of NASA and NOAA satellite and surface-based cloud, radiation, temperature, and precipitation data sets. The "Intelligent Ensemble" method is applied to the RCP4.5 and RCP8.5 anthropogenic climate forcing simulations within the CMIP5 archive to develop a set of climate change scenarios for precipitation, temperature, and surface solar radiation in each USDA Farm Resource Region for use in climate change adaptation studies.

Coherent changes of wintertime surface air temperatures over North Asia and North America.

Science.gov (United States)

Yu, Bin; Lin, Hai

2018-03-29

The surface temperature variance and its potential change with global warming are most prominent in winter over Northern Hemisphere mid-high latitudes. Consistent wintertime surface temperature variability has been observed over large areas in Eurasia and North America on a broad range of time scales. However, it remains a challenge to quantify where and how the coherent change of temperature anomalies occur over the two continents. Here we demonstrate the coherent change of wintertime surface temperature anomalies over North Asia and the central-eastern parts of North America for the period from 1951 to 2015. This is supported by the results from the empirical orthogonal function analysis of surface temperature and temperature trend anomalies over the Northern Hemisphere extratropical lands and the timeseries analysis of the regional averaged temperature anomalies over North Asia and the Great Plains and Great Lakes. The Asian-Bering-North American (ABNA) teleconnection provides a pathway to connect the regional temperature anomalies over the two continents. The ABNA is also responsible for the decadal variation of the temperature relationship between North Asia and North America.