WorldWideScience

Sample records for oasis ocean atmosphere

  1. A Reusable and Autonomous Ocean-Atmosphere Sensor Integration System (OASIS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The need to acquire observations on oceanic and atmospheric physical and biogeochemical processes continues to increase. These data are presently being used as...

  2. Hydrodynamics of oceans and atmospheres

    CERN Document Server

    Eckart, Carl

    1960-01-01

    Hydrodynamics of Oceans and Atmospheres is a systematic account of the hydrodynamics of oceans and atmospheres. Topics covered range from the thermodynamic functions of an ideal gas and the thermodynamic coefficients for water to steady motions, the isothermal atmosphere, the thermocline, and the thermosphere. Perturbation equations, field equations, residual equations, and a general theory of rays are also presented. This book is comprised of 17 chapters and begins with an introduction to the basic equations and their solutions, with the aim of illustrating the laws of dynamics. The nonlinear

  3. Oceanic Area System Improvement Study (OASIS). Volume IV. Caribbean Region Air Traffic Services System Description.

    Science.gov (United States)

    1981-09-01

    OASIS) U Final Report This report i.s one of a set of companion documents which includes the following volumes: Volume I Executive Summary and...Northern Coastal Region of 4 the Directorate of Engineering and Systems (Direccion de Ingenieria y Sistemas ), which is responsible for maintenance of the

  4. The atmosphere and ocean: A physical introduction

    International Nuclear Information System (INIS)

    Wells, N.

    1986-01-01

    The book's contents are: The Earth within the solar system. Composition and physical properties of the ocean and atmosphere. Radiation, temperature and stability. Water in the atmosphere. Global budgets of heat, water and salt. Observations of winds and currents. The influence of the Earth's rotation on fluid motion. Waves and tides. Energy transfer in the ocean-atmosphere system. Climate variability and predictability. The atmosphere and ocean are two different environmental systems, yet both are interdependent, interacting and exchanging energy, heat and matter. This book attempts to bring the study of the atmosphere and ocean together. It is a descriptive account of physical properties, exploring their common bases, similarities, interactions and fundamental differences

  5. LIGHT SCATTERING FROM EXOPLANET OCEANS AND ATMOSPHERES

    International Nuclear Information System (INIS)

    Zugger, M. E.; Kane, T. J.; Kasting, J. F.; Williams, D. M.; Philbrick, C. R.

    2010-01-01

    Orbital variation in reflected starlight from exoplanets could eventually be used to detect surface oceans. Exoplanets with rough surfaces, or dominated by atmospheric Rayleigh scattering, should reach peak brightness in full phase, orbital longitude (OL) = 180 0 , whereas ocean planets with transparent atmospheres should reach peak brightness in crescent phase near OL = 30 0 . Application of Fresnel theory to a planet with no atmosphere covered by a calm ocean predicts a peak polarization fraction of 1 at OL = 74 0 ; however, our model shows that clouds, wind-driven waves, aerosols, absorption, and Rayleigh scattering in the atmosphere and within the water column dilute the polarization fraction and shift the peak to other OLs. Observing at longer wavelengths reduces the obfuscation of the water polarization signature by Rayleigh scattering but does not mitigate the other effects. Planets with thick Rayleigh scattering atmospheres reach peak polarization near OL = 90 0 , but clouds and Lambertian surface scattering dilute and shift this peak to smaller OL. A shifted Rayleigh peak might be mistaken for a water signature unless data from multiple wavelength bands are available. Our calculations suggest that polarization alone may not positively identify the presence of an ocean under an Earth-like atmosphere; however, polarization adds another dimension which can be used, in combination with unpolarized orbital light curves and contrast ratios, to detect extrasolar oceans, atmospheric water aerosols, and water clouds. Additionally, the presence and direction of the polarization vector could be used to determine planet association with the star, and constrain orbit inclination.

  6. 77 FR 33443 - National Oceanic and Atmospheric Administration

    Science.gov (United States)

    2012-06-06

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Pacific Fishery Management Council; Public Meeting AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION: Notice of public meeting. SUMMARY: The panel to review assessment...

  7. The Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS)

    National Research Council Canada - National Science Library

    Hodur, Richard M; Hong, Xiaodong; Doyle, James D; Pullen, Julie; Cummings, James; Martin, Paul; Rennick, Mary Alice

    2002-01-01

    ... of the Couple Ocean/Atmosphere Mesoscale Prediction System (COAMPS). The goal of this modeling project is to gain predictive skill in simulating the ocean and atmosphere at high resolution on time-scales of hours to several days...

  8. Atmosphere-Ocean Coupling through Trace Gases

    Science.gov (United States)

    Tegtmeier, S.; Atlas, E. L.; Krüger, K.; Lennartz, S. T.; Marandino, C. A.; Patra, P. K.; Quack, B.; Schlundt, C.

    2017-12-01

    Halogen- and sulfur-containing trace gases, as well as other volatile organic compounds (VOCs, such as isoprene) from biogeochemical marine sources are important constituents of the ocean and the atmosphere. These compounds exert wide-ranging influence on atmospheric chemical processes and climate interactions, as well as on human health in coastal regions. In their reactive form, they can affect the oxidizing capacity of the air and lead to the formation of new particles or the growth of existing ones. In this contribution, marine derived halogen-, sulfur-, and oxygen-containing compounds will be discussed. Their net flux into the atmosphere and their impact on atmospheric processes is analyzed based on observations and model simulations.

  9. 76 FR 65183 - National Oceanic and Atmospheric Administration

    Science.gov (United States)

    2011-10-20

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Climate Assessment... Oceanic and Atmospheric Administration (NOAA), Department of Commerce (DOC). ACTION: Notice of open..., National Oceanic and Atmospheric Administration. [FR Doc. 2011-27113 Filed 10-19-11; 8:45 am] BILLING CODE...

  10. Ocean-atmosphere interactions during cyclone Nargis

    Digital Repository Service at National Institute of Oceanography (India)

    Mc; Foltz, G.R.; Lee, T.; Murty, V.S.N.; Ravichandran, M.; Vecchi, G.A.; Vialard, J.; Wiggert, J.D.; Yu, L.

    =UTF-8 Author version: EOS: Trans. Am. Geophys. Union: 90(7); 2009; 53-60; doi:10.1029/2009EO070001 Ocean-Atmosphere Interactions During Cyclone Nargis M. J. McPhaden (1) , G. R. Foltz (2) , T. Lee (3) , V. S. N. Murty (4) , M... Moored Array for African-Asian-Australian Monsoon Analysis and Prediction; McPhaden et al, 2008) designed to complement a constellation of earth observing satellites for key environmental parameters such as winds, sea surface temperature (SST), and sea...

  11. Ocean-Atmosphere Interaction in Climate Changes

    Science.gov (United States)

    Liu, W. Timothy

    1999-01-01

    temperature anomalies with the cyclonic wind anomalies toward the coast. The results led to a new study which identifies decadal ocean variations in the Northeast Pacific. Three studies of oceanic responses to wind forcing caused by the seasonal change of monsoons, the passage of a typhoon, and the 1997 El Nino, were successfully conducted. Besides wind forcing, we continue to examine new techniques for estimating thermal and hydrologic fluxes, through the inverse ocean mixed-layer model, through divergence of atmospheric water transport, and by direct retrieval from radiances observed by microwave radiometers. Greenhouse warming has been linked to water vapor measured by two spaceborne sensors in two studies. In the first study, strong baroclinicity and deep convection were found to transport water vapor to the upper atmosphere and increase greenhouse trapping over the storm tracks of the North Pacific and Atlantic. In another study, the annual cycle of greenhouse warming were related to sea surface temperature (SST) and integrated water vapor, and the latitudinal dependence of the magnitudes and phases of the annual cycles were compared.

  12. The Met Office Coupled Atmosphere/Land/Ocean/Sea-Ice Data Assimilation System

    Science.gov (United States)

    Lea, Daniel; Mirouze, Isabelle; King, Robert; Martin, Matthew; Hines, Adrian

    2015-04-01

    The Met Office has developed a weakly-coupled data assimilation (DA) system using the global coupled model HadGEM3 (Hadley Centre Global Environment Model, version 3). At present the analysis from separate ocean and atmosphere DA systems are combined to produced coupled forecasts. The aim of coupled DA is to produce a more consistent analysis for coupled forecasts which may lead to less initialisation shock and improved forecast performance. The HadGEM3 coupled model combines the atmospheric model UM (Unified Model) at 60 km horizontal resolution on 85 vertical levels, the ocean model NEMO (Nucleus for European Modelling of the Ocean) at 25 km (at the equator) horizontal resolution on 75 vertical levels, and the sea-ice model CICE at the same resolution as NEMO. The atmosphere and the ocean/sea-ice fields are coupled every 1-hour using the OASIS coupler. The coupled model is corrected using two separate 6-hour window data assimilation systems: a 4D-Var for the atmosphere with associated soil moisture content nudging and snow analysis schemes on the one hand, and a 3D-Var FGAT for the ocean and sea-ice on the other hand. The background information in the DA systems comes from a previous 6-hour forecast of the coupled model. To isolate the impact of the coupled DA, 13-month experiments have been carried out, including 1) a full atmosphere/land/ocean/sea-ice coupled DA run, 2) an atmosphere-only run forced by OSTIA SSTs and sea-ice with atmosphere and land DA, and 3) an ocean-only run forced by atmospheric fields from run 2 with ocean and sea-ice DA. In addition, 5-day and 10-day forecast runs, have been produced from initial conditions generated by either run 1 or a combination of runs 2 and 3. The different results have been compared to each other and, whenever possible, to other references such as the Met Office atmosphere and ocean operational analyses or the OSTIA SST data. The performance of the coupled DA is similar to the existing separate ocean and atmosphere

  13. Impact on the earth, ocean and atmosphere

    Science.gov (United States)

    Ahrens, Thomas J.; O'Keefe, John D.

    1987-01-01

    On the basis of finite-difference techniques, cratering flow calculations are used to obtain the spatial attenuation of shock pressure with radius along the impact axis for the impact of silicate rock and iron impactors on a silicate half-space at speeds of 5 to 45 km/sec. Upon impact of a 10 to 30 km diameter silicate or water object onto a 5 km deep ocean overlying a silicate half-space planet at 30 km/sec, it is found that from 12 to 15 percent of the incident energy is coupled into the water. The mass of atmosphere lost due to impacts of 1 to 5 km radius projectiles is calculated.

  14. One kind of atmosphere-ocean three layer model for calculating the velocity of ocean current

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Z; Xi, P

    1979-10-01

    A three-layer atmosphere-ocean model is given in this paper to calcuate the velocity of ocean current, particularly the function of the vertical coordinate, taking into consideratiln (1) the atmospheric effect on the generation of ocean current, (2) a calculated coefficient of the eddy viscosity instead of an assumed one, and (3) the sea which actually varies in depth.

  15. Stochastic and Statistical Methods in Climate, Atmosphere, and Ocean Science

    NARCIS (Netherlands)

    D.T. Crommelin (Daan); B. Khouider; B. Engquist

    2015-01-01

    htmlabstractIntroduction The behavior of the atmosphere, oceans, and climate is intrinsically uncertain. The basic physical principles that govern atmospheric and oceanic flows are well known, for example, the Navier-Stokes equations for fluid flow, thermodynamic properties of moist air, and the

  16. The Martian Oasis Detector

    Science.gov (United States)

    Smith, P. H.; tomasko, M. G.; McEwen, A.; Rice, J.

    2000-07-01

    The next phase of unmanned Mars missions paves the way for astronauts to land on the surface of Mars. There are lessons to be learned from the unmanned precursor missions to the Moon and the Apollo lunar surface expeditions. These unmanned missions (Ranger, Lunar Orbiter, and Surveyor) provided the following valuable information, useful from both a scientific and engineering perspective, which was required to prepare the way for the manned exploration of the lunar surface: (1) high resolution imagery instrumental to Apollo landing site selection also tremendously advanced the state of Nearside and Farside regional geology; (2) demonstrated precision landing (less than two kilometers from target) and soft landing capability; (3) established that the surface had sufficient bearing strength to support a spacecraft; and (4) examination of the chemical composition and mechanical properties of the surface. The search for extinct or extant life on Mars will follow the water. However, geomorphic studies have shown that Mars has had liquid water on its surface throughout its geologic history. A cornucopia of potential landing sites with water histories (lakes, floodplains, oceans, deltas, hydrothermal regions) presently exist. How will we narrow down site selection and increase the likelihood of finding the signs of life? One way to do this is to identify 'Martian oases.' It is known that the Martian surface is often highly fractured and some areas have karst structures that support underground caves. Much of the water that formed the channels and valley networks is thought to be frozen underground. All that is needed to create the potential for liquid water is a near surface source of heat; recent lava flows and Martian meteorites attest to the potential for volcanic activity. If we can locate even one spot where fracturing, ice, and underground heat are co-located then we have the potential for an oasis. Such a discovery could truly excite the imaginations of both the

  17. Radiative transfer in atmosphere-sea ice-ocean system

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Z.; Stamnes, K.; Weeks, W.F. [Univ. of Alaska, Fairbanks, AK (United States); Tsay, S.C. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    1996-04-01

    Radiative energy is critical in controlling the heat and mass balance of sea ice, which significantly affects the polar climate. In the polar oceans, light transmission through the atmosphere and sea ice is essential to the growth of plankton and algae and, consequently, to the microbial community both in the ice and in the ocean. Therefore, the study of radiative transfer in the polar atmosphere, sea ice, and ocean system is of particular importance. Lacking a properly coupled radiative transfer model for the atmosphere-sea ice-ocean system, a consistent study of the radiative transfer in the polar atmosphere, snow, sea ice, and ocean system has not been undertaken before. The radiative transfer processes in the atmosphere and in the ice and ocean have been treated separately. Because the radiation processes in the atmosphere, sea ice, and ocean depend on each other, this separate treatment is inconsistent. To study the radiative interaction between the atmosphere, clouds, snow, sea ice, and ocean, a radiative transfer model with consistent treatment of radiation in the coupled system is needed and is under development.

  18. Coupled atmosphere-ocean models of Titan's past

    Science.gov (United States)

    Mckay, Christopher P.; Pollack, James B.; Lunine, Jonathan I.; Courtin, Regis

    1993-01-01

    The behavior and possible past evolution of fully coupled atmosphere and ocean model of Titan are investigated. It is found that Titan's surface temperature was about 20 K cooler at 4 Gyr ago and will be about 5 K warmer 0.5 Gyr in the future. The change in solar luminosity and the conversion of oceanic CH4 to C2H6 drive the evolution of the ocean and atmosphere over time. Titan appears to have experienced a frozen epoch about 3 Gyr ago independent of whether an ocean is present or not. This finding may have important implications for understanding the inventory of Titan's volatile compounds.

  19. Land-Ocean-Atmospheric Coupling Associated with Earthquakes

    Science.gov (United States)

    Prasad, A. K.; Singh, R. P.; Kumar, S.; Cervone, G.; Kafatos, M.; Zlotnicki, J.

    2007-12-01

    Earthquakes are well known to occur along the plate boundaries and also on the stable shield. The recent studies have shown existence of strong coupling between land-ocean-atmospheric parameters associated with the earthquakes. We have carried out detailed analysis of multi sensor data (optical and microwave remote) to show existence of strong coupling between land-ocean-atmospheric parameters associated with the earthquakes with focal depth up to 30 km and magnitude greater than 5.5. Complimentary nature of various land, ocean and atmospheric parameters will be demonstrated in getting an early warning information about an impending earthquake.

  20. Physical and meteorological data from the Tropical Atmosphere Ocean (TAO) array in the tropical Pacific Ocean

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Tropical Atmosphere Ocean (TAO) Array of 55 moored buoys spans the tropical Pacific from longitudes 165°E to 95°W between latitudes of approximately 8°S and...

  1. International Comprehensive Ocean-Atmosphere Data Set (ICOADS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface marine observational records from ships, buoys, and other platform types are processed and binned creating monthly global and regional grids of the...

  2. Comprehensive Ocean - Atmosphere Data Set (COADS) LMRF Arctic Subset

    Data.gov (United States)

    National Aeronautics and Space Administration — The Comprehensive Ocean - Atmosphere Data Set (COADS) LMRF Arctic subset contains marine surface weather reports for the region north of 65 degrees N from ships,...

  3. Glacial ocean circulation and stratification explained by reduced atmospheric temperature

    OpenAIRE

    Jansen, Malte F.

    2016-01-01

    To understand climatic swings between glacial and interglacial climates we need to explain the observed fluctuations in atmospheric carbon dioxide (CO2), which in turn are most likely driven by changes in the deep ocean circulation. This study presents a model for differences in the deep ocean circulation between glacial and interglacial climates consistent with both our physical understanding and various proxy observations. The results suggest that observed changes in ocean circulation and s...

  4. Ocean-atmosphere interaction and synoptic weather conditions in ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    turbances over oceans. On the other hand, these disturbances have an impact on the oceanic mixed layer, causing changes in the SST. This complex feed back process between the sea surface and the atmospheric disturbances is important in deter- mining the life span of the synoptic scale events. (Paul et al 1992). In view ...

  5. Impacts of atmospheric anthropogenic nitrogen on the open ocean

    NARCIS (Netherlands)

    Duce, R.A.; LaRoche, J.; Altieri, K.; Arrigo, K.R.; Baker, A.R.; Capone, D.G.; Cornell, S.; Dentener, F.; Galloway, J.; Ganeshram, R.S.; Geider, R.J.; Jickells, T.; Kuypers, M.M.; Langlois, R.; Liss, P.S.; Liu, S.; Middelburg, J.J.; Moore, C.M.; Nickovic, S.; Oschlies, A.; Pedersen, T.; Prospero, J.; Schlitzer, R.; Seitzinger, S.; Sorensen, L.L.; Uematsu, M.; Ulloa, O.; Voss, M.; Ward, B.; Zamora, L.

    2008-01-01

    Increasing quantities of atmospheric anthropogenic fixed nitrogen entering the open ocean could account for up to about a third of the ocean's external (nonrecycled) nitrogen supply and up to 3% of the annual new marine biological production, 0.3 petagram of carbon per year. This input could account

  6. Classroom Demonstrations Of Atmosphere-ocean Dynamics: Baroclinic Instability

    Science.gov (United States)

    Aurnou, Jonathan; Nadiga, B. T.

    2008-09-01

    Here we will present simple hands-on experimental demonstrations that show how baroclinic instabilities develop in rotating fluid dynamical systems. Such instabilities are found in the Earth's oceans and atmosphere as well as in the atmospheres and oceans of planetary bodies throughout the solar system and beyond. Our inexpensive experimental apparatus consists of a vinyl-record player, a wide shallow pan, and a weighted, dyed block of ice. Most directly, these demonstrations can be used to explain winter-time atmospheric weather patterns observed in Earth's mid-latitudes.

  7. Climate | National Oceanic and Atmospheric Administration

    Science.gov (United States)

    Jump to Content Enter Search Terms Weather Climate Oceans & Coasts Fisheries Satellites your local weather Enter your ZIP code GO Enter Search Terms Content OUR WORK Climate From to help people understand and prepare for climate variability and change. Climate. NOAA From

  8. Large-Scale Atmosphere-Ocean Coupling.

    Science.gov (United States)

    1984-05-01

    atmosphere (INT. -r, i 0) InEkman layer off the coast of Peru eastward) and meridional (y, positive north- the latter case. T, which was assumcd uniform...influence of teleconnectivity of the atmosphere is strongest for diabetic forcing located near the equatorial central Pacific, but much reduced i for ocinp...the monsoon diabetic heat sources during the latter half of the year (July- February, denoted by atching numerals). The extent of the diabetic beat

  9. Glacial ocean circulation and stratification explained by reduced atmospheric temperature.

    Science.gov (United States)

    Jansen, Malte F

    2017-01-03

    Earth's climate has undergone dramatic shifts between glacial and interglacial time periods, with high-latitude temperature changes on the order of 5-10 °C. These climatic shifts have been associated with major rearrangements in the deep ocean circulation and stratification, which have likely played an important role in the observed atmospheric carbon dioxide swings by affecting the partitioning of carbon between the atmosphere and the ocean. The mechanisms by which the deep ocean circulation changed, however, are still unclear and represent a major challenge to our understanding of glacial climates. This study shows that various inferred changes in the deep ocean circulation and stratification between glacial and interglacial climates can be interpreted as a direct consequence of atmospheric temperature differences. Colder atmospheric temperatures lead to increased sea ice cover and formation rate around Antarctica. The associated enhanced brine rejection leads to a strongly increased deep ocean stratification, consistent with high abyssal salinities inferred for the last glacial maximum. The increased stratification goes together with a weakening and shoaling of the interhemispheric overturning circulation, again consistent with proxy evidence for the last glacial. The shallower interhemispheric overturning circulation makes room for slowly moving water of Antarctic origin, which explains the observed middepth radiocarbon age maximum and may play an important role in ocean carbon storage.

  10. Ocean-Atmosphere Interactions Modulate Irrigation's Climate Impacts

    Science.gov (United States)

    Krakauer, Nir Y.; Puma, Michael J.; Cook, Benjamin I.; Gentine, Pierre; Nazarenko, Larissa

    2016-01-01

    Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean- atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity. We find that ocean-atmosphere interaction does impact the magnitude of global-mean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, particularly over the oceans, tend to be larger. The interaction amplifies irrigation-driven standing wave patterns in the tropics and mid-latitudes in our simulations, approximately doubling the global-mean amplitude of surface temperature changes due to irrigation. The fractions of global area experiencing significant annual-mean surface air temperature and precipitation change also approximately double with ocean-atmosphere interaction. Subject to confirmation with other models, these findings imply that LCLUC is an important contributor to climate change even in remote areas such as the Southern Ocean, and that attribution studies should include interactive oceans and need to consider LCLUC, including irrigation, as a truly global forcing that affects climate and the water cycle over ocean as well as land areas.

  11. Nudging atmosphere and ocean reanalyses for seasonal climate predictions

    Science.gov (United States)

    Piontek, Robert; Baehr, Johanna; Kornblueh, Luis; Müller, Wolfgang Alexander; Haak, Helmuth; Botzet, Michael; Matei, Daniela

    2010-05-01

    Seasonal climate forecasts based on state-of-the-art climate models have been developed recently. Here, we critically discuss the obstacles encountered in the setup of the ECHAM6/MPIOM global coupled climate model to perform climate predictions on seasonal to decadal time scales. We particularly focus on the initialization procedure, especially on the implementation of the nudging scheme, in which different reanalysis products are used in the atmosphere (e.g.ERA40), and the ocean (e.g., GECCO). Nudging in the atmosphere appears to be sensitive to the following choices: limiting the spectral range of nudging, whether or not temperature is nudged, the strength of the nudging coefficient for surface pressure, and the height at which the planetary boundary layer is excluded from nudging. We find that including nudging in both the atmosphere and the ocean gives improved results over nudging only the ocean or the atmosphere. For the implementation of the nudging in the atmosphere, we find the most significant improvements in the solution when either the planetary boundary layer is excluded, or if nudging of temperature is omitted. There are significant improvements in the solution when resolution is increased in both the atmosphere and in the ocean. Our tests form the basis for the prediction system introduced in the abstract of Müller et al., where hindcasts are analysed as well.

  12. Southern hemisphere ocean CO2 uptake: reconciling atmospheric and oceanic estimates

    International Nuclear Information System (INIS)

    Roy, T.; Matear, R.; Rayner, P.; Francey, R.

    2003-01-01

    Using an atmospheric inversion model we investigate the southern hemisphere ocean CO 2 uptake. From sensitivity studies that varied both the initial ocean flux distribution and the atmospheric data used in the inversion, our inversion predicted a total (ocean and land) uptake of 1.65-1.90 Gt C/yr. We assess the consistency between the mean southern hemisphere ocean uptake predicted by an atmospheric inversion model for the 1991-1997 period and the T99 ocean flux estimate based on observed pCO 2 in Takahashi et al. (2002; Deep-Sea Res II, 49, 1601-1622). The inversion can not match the large 1.8 Gt C/yr southern extratropical (20-90 deg S) uptake of the T99 ocean flux estimate without producing either unreasonable land fluxes in the southern mid-latitudes or by increasing the mismatches between observed and simulated atmospheric CO 2 data. The southern extratropical uptake is redistributed between the mid and high latitudes. Our results suggest that the T99 estimate of the Southern Ocean uptake south of 50 deg S is too large, and that the discrepancy reflects the inadequate representation of wintertime conditions in the T99 estimate

  13. Atmospheric and oceanic dust fluxes in the northeastern tropical Atlantic Ocean: how close a coupling?

    Directory of Open Access Journals (Sweden)

    A. Bory

    2002-12-01

    Full Text Available Atmospheric inputs to the ocean of dust originating from Africa are compared with downward dust flux in the oceanic water column. Atmospheric fluxes were estimated using remote-sensing-derived dust optical thickness and parameters from a transport/deposition model (TM2z. Oceanic fluxes were measured directly over/in two regions of contrasting primary productivity of the northeastern tropical Atlantic (one mesotrophic and one oligotrophic, located at about 500 and 1500 km off Mauritania underlying the offshore dust plume. In both regions, estimates of annual atmospheric dust inputs to the ocean surface are lower than, but of the same order of magnitude as, oceanic fluxes (49.5 and 8.8 mg.m-2 .d-1 in the mesotrophic and oligotrophic regions. Part of this mismatch may reflect both a general flaw in the dust grain size distribution used in transport models, which likely underestimates large particles, and/or lateral advection to each region of dustier surface waters from upstream, where dust deposition is higher. Higher-frequency temporal coupling between atmospheric and oceanic fluxes seems to be primary-productivity dependent, as hypothesized in previously reported studies.Key words. Atmospheric composition and structure (aerosols and particles; geochemical cycles Oceanography: biological and chemical (geochemistry

  14. Oceanic Emissions and Atmospheric Depositions of Volatile Organic Compounds

    Science.gov (United States)

    Yang, M.; Blomquist, B.; Beale, R.; Nightingale, P. D.; Liss, P. S.

    2015-12-01

    Atmospheric volatile organic compounds (VOCs) affect the tropospheric oxidative capacity due to their ubiquitous abundance and relatively high reactivity towards the hydroxyal radical. Over the ocean and away from terrestrial emission sources, oxygenated volatile organic compounds (OVOCs) make up a large fraction of VOCs as airmasses age and become more oxidized. In addition to being produced or destroyed in the marine atmosphere, OVOCs can also be emitted from or deposited to the surface ocean. Here we first present direct air-sea flux measurements of three of the most abundant OVOCs - methanol, acetone, and acetaldehyde, by the eddy covariance technique from two cruises in the Atlantic: the Atlantic Meridional Transect in 2012 and the High Wind Gas Exchange Study in 2013. The OVOC mixing ratios were quantified by a high resolution proton-reaction-transfer mass spectrometer with isotopically labeled standards and their air-sea (net) fluxes were derived from the eddy covariance technique. Net methanol flux was consistently from the atmosphere to the surface ocean, while acetone varied from supersaturation (emission) in the subtropics to undersaturation (deposition) in the higher latitudes of the North Atlantic. The net air-sea flux of acetaldehyde is near zero through out the Atlantic despite the apparent supersaturation of this compound in the surface ocean. Knowing the dissolved concentrations and in situ production rates of these compounds in seawater, we then estimate their bulk atmospheric depositions and oceanic emissions. Lastly, we summarize the state of knowledge on the air-sea transport of a number of organic gasses, and postulate the magnitude and environmental impact of total organic carbon transfer between the ocean and the atmosphere.

  15. Instabilities in the coupled equatorial ocean atmosphere system

    NARCIS (Netherlands)

    Dijkstra, H.A.; Vaart, P.C.F. van der

    1999-01-01

    The large-scale interaction between the ocean and atmosphere is one of the impor- tant factors of natural climate variability.The El-Niño/Southern Oscillation (ENSO) phenomenon in the Tropical Pacific is one of the most prominent examples of climate variability on interannual time scales.ENSO has

  16. Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere

    Science.gov (United States)

    Boyd, Philip W.

    The ocean is a major sink for both preindustrial and anthropogenic carbon dioxide. Both physically and biogeochemically driven pumps, termed the solubility and biological pump, respectively Fig.5.1) are responsible for the majority of carbon sequestration in the ocean's interior [1]. The solubility pump relies on ocean circulation - specifically the impact of cooling of the upper ocean at high latitudes both enhances the solubility of carbon dioxide and the density of the waters which sink to great depth (the so-called deepwater formation) and thereby sequester carbon in the form of dissolved inorganic carbon (Fig.5.1). The biological pump is driven by the availability of preformed plant macronutrients such as nitrate or phosphate which are taken up by phytoplankton during photosynthetic carbon fixation. A small but significant proportion of this fixed carbon sinks into the ocean's interior in the form of settling particles, and in order to maintain equilibrium carbon dioxide from the atmosphere is transferred across the air-sea interface into the ocean (the so-called carbon drawdown) thereby decreasing atmospheric carbon dioxide (Fig.5.1).Fig.5.1

  17. Preface "Nonlinear processes in oceanic and atmospheric flows"

    Directory of Open Access Journals (Sweden)

    E. García-Ladona

    2010-05-01

    Full Text Available Nonlinear phenomena are essential ingredients in many oceanic and atmospheric processes, and successful understanding of them benefits from multidisciplinary collaboration between oceanographers, meteorologists, physicists and mathematicians. The present Special Issue on "Nonlinear Processes in Oceanic and Atmospheric Flows" contains selected contributions from attendants to the workshop which, in the above spirit, was held in Castro Urdiales, Spain, in July 2008. Here we summarize the Special Issue contributions, which include papers on the characterization of ocean transport in the Lagrangian and in the Eulerian frameworks, generation and variability of jets and waves, interactions of fluid flow with plankton dynamics or heavy drops, scaling in meteorological fields, and statistical properties of El Niño Southern Oscillation.

  18. New constraints on terrestrial and oceanic sources of atmospheric methanol

    Directory of Open Access Journals (Sweden)

    D. B. Millet

    2008-12-01

    Full Text Available We use a global 3-D chemical transport model (GEOS-Chem to interpret new aircraft, surface, and oceanic observations of methanol in terms of the constraints that they place on the atmospheric methanol budget. Recent measurements of methanol concentrations in the ocean mixed layer (OML imply that in situ biological production must be the main methanol source in the OML, dominating over uptake from the atmosphere. It follows that oceanic emission and uptake must be viewed as independent terms in the atmospheric methanol budget. We deduce that the marine biosphere is a large primary source (85 Tg a−1 of methanol to the atmosphere and is also a large sink (101 Tg a−1, comparable in magnitude to atmospheric oxidation by OH (88 Tg a−1. The resulting atmospheric lifetime of methanol in the model is 4.7 days. Aircraft measurements in the North American boundary layer imply that terrestrial plants are a much weaker source than presently thought, likely reflecting an overestimate of broadleaf tree emissions, and this is also generally consistent with surface measurements. We deduce a terrestrial plant source of 80 Tg a−1, comparable in magnitude to the ocean source. The aircraft measurements show a strong correlation with CO (R2=0.51−0.61 over North America during summer. We reproduce this correlation and slope in the model with the reduced plant source, which also confirms that the anthropogenic source of methanol must be small. Our reduced plant source also provides a better simulation of methanol observations over tropical South America.

  19. Coherent Multidecadal Atmospheric and Oceanic Variability in the North Atlantic: Blocking Corresponds with Warm Subpolar Ocean

    Science.gov (United States)

    Hakkinen, Sirpa M.; Rhines, P. B.; Worthen, D. L.

    2012-01-01

    Winters with frequent atmospheric blocking, in a band of latitudes from Greenland to Western Europe, are found to persist over several decades and correspond to a warm North Atlantic Ocean. This is evident in atmospheric reanalysis data, both modern and for the full 20th century. Blocking is approximately in phase with Atlantic multidecadal ocean variability (AMV). Wintertime atmospheric blocking involves a highly distorted jetstream, isolating large regions of air from the westerly circulation. It influences the ocean through windstress-curl and associated air/sea heat flux. While blocking is a relatively high-frequency phenomenon, it is strongly modulated over decadal timescales. The blocked regime (weaker ocean gyres, weaker air-sea heat flux, paradoxically increased transport of warm subtropical waters poleward) contributes to the warm phase of AMV. Atmospheric blocking better describes the early 20thC warming and 1996-2010 warm period than does the NAO index. It has roots in the hemispheric circulation and jet stream dynamics. Subpolar Atlantic variability covaries with distant AMOC fields: both these connections may express the global influence of the subpolar North Atlantic ocean on the global climate system.

  20. Atmospheric deposition of methanol over the Atlantic Ocean

    Science.gov (United States)

    Yang, Mingxi; Nightingale, Philip D.; Beale, Rachael; Liss, Peter S.; Blomquist, Byron; Fairall, Christopher

    2013-01-01

    In the troposphere, methanol (CH3OH) is present ubiquitously and second in abundance among organic gases after methane. In the surface ocean, methanol represents a supply of energy and carbon for marine microbes. Here we report direct measurements of air–sea methanol transfer along a ∼10,000-km north–south transect of the Atlantic. The flux of methanol was consistently from the atmosphere to the ocean. Constrained by the aerodynamic limit and measured rate of air–sea sensible heat exchange, methanol transfer resembles a one-way depositional process, which suggests dissolved methanol concentrations near the water surface that are lower than what were measured at ∼5 m depth, for reasons currently unknown. We estimate the global oceanic uptake of methanol and examine the lifetimes of this compound in the lower atmosphere and upper ocean with respect to gas exchange. We also constrain the molecular diffusional resistance above the ocean surface—an important term for improving air–sea gas exchange models. PMID:24277830

  1. Atmosphere-ocean feedbacks in a coastal upwelling system

    Science.gov (United States)

    Alves, J. M. R.; Peliz, A.; Caldeira, R. M. A.; Miranda, P. M. A.

    2018-03-01

    The COAWST (Coupled Ocean-Atmosphere-Wave-Sediment Transport) modelling system is used in different configurations to simulate the Iberian upwelling during the 2012 summer, aiming to assess the atmosphere-ocean feedbacks in the upwelling dynamics. When model results are compared with satellite measurements and in-situ data, two-way coupling is found to have a moderate impact in data-model statistics. A significant reinforcement of atmosphere-ocean coupling coefficients is, however, observed in the two-way coupled run, and in the WRF and ROMS runs forced by previously simulated SST and wind fields, respectively. The increasing in the coupling coefficient is associated with slight, but potentially important changes in the low-level coastal jet in the atmospheric marine boundary layer. While these results do not imply the need for fully coupled simulations in many applications, they show that in seasonal numerical studies such simulations do not degrade the overall model performance, and contribute to produce better dynamical fields.

  2. Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

    International Nuclear Information System (INIS)

    Washington, W.M.; Meehl, G.A.

    1990-01-01

    The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming

  3. Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

    International Nuclear Information System (INIS)

    Washington, W.M.; Meehl, G.A.

    1991-01-01

    The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming. 46 refs.; 20 figs.; 1 tab

  4. Ocean-atmosphere coupled climate model development at SAWS: description and diagnosis

    CSIR Research Space (South Africa)

    Beraki, A

    2011-09-01

    Full Text Available This paper introduces the South African Weather Service's coupled ocean-atmosphere model. The paper also demonstrates the advances made in configuring an operational coupled ocean-atmosphere model in South Africa for seasonal forecast production...

  5. International Comprehensive Ocean Atmosphere Data Set (ICOADS) in Near-Real Time (NRT)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) Near-Real-Time (NRT) product is an extension of the official ICOADS dataset with preliminary...

  6. International Comprehensive Ocean-Atmosphere Data Set (ICOADS) with Enhanced Trimming, Release 3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains the latest official release of International Comprehensive Ocean-Atmosphere Data Set (ICOADS) with Enhanced Trimming, provided in a common...

  7. International Comprehensive Ocean-Atmosphere Data Set (ICOADS) Release 3.0 - Monthly Summary Groups (MSG)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset, the International Comprehensive Ocean-Atmosphere Data Set (ICOADS), is the most widely-used freely available collection of surface marine observations,...

  8. International Comprehensive Ocean Atmosphere Data Set (ICOADS) And NCEI Global Marine Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — International Comprehensive Ocean Atmosphere Data Set (ICOADS) consists of digital data set DSI-1173, archived at the National Center for Environmental Information...

  9. Effects of atmospheric inorganic nitrogen deposition on ocean biogeochemistry

    OpenAIRE

    Krishnamurthy, Aparna; Moore, J. Keith; Zender, Charles S; Luo, Chao

    2007-01-01

     We perform a sensitivity study with the Biogeochemical Elemental Cycling (BEC) ocean model to understand the impact of atmospheric inorganic nitrogen deposition on marine biogeochemistry and air-sea CO2 exchange. Simulations involved examining the response to three different atmospheric inorganic nitrogen deposition scenarios namely, Pre-industrial (22 Tg N/year), 1990s (39 Tg N/year), and an Intergovernmental Panel on Climate Change (IPCC) prediction for 2100, IPCC-A1FI (69 Tg N/year). Glob...

  10. Entropy budget of the earth,atmosphere and ocean system

    Institute of Scientific and Technical Information of China (English)

    GAN Zijun; YAN Youfangand; QI Yiquan

    2004-01-01

    The energy budget in the system of the earth, atmosphere and ocean conforms to the first law of thermodynamics, namely the law of conservation of energy, and it is balanced when the system is in a steady-state condition. However, the entropy budget following the second law of thermodynamics is unbalanced. In this paper, we deduce the expressions of entropy flux and re-estimate the earth, atmosphere and ocean annual mean entropy budget with the updated climatologically global mean energy budget and the climatologically air-sea flux data. The calculated results show that the earth system obtains a net influx of negative entropy (-1179.3 mWm-2K-1) from its surroundings, and the atmosphere and the ocean systems obtain a net input of negative entropy at about -537.4 mWm-2K-1 and -555.6 mWm-2K-1, respectively. Calculations of the entropy budget can provide some guidance for further understanding the spatial-temporal change of the local entropy flux, and the entropy production resulting from all kinds of irreversible processes inside these systems.

  11. Medicanes in an ocean-atmosphere coupled regional climate model

    Science.gov (United States)

    Akhtar, N.; Brauch, J.; Dobler, A.; Béranger, K.; Ahrens, B.

    2014-08-01

    So-called medicanes (Mediterranean hurricanes) are meso-scale, marine, and warm-core Mediterranean cyclones that exhibit some similarities to tropical cyclones. The strong cyclonic winds associated with medicanes threaten the highly populated coastal areas around the Mediterranean basin. To reduce the risk of casualties and overall negative impacts, it is important to improve the understanding of medicanes with the use of numerical models. In this study, we employ an atmospheric limited-area model (COSMO-CLM) coupled with a one-dimensional ocean model (1-D NEMO-MED12) to simulate medicanes. The aim of this study is to assess the robustness of the coupled model in simulating these extreme events. For this purpose, 11 historical medicane events are simulated using the atmosphere-only model, COSMO-CLM, and coupled model, with different setups (horizontal atmospheric grid spacings of 0.44, 0.22, and 0.08°; with/without spectral nudging, and an ocean grid spacing of 1/12°). The results show that at high resolution, the coupled model is able to not only simulate most of medicane events but also improve the track length, core temperature, and wind speed of simulated medicanes compared to the atmosphere-only simulations. The results suggest that the coupled model is more proficient for systemic and detailed studies of historical medicane events, and that this model can be an effective tool for future projections.

  12. Coupling atmospheric and ocean wave models for storm simulation

    DEFF Research Database (Denmark)

    Du, Jianting

    the atmosphere must, by conservation, result in the generation of the surface waves and currents. The physics-based methods are sensitive to the choice of wind-input source function (Sin), parameterization of high-frequency wave spectra tail, and numerical cut-off frequencies. Unfortunately, literature survey......This thesis studies the wind-wave interactions through the coupling between the atmospheric model and ocean surface wave models. Special attention is put on storm simulations in the North Sea for wind energy applications in the coastal zones. The two aspects, namely storm conditions and coastal...... shows that in most wind-wave coupling systems, either the Sin in the wave model is different from the one used for the momentum flux estimation in the atmospheric model, or the methods are too sensitive to the parameterization of high-frequency spectra tail and numerical cut-off frequencies. To confront...

  13. OASIS User Manual

    CERN Document Server

    Bojtar, L

    2009-01-01

    The OASIS system has been operational for years now. After a long development the project has reached a state where the number of features it provides exceeds largely what most of its users knows about. The author felt it was time to write a user manual explaining all the functionality of the viewer application. This document is a user manual, concentrating on the functionality of the viewer from the user’s point of view. There are already documents available on the project’s web site about the technical aspects at http://project-oasis.web.cern.ch/project-oasis/presentations.htm . There was an attempt to produce a tutorial on the viewer, but it didn’t get much further than the table of contents, that however is well thought. The structure of this user manual follows the same principle, the basic and most often used features are grouped together. Advanced or less often used features are described in a separate chapter. There is a second organizational principle, features belong to different levels: chann...

  14. Impacts of inhomogeneous landscapes in oasis interior on the oasis self-maintenance mechanism by integrating numerical model with satellite data

    Directory of Open Access Journals (Sweden)

    X. Meng

    2012-10-01

    Full Text Available The impacts of inhomogeneity of the oasis interior on the oasis self-maintenance mechanism are investigated by using the mesoscale model MM5 (the fifth-generation Pennsylvania State University National Center for Atmospheric Research (NCAR mesoscale model with satellite observations of land use types, vegetation fraction and surface-layer soil moisture from MODIS (Moderate Resolution Imaging Spectroradiometer data. Four simulations were performed, among which the CTL (control simulation and MOD (moderated simulation with parameters replaced by MODIS data were used to validate the model results; EXP1 (experiment 1 and EXP2 (experiment 2 were designed to study the inhomogeneity of oasis interior. Results show that the changes of oasis heterogeneity influence the surface heat-flux partitioning, which leads to a larger "cold-wet" effect over the oasis. Vertical sections of humidity illustrate the existence of a moisture-inversion level, and the deeper moisture inversion of EXP1 and EXP2 further indicates that the relative homogeneity in the oasis interior helps produce stronger humidity inversion over the oasis, thus limiting evaporation. This is further verified by the analysis of the secondary circulation, which shows that the more homogeneous land surface conditions lead to stronger secondary circulation and less turbulent drafts over the oasis interior, playing a positive role in the oasis self-maintenance and development.

  15. Indian Ocean and Indian summer monsoon: relationships without ENSO in ocean-atmosphere coupled simulations

    Science.gov (United States)

    Crétat, Julien; Terray, Pascal; Masson, Sébastien; Sooraj, K. P.; Roxy, Mathew Koll

    2017-08-01

    The relationship between the Indian Ocean and the Indian summer monsoon (ISM) and their respective influence over the Indo-Western North Pacific (WNP) region are examined in the absence of El Niño Southern Oscillation (ENSO) in two partially decoupled global experiments. ENSO is removed by nudging the tropical Pacific simulated sea surface temperature (SST) toward SST climatology from either observations or a fully coupled control run. The control reasonably captures the observed relationships between ENSO, ISM and the Indian Ocean Dipole (IOD). Despite weaker amplitude, IODs do exist in the absence of ENSO and are triggered by a boreal spring ocean-atmosphere coupled mode over the South-East Indian Ocean similar to that found in the presence of ENSO. These pure IODs significantly affect the tropical Indian Ocean throughout boreal summer, inducing a significant modulation of both the local Walker and Hadley cells. This meridional circulation is masked in the presence of ENSO. However, these pure IODs do not significantly influence the Indian subcontinent rainfall despite overestimated SST variability in the eastern equatorial Indian Ocean compared to observations. On the other hand, they promote a late summer cross-equatorial quadrupole rainfall pattern linking the tropical Indian Ocean with the WNP, inducing important zonal shifts of the Walker circulation despite the absence of ENSO. Surprisingly, the interannual ISM rainfall variability is barely modified and the Indian Ocean does not force the monsoon circulation when ENSO is removed. On the contrary, the monsoon circulation significantly forces the Arabian Sea and Bay of Bengal SSTs, while its connection with the western tropical Indian Ocean is clearly driven by ENSO in our numerical framework. Convection and diabatic heating associated with above-normal ISM induce a strong response over the WNP, even in the absence of ENSO, favoring moisture convergence over India.

  16. Decadal atmosphere-ocean variations in the Pacific

    Science.gov (United States)

    Trenberth, Kevin E.; Hurrell, James W.

    1994-03-01

    Considerable evidence has emerged of a substantial decade-long change in the north Pacific atmosphere and ocean lasting from about 1976 to 1988. Observed significant changes in the atmospheric circulation throughout the troposphere revealed a deeper and eastward shifted Aleutian low pressure system in the winter half year which advected warmer and moister air along the west coast of North America and into Alaska and colder air over the north Pacific. Consequently, there were increases in temperatures and sea surface temperatures (SSTs) along the west coast of North America and Alaska but decreases in SSTs over the central north Pacific, as well as changes in coastal rainfall and streamflow, and decreases in sea ice in the Bering Sea. Associated changes occurred in the surface wind stress, and, by inference, in the Sverdrup transport in the north Pacific Ocean. Changes in the monthly mean flow were accompanied by a southward shift in the storm tracks and associated synoptic eddy activity and in the surface ocean sensible and latent heat fluxes. In addition to the changes in the physical environment, the deeper Aleutian low increased the nutrient supply as seen through increases in total chlorophyll in the water column, phytoplankton and zooplankton. These changes, along with the altered ocean currents and temperatures, changed the migration patterns and increased the stock of many fish species. A north Pacific (NP) index is defined to measure the decadal variations, and the temporal variability of the index is explored on daily, annual, interannual and decadal time scales. The dominant atmosphere-ocean relation in the north Pacific is one where atmospheric changes lead SSTs by one to two months. However, strong ties are revealed with events in the tropical Pacific, with changes in tropical Pacific SSTs leading SSTs in the north Pacific by three months. Changes in the storm tracks in the north Pacific help to reinforce and maintain the anomalous circulation in the

  17. Evolving Oxygen Landscape of the Early Atmosphere and Oceans

    Science.gov (United States)

    Lyons, T. W.; Reinhard, C. T.; Planavsky, N. J.

    2013-12-01

    The past decade has witnessed remarkable advances in our understanding of oxygen on the early Earth, and a new framework, the topic of this presentation, is now in place to address the controls on spatiotemporal distributions of oxygen and their potential relationships to deep-Earth processes. Recent challenges to the Archean biomarker record have put an added burden on inorganic geochemistry to fingerprint and quantify the early production, accumulation, and variation of biospheric oxygen. Fortunately, a wide variety of techniques now point convincingly to photosynthetic oxygen production and dynamic accumulation well before the canonical Great Oxidation Event (GOE). Recent modeling of sulfur recycling over this interval allows for transient oxygen accumulation in the atmosphere without the disappearance of non-mass-dependent (NMD) sulfur isotope anomalies from the stratigraphic record and further allows for persistent accumulation in the atmosphere well before the permanent disappearance of NMD signals. This recent work suggests that the initial rise of oxygen may have occurred in fits and starts rather than a single step, and that once permanently present in the atmosphere, oxygen likely rose to high levels and then plummeted, in phase with the Paleoproterozoic Lomagundi positive carbon isotope excursion. More than a billion years of oxygen-free conditions in the deep ocean followed and set a challenging course for life, including limited abundances and diversity of eukaryotic organisms. Despite this widespread anoxia, sulfidic (euxinic) conditions were likely limited to productive ocean margins. Nevertheless, euxinia was sufficiently widespread to impact redox-dependent nutrient relationships, particularly the availability of bioessential trace metals critical in the nitrogen cycle, which spawned feedbacks that likely maintained oxygen at very low levels in the ocean and atmosphere and delayed the arrival of animals. Then, in the mid, pre-glacial Neoproterozoic

  18. South African seasonal rainfall prediction performance by a coupled ocean-atmosphere model

    CSIR Research Space (South Africa)

    Landman, WA

    2010-12-01

    Full Text Available Evidence is presented that coupled ocean-atmosphere models can already outscore computationally less expensive atmospheric models. However, if the atmospheric models are forced with highly skillful SST predictions, they may still be a very strong...

  19. Estimation of the Atmosphere-Ocean Fluxes of Greenhouse Gases and Aerosols at the Finer Resolution of the Coastal Ocean

    Czech Academy of Sciences Publication Activity Database

    Vieira, V.; Sahlée, E.; Juruš, Pavel; Clementi, E.; Pettersson, H.; Mateus, M.

    2016-01-01

    Roč. 18 (2016), EGU2016-1990-1 ISSN 1607-7962. [EGU General Assembly 2016. 17.04.2016-22.04.2016, Vienna] Institutional support: RVO:67985807 Keywords : greenhouse gases * carbon cycle * atmosphere- ocean interaction * atmosphere modelling * ocean modelling Subject RIV: DG - Athmosphere Sciences, Meteorology

  20. Introduction to PDEs and waves for the atmosphere and ocean

    CERN Document Server

    Majda, Andrew

    2003-01-01

    The goals of these lecture notes, based on courses presented by the author at the Courant Institute of Mathematical Sciences, are to introduce mathematicians to the fascinating and important area of atmosphere/ocean science (AOS) and, conversely, to develop a mathematical viewpoint on basic topics in AOS of interest to the disciplinary AOS community, ranging from graduate students to researchers. The lecture notes emphasize the serendipitous connections between applied mathematics and geophysical flows in the style of modern applied mathematics, where rigorous mathematical analysis as well as

  1. Tropical teleconnections via the ocean and atmosphere induced by Southern Ocean deep convective events

    Science.gov (United States)

    Marinov, I.; Cabre, A.; Gunn, A.; Gnanadesikan, A.

    2016-12-01

    The current generation (CMIP5) of Earth System Models (ESMs) shows a huge variability in their ability to represent Southern Ocean (SO) deep-ocean convection and Antarctic Bottom Water, with a preference for open-sea convection in the Weddell and Ross gyres. A long control simulation in a coarse 3o resolution ESM (the GFDL CM2Mc model) shows a highly regular multi-decadal oscillation between periods of SO open sea convection and non-convective periods. This process also happens naturally, with different frequencies and durations of convection across most CMIP5 models under preindustrial forcing (deLavergne et al, 2014). Here we assess the impact of SO deep convection and resulting sea surface temperature (SST) anomalies on the tropical atmosphere and ocean via teleconnections, with a focus on interannual to multi-decadal timescales. We combine analysis of our low-resolution coupled model with inter-model analysis across historical CMIP5 simulations. SST cooling south of 60S during non-convective decades triggers a stronger, northward shifted SH Hadley cell, which results in intensified northward cross-equatorial moist heat transport and a poleward shift in the ITCZ. Resulting correlations between the cross-equatorial atmospheric heat transport and ITCZ location are in good agreement with recent theories (e.g. Frierson et al. 2013; Donohoe et al. 2014). Lagged correlations between a SO convective index and cross-equatorial heat transports (in the atmosphere and ocean), as well as various tropical (and ENSO) climate indices are analyzed. In the ocean realm, we find that non-convective decades result in weaker AABW formation and weaker ACC but stronger Antarctic Intermediate Water (AAIW) formation, likely as a result of stronger SO westerlies (more positive SAM). The signals of AABW and AAIW are seen in the tropics on short timescales of years to decades in the temperature, heat storage and heat transport anomalies and also in deep and intermediate ocean oxygen. Most

  2. Radiative transfer through terrestrial atmosphere and ocean: Software package SCIATRAN

    International Nuclear Information System (INIS)

    Rozanov, V.V.; Rozanov, A.V.; Kokhanovsky, A.A.; Burrows, J.P.

    2014-01-01

    SCIATRAN is a comprehensive software package for the modeling of radiative transfer processes in the terrestrial atmosphere and ocean in the spectral range from the ultraviolet to the thermal infrared (0.18–40μm) including multiple scattering processes, polarization, thermal emission and ocean–atmosphere coupling. The software is capable of modeling spectral and angular distributions of the intensity or the Stokes vector of the transmitted, scattered, reflected, and emitted radiation assuming either a plane-parallel or a spherical atmosphere. Simulations are done either in the scalar or in the vector mode (i.e. accounting for the polarization) for observations by space-, air-, ship- and balloon-borne, ground-based, and underwater instruments in various viewing geometries (nadir, off-nadir, limb, occultation, zenith-sky, off-axis). All significant radiative transfer processes are accounted for. These are, e.g. the Rayleigh scattering, scattering by aerosol and cloud particles, absorption by gaseous components, and bidirectional reflection by an underlying surface including Fresnel reflection from a flat or roughened ocean surface. The software package contains several radiative transfer solvers including finite difference and discrete-ordinate techniques, an extensive database, and a specific module for solving inverse problems. In contrast to many other radiative transfer codes, SCIATRAN incorporates an efficient approach to calculate the so-called Jacobians, i.e. derivatives of the intensity with respect to various atmospheric and surface parameters. In this paper we discuss numerical methods used in SCIATRAN to solve the scalar and vector radiative transfer equation, describe databases of atmospheric, oceanic, and surface parameters incorporated in SCIATRAN, and demonstrate how to solve some selected radiative transfer problems using the SCIATRAN package. During the last decades, a lot of studies have been published demonstrating that SCIATRAN is a valuable

  3. Model coupler for coupling of atmospheric, oceanic, and terrestrial models

    International Nuclear Information System (INIS)

    Nagai, Haruyasu; Kobayashi, Takuya; Tsuduki, Katsunori; Kim, Keyong-Ok

    2007-02-01

    A numerical simulation system SPEEDI-MP, which is applicable for various environmental studies, consists of dynamical models and material transport models for the atmospheric, terrestrial, and oceanic environments, meteorological and geographical databases for model inputs, and system utilities for file management, visualization, analysis, etc., using graphical user interfaces (GUIs). As a numerical simulation tool, a model coupling program (model coupler) has been developed. It controls parallel calculations of several models and data exchanges among them to realize the dynamical coupling of the models. It is applicable for any models with three-dimensional structured grid system, which is used by most environmental and hydrodynamic models. A coupled model system for water circulation has been constructed with atmosphere, ocean, wave, hydrology, and land-surface models using the model coupler. Performance tests of the coupled model system for water circulation were also carried out for the flood event at Saudi Arabia in January 2005 and the storm surge case by the hurricane KATRINA in August 2005. (author)

  4. Atmospheric Concentrations of Persistent Organic Pollutants in the Southern Ocean

    Science.gov (United States)

    Vlahos, P.; Edson, J.; Cifuentes, A.; McGillis, W. R.; Zappa, C.

    2008-12-01

    Long-range transport of persistent organic pollutant (POPs) is a global concern. Remote regions such as the Southern Ocean are greatly under-sampled though critical components in understanding POPs cycling. Over 20 high-volume air samples were collected in the Southern Ocean aboard the RV Brown during the GASEX III experiment between Mar 05 to April 9 2008. The relatively stationary platform (51S,38W) enabled the collection of a unique atmospheric time series at this open ocean station. Air sampling was also conducted across transects from Punto Arenas, Chile and to Montevideo, Uruguay. Samples were collected using glass sleeves packed with poly-urethane foam plugs and C-18 resin in order to collect target organic pollutants (per-fluorinated compounds, currently and historically used pesticides) in this under-sampled region. Here we present POPs concentrations and trends over the sampled period and compare variations with air parcel back trajectories to establish potential origins of their long-range transport.

  5. Atmosphere-surface interactions over polar oceans and heterogeneous surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Vihma, T.

    1995-12-31

    Processes of interaction between the atmospheric boundary layer and the planetary surface have been studied with special emphasis on polar ocean surfaces: the open ocean, leads, polynyas and sea ice. The local exchange of momentum, heat and moisture has been studied experimentally both in the Weddell Sea and in the Greenland Sea. Exchange processes over heterogeneous surfaces are addressed by modelling studies. Over a homogeneous surface, the local turbulent fluxes can be reasonably well estimated using an iterative flux-profile scheme based on the Monin-Obukhov similarity theory. In the Greenland Sea, the near-surface air temperature and the generally small turbulent fluxes over the open ocean were affected by the sea surface temperature fronts. Over the sea ice cover in the Weddell Sea, the turbulent sensible heat flux was generally downwards, and together with an upward oceanic heat flux through the ice it compensated the heat loss from the surface via long-wave radiation. The wind dominated on time scales of days, while the current became important on longer time scales. The drift dynamics showed apparent spatial differences between the eastern and western regions, as well as between the Antarctic Circumpolar Current and the rest of the Weddell Sea. Inertial motion was present in regions of low ice concentration. The surface heterogeneity, arising e.g. from roughness or temperature distribution, poses a problem for the parameterization of surface exchange processes in large-scale models. In the case of neutral flow over a heterogeneous terrain, an effective roughness length can be used to parameterize the roughness effects

  6. Atmosphere-surface interactions over polar oceans and heterogeneous surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Vihma, T

    1996-12-31

    Processes of interaction between the atmospheric boundary layer and the planetary surface have been studied with special emphasis on polar ocean surfaces: the open ocean, leads, polynyas and sea ice. The local exchange of momentum, heat and moisture has been studied experimentally both in the Weddell Sea and in the Greenland Sea. Exchange processes over heterogeneous surfaces are addressed by modelling studies. Over a homogeneous surface, the local turbulent fluxes can be reasonably well estimated using an iterative flux-profile scheme based on the Monin-Obukhov similarity theory. In the Greenland Sea, the near-surface air temperature and the generally small turbulent fluxes over the open ocean were affected by the sea surface temperature fronts. Over the sea ice cover in the Weddell Sea, the turbulent sensible heat flux was generally downwards, and together with an upward oceanic heat flux through the ice it compensated the heat loss from the surface via long-wave radiation. The wind dominated on time scales of days, while the current became important on longer time scales. The drift dynamics showed apparent spatial differences between the eastern and western regions, as well as between the Antarctic Circumpolar Current and the rest of the Weddell Sea. Inertial motion was present in regions of low ice concentration. The surface heterogeneity, arising e.g. from roughness or temperature distribution, poses a problem for the parameterization of surface exchange processes in large-scale models. In the case of neutral flow over a heterogeneous terrain, an effective roughness length can be used to parameterize the roughness effects

  7. NOAA Climate Data Record (CDR) of Ocean Near Surface Atmospheric Properties, Version 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Ocean Surface Bundle (OSB) Climate Data Record (CDR) consist of three parts: sea surface temperature; near-surface wind speed, air temperature, and specific...

  8. International Comprehensive Ocean-Atmosphere Data Set (ICOADS) R3.0 netCDF version

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains observations of global ocean meteorological and oceanographic variables, such as sea surface and air temperatures, wind, pressure, humidity,...

  9. Skill Assessment of a Spectral Ocean-Atmosphere Radiative Model

    Science.gov (United States)

    Gregg, Watson, W.; Casey, Nancy W.

    2009-01-01

    Ocean phytoplankton, detrital material, and water absorb and scatter light spectrally. The Ocean- Atmosphere Spectral Irradiance Model (OASIM) is intended to provide surface irradiance over the oceans with sufficient spectral resolution to support ocean ecology, biogeochemistry, and heat exchange investigations, and of sufficient duration to support inter-annual and decadal investigations. OASIM total surface irradiance (integrated 200 nm to 4 microns) was compared to in situ data and three publicly available global data products at monthly 1-degree resolution. OASIM spectrally-integrated surface irradiance had root mean square (RMS) difference= 20.1 W/sq m (about 11%), bias=1.6 W/sq m (about 0.8%), regression slope= 1.01 and correlation coefficient= 0.89, when compared to 2322 in situ observations. OASIM had the lowest bias of any of the global data products evaluated (ISCCP-FD, NCEP, and ISLSCP 11), and the best slope (nearest to unity). It had the second best RMS, and the third best correlation coefficient. OASIM total surface irradiance compared well with ISCCP-FD (RMS= 20.7 W/sq m; bias=-11.4 W/sq m, r=0.98) and ISLSCP II (RMS =25.2 W/sq m; bias= -13.8 W/sq m; r=0.97), but less well with NCEP (RMS =43.0 W/sq m ;bias=-22.6 W/sq m; x=0.91). Comparisons of OASIM photosynthetically available radiation (PAR) with PAR derived from SeaWiFS showed low bias (-1.8 mol photons /sq m/d, or about 5%), RMS (4.25 mol photons /sq m/d ' or about 12%), near unity slope (1.03) and high correlation coefficient (0.97). Coupled with previous estimates of clear sky spectral irradiance in OASIM (6.6% RMS at 1 nm resolution), these results suggest that OASIM provides reasonable estimates of surface broadband and spectral irradiance in the oceans, and can support studies on ocean ecosystems, carbon cycling, and heat exchange.

  10. Key features of the IPSL ocean atmosphere model and its sensitivity to atmospheric resolution

    Energy Technology Data Exchange (ETDEWEB)

    Marti, Olivier; Braconnot, P.; Bellier, J.; Brockmann, P.; Caubel, A.; Noblet, N. de; Friedlingstein, P.; Idelkadi, A.; Kageyama, M. [Unite Mixte CEA-CNRS-UVSQ, IPSL/LSCE, Gif-sur-Yvette Cedex (France); Dufresne, J.L.; Bony, S.; Codron, F.; Fairhead, L.; Grandpeix, J.Y.; Hourdin, F.; Musat, I. [Unite Mixte CNRS-Ecole Polytechnique-ENS-UPCM, IPSL/LMD, Paris Cedex 05 (France); Benshila, R.; Guilyardi, E.; Levy, C.; Madec, G.; Mignot, J.; Talandier, C. [unite mixte CNRS-IRD-UPMC, IPLS/LOCEAN, Paris Cedex 05 (France); Cadule, P.; Denvil, S.; Foujols, M.A. [Institut Pierre Simon Laplace des Sciences de l' Environnement (IPSL), Paris Cedex 05 (France); Fichefet, T.; Goosse, H. [Universite Catholique de Louvain, Institut d' Astronomie et de Geophysique Georges Lemaitre, Louvain-la-Neuve (Belgium); Krinner, G. [Unite mixte CNRS-UJF Grenoble, LGGE, BP96, Saint-Martin-d' Heres (France); Swingedouw, D. [CNRS/CERFACS, Toulouse (France)

    2010-01-15

    This paper presents the major characteristics of the Institut Pierre Simon Laplace (IPSL) coupled ocean-atmosphere general circulation model. The model components and the coupling methodology are described, as well as the main characteristics of the climatology and interannual variability. The model results of the standard version used for IPCC climate projections, and for intercomparison projects like the Paleoclimate Modeling Intercomparison Project (PMIP 2) are compared to those with a higher resolution in the atmosphere. A focus on the North Atlantic and on the tropics is used to address the impact of the atmosphere resolution on processes and feedbacks. In the North Atlantic, the resolution change leads to an improved representation of the storm-tracks and the North Atlantic oscillation. The better representation of the wind structure increases the northward salt transports, the deep-water formation and the Atlantic meridional overturning circulation. In the tropics, the ocean-atmosphere dynamical coupling, or Bjerknes feedback, improves with the resolution. The amplitude of ENSO (El Nino-Southern oscillation) consequently increases, as the damping processes are left unchanged. (orig.)

  11. Biogeochemical linkage between atmosphere and ocean in the eastern equatorial Pacific Ocean: Results from the EqPOS research cruise

    Science.gov (United States)

    Furutani, H.; Inai, Y.; Aoki, S.; Honda, H.; Omori, Y.; Tanimoto, H.; Iwata, T.; Ueda, S.; Miura, K.; Uematsu, M.

    2012-12-01

    Eastern equatorial Pacific Ocean is a unique oceanic region from several biogeochemical points of view. It is a remote open ocean with relatively high marine biological activity, which would result in limited influence of human activity but enhanced effect of marine natural processes on atmospheric composition. It is also characterized as high nutrient low chlorophyll (HNLC) ocean, in which availability of trace metals such as iron and zinc limits marine primary production and thus atmospheric deposition of these trace elements to the ocean surface is expected to play an important role in regulating marine primary production and defining unique microbial community. High sea surface temperature in the region generates strong vertical air convection which efficiently brings tropospheric atmospheric composition into stratosphere. In this unique eastern equatorial Pacific Ocean, EqPOS (Equatorial Pacific Ocean and Stratospheric/Tropospheric Atmospheric Study) research cruise was organized as a part of SOLAS Japan activity to understand biogeochemical ocean-atmospheric interaction in the region. Coordinated atmospheric, oceanic, and marine biological observations including sampling/characterization of thin air-sea interfacial layer (sea surface microlayer: SML) and launching large stratospheric air sampling balloons were carried out on-board R/V Hakuho Maru starting from 29 January for 39 days. Biogeochemically important trace/long-lived gases such as CO2, dimethyl sulfide (DMS), and some volatile organic carbons (VOCs) both in the atmosphere and seawater were continuously monitored and their air-sea fluxes were also observed using gradient and eddy-covariance techniques. Atmospheric gas measurement of CO2, CH4, N2O, SF6, CO, H2, Ar and isotopic composition of selected gases were further extended to stratospheric air by balloon-born sampling in addition to a vertical profiling of O3, CO2, and H2O with sounding sondes. Physical and chemical properties of marine

  12. Variability, interaction and change in the atmosphere-ocean-ecology system of the Western Indian Ocean.

    Science.gov (United States)

    Spencer, T; Laughton, A S; Flemming, N C

    2005-01-15

    Traditional ideas of intraseasonal and interannual climatic variability in the Western Indian Ocean, dominated by the mean cycle of seasonally reversing monsoon winds, are being replaced by a more complex picture, comprising air-sea interactions and feedbacks; atmosphere-ocean dynamics operating over intrannual to interdecadal time-scales; and climatological and oceanographic boundary condition changes at centennial to millennial time-scales. These forcings, which are mediated by the orography of East Africa and the Asian continent and by seafloor topography (most notably in this area by the banks and shoals of the Mascarene Plateau which interrupts the westward-flowing South Equatorial Current), determine fluxes of water, nutrients and biogeochemical constituents, the essential controls on ocean and shallow-sea productivity and ecosystem health. Better prediction of climatic variability for rain-fed agriculture, and the development of sustainable marine resource use, is of critical importance to the developing countries of this region but requires further basic information gathering and coordinated ocean observation systems.

  13. The oceanic cycle and global atmospheric budget of carbonyl sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, P.S.

    1994-12-31

    A significant portion of stratospheric air chemistry is influenced by the existence of carbonyl sulfide (COS). This ubiquitous sulfur gas represents a major source of sulfur to the stratosphere where it is converted to sulfuric acid aerosol particles. Stratospheric aerosols are climatically important because they scatter incoming solar radiation back to space and are able to increase the catalytic destruction of ozone through gas phase reactions on particle surfaces. COS is primarily formed at the surface of the earth, in both marine and terrestrial environments, and is strongly linked to natural biological processes. However, many gaps in the understanding of the global COS cycle still exist, which has led to a global atmospheric budget that is out of balance by a factor of two or more, and a lack of understanding of how human activity has affected the cycling of this gas. The goal of this study was to focus on COS in the marine environment by investigating production/destruction mechanisms and recalculating the ocean-atmosphere flux.

  14. The ocean-atmosphere response to wind-induced thermocline changes in the tropical South Western Indian Ocean

    NARCIS (Netherlands)

    Manola, Iris; Selten, F. M.; De Ruijter, W. P M; Hazeleger, W.

    2014-01-01

    In the Indian Ocean basin the sea surface temperatures (SSTs) are most sensitive to changes in the oceanic depth of the thermocline in the region of the Seychelles Dome. Observational studies have suggested that the strong SST variations in this region influence the atmospheric evolution around the

  15. Atmospheric noble gases in Mid-Ocean Ridge Basalts: Identification of atmospheric contamination processes

    Science.gov (United States)

    Roubinet, Claire; Moreira, Manuel A.

    2018-02-01

    Noble gases in oceanic basalts always show the presence in variable proportions of a component having elemental and isotopic compositions that are similar to those of the atmosphere and distinct from the mantle composition. Although this component could be mantle-derived (e.g. subduction of air or seawater-derived noble gases trapped in altered oceanic crust and sediments), it is most often suggested that this air component is added after sample collection and probably during storage at ambient air, although the mechanism remains unknown. In an attempt to reduce this atmospheric component observed in MORBs, four experimental protocols have been followed in this study. These protocols are based on the hypothesis that air can be removed from the samples, as it appears to be sheltered in distinct vesicles compared to those filled with mantle gases. All of the protocols involve a glove box filled with nitrogen, and in certain cases, the samples are stored under primary vacuum (lower than 10-2 mbar) to pump air out or, alternatively, under high pressure of N2 to expel atmospheric noble gases. In all protocols, three components are observed: atmospheric, fractionated atmospheric and magmatic. The fractionated air component seems to be derived from the non-vitreous part of the pillow-lava, which has cooled more slowly. This component is enriched in Ne relative to Ar, reflecting a diffusive process. This contaminant has already been observed in other studies and thus seems to be relatively common. Although it is less visible, unfractionated air has also been detected in some crushing steps, which tends to indicate that despite the experiments, air is still present in the vesicles. This result is surprising, since studies have demonstrated that atmospheric contamination could be limited if samples were stored under nitrogen quickly after their recovery from the seafloor. Thus, the failure of the protocols could be explained by the insufficient duration of these protocols or

  16. Modern and ancient geochemical constraints on Proterozoic atmosphere-ocean redox evolution

    Science.gov (United States)

    Hardisty, D. S.; Horner, T. J.; Wankel, S. D.; Lu, Z.; Lyons, T.; Nielsen, S.

    2017-12-01

    A detailed understanding of the spatiotemporal oxygenation of Earth's atmosphere-ocean system through the Precambrian has important implications for the environments capable of sustaining early eukaryotic life and the evolving oxidant budget of subducted sediments. Proxy records suggest an anoxic Fe-rich deep ocean through much of the Precambrian and atmospheric and surface-ocean oxygenation that started in earnest at the Paleoproterozoic Great Oxidation Event (GOE). The marine photic zone represented the initial site of oxygen production and accumulation via cyanobacteria, yet our understanding of surface-ocean oxygen contents and the extent and timing of oxygen propagation and exchange between the atmosphere and deeper ocean are limited. Here, we present an updated perspective of the constraints on atmospheric, surface-ocean, and deep-ocean oxygen contents starting at the GOE. Our research uses the iodine content of Proterozoic carbonates as a tracer of dissolved iodate in the shallow ocean, a redox-sensitive species quantitatively reduced in modern oxygen minimum zones. We supplement our understanding of the ancient record with novel experiments examining the rates of iodate production from oxygenated marine environments based on seawater incubations. Combining new data from iodine with published shallow marine (Ce anomaly, N isotopes) and atmospheric redox proxies, we provide an integrated view of the vertical redox structure of the atmosphere and ocean across the Proterozoic.

  17. Observational description of the atmospheric and oceanic boundary layers over the Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Marcelo Dourado

    2001-01-01

    Full Text Available Time evolution of atmospheric and oceanic boundary layers are described for an upwelling region in the Atlantic Ocean located in Cabo Frio, Brazil (23°00'S, 42°08'W. The observations were obtained during a field campaign carried out by the "Instituto de Estudos do Mar Almirante Paulo Moreira", on board of the oceanographic ship Antares of the Brazilian Navy, between July 7 and 10 of 1992. The analysis shown here was based on 19 simultaneous vertical soundings of atmosphere and ocean, carried out consecutively every 4 hours. The period of observation was characterized by a passage of a cold front that penetrated in Cabo Frio on July 6. During the cold front passage the vertical extension of atmospheric (and oceanic mixed layer varied from 200 m (and 13 m to 1000 m (and 59 m. These changes occurred in the first day of observation and were followed by an increase of 1.2°C in the oceanic mixed layer temperature and by a decrease of 6 K and 6 g/kg in the virtual potential temperature and specific humidity of the atmospheric mixed layer. The short time scale variations in the ocean can be explained in terms of the substitution of cold upwelling water by warm downwelling water regime, as the surface winds shift from pre-frontal NE to post-frontal SSW during the cold front passage in Cabo Frio. The large vertical extent of the atmospheric mixed layer can be explained in terms of an intensification of the thermal mixing induced by the warming of the oceanic upper layers combined with the cooling of the lower atmospheric layers during the cold front passage. An intensification of the mechanical mixing, observed during the cold front passage, may also be contributing to the observed variations in the vertical extent of both layers.A evolução temporal das camadas limites atmosféricas e oceânicas são descritas para a região de ressurgência do Oceano Atlântico localizada em Cabo Frio. As observações foram obtidas durante a campanha de medidas

  18. Monte Carlo and discrete-ordinate simulations of irradiances in the coupled atmosphere-ocean system.

    Science.gov (United States)

    Gjerstad, Karl Idar; Stamnes, Jakob J; Hamre, Børge; Lotsberg, Jon K; Yan, Banghua; Stamnes, Knut

    2003-05-20

    We compare Monte Carlo (MC) and discrete-ordinate radiative-transfer (DISORT) simulations of irradiances in a one-dimensional coupled atmosphere-ocean (CAO) system consisting of horizontal plane-parallel layers. The two models have precisely the same physical basis, including coupling between the atmosphere and the ocean, and we use precisely the same atmospheric and oceanic input parameters for both codes. For a plane atmosphere-ocean interface we find agreement between irradiances obtained with the two codes to within 1%, both in the atmosphere and the ocean. Our tests cover case 1 water, scattering by density fluctuations both in the atmosphere and in the ocean, and scattering by particulate matter represented by a one-parameter Henyey-Greenstein (HG) scattering phase function. The CAO-MC code has an advantage over the CAO-DISORT code in that it can handle surface waves on the atmosphere-ocean interface, but the CAO-DISORT code is computationally much faster. Therefore we use CAO-MC simulations to study the influence of ocean surface waves and propose a way to correct the results of the CAO-DISORT code so as to obtain fast and accurate underwater irradiances in the presence of surface waves.

  19. Some sensitivities of a coupled ocean-atmosphere GCM

    International Nuclear Information System (INIS)

    Stockdale, T.; Latif, M.; Burgers, G.; Wolff, J.O.

    1994-01-01

    A coupled ocean-atmosphere GCM is being developed for use in seasonal forecasting. As part of the development work, a number of experiments have been made to explore some of the sensitivities of the coupled model system. The overall heat balance of the tropics is found to be very sensitive to convective cloud cover. Adjusting the cloud parameterization to produce stable behaviour of the coupled model also leads to better agreement between model radiative fluxes and satellite data. A further sensitivity is seen to changes in low-level marine stratus, which is under-represented in the initial model experiments. An increase in this cloud in the coupled model produces a small improvement in both the global mean state and the phase of the east Pacific annual cycle. The computational expense of investigating such small changes is emphasized. An indication of model sensitivity to surface albedo is also presented. The sensitivity of the coupled GCM to initial conditions is investigated. The model is very sensitive, with tiny perturbations able to determine El Nino or non-El Nino conditions just six months later. This large sensitivity may be related to the relatively weak amplitude of the model ENSO cycle. (orig.)

  20. Rapid global ocean-atmosphere response to Southern Ocean freshening during the last glacial.

    Science.gov (United States)

    Turney, Chris S M; Jones, Richard T; Phipps, Steven J; Thomas, Zoë; Hogg, Alan; Kershaw, A Peter; Fogwill, Christopher J; Palmer, Jonathan; Bronk Ramsey, Christopher; Adolphi, Florian; Muscheler, Raimund; Hughen, Konrad A; Staff, Richard A; Grosvenor, Mark; Golledge, Nicholas R; Rasmussen, Sune Olander; Hutchinson, David K; Haberle, Simon; Lorrey, Andrew; Boswijk, Gretel; Cooper, Alan

    2017-09-12

    Contrasting Greenland and Antarctic temperatures during the last glacial period (115,000 to 11,650 years ago) are thought to have been driven by imbalances in the rates of formation of North Atlantic and Antarctic Deep Water (the 'bipolar seesaw'). Here we exploit a bidecadally resolved 14 C data set obtained from New Zealand kauri (Agathis australis) to undertake high-precision alignment of key climate data sets spanning iceberg-rafted debris event Heinrich 3 and Greenland Interstadial (GI) 5.1 in the North Atlantic (~30,400 to 28,400 years ago). We observe no divergence between the kauri and Atlantic marine sediment 14 C data sets, implying limited changes in deep water formation. However, a Southern Ocean (Atlantic-sector) iceberg rafted debris event appears to have occurred synchronously with GI-5.1 warming and decreased precipitation over the western equatorial Pacific and Atlantic. An ensemble of transient meltwater simulations shows that Antarctic-sourced salinity anomalies can generate climate changes that are propagated globally via an atmospheric Rossby wave train.A challenge for testing mechanisms of past climate change is the precise correlation of palaeoclimate records. Here, through climate modelling and the alignment of terrestrial, ice and marine 14 C and 10 Be records, the authors show that Southern Ocean freshwater hosing can trigger global change.

  1. Impacts of Atmosphere-Ocean Coupling on Southern Hemisphere Climate Change

    Science.gov (United States)

    Li, Feng; Newman, Paul; Pawson, Steven

    2013-01-01

    Climate in the Southern Hemisphere (SH) has undergone significant changes in recent decades. These changes are closely linked to the shift of the Southern Annular Mode (SAM) towards its positive polarity, which is driven primarily by Antarctic ozone depletion. There is growing evidence that Antarctic ozone depletion has significant impacts on Southern Ocean circulation change. However, it is poorly understood whether and how ocean feedback might impact the SAM and climate change in the SH atmosphere. This outstanding science question is investigated using the Goddard Earth Observing System Coupled Atmosphere-Ocean-Chemistry Climate Model(GEOS-AOCCM).We perform ensemble simulations of the recent past (1960-2010) with and without the interactive ocean. For simulations without the interactive ocean, we use sea surface temperatures and sea ice concentrations produced by the interactive ocean simulations. The differences between these two ensemble simulations quantify the effects of atmosphere-ocean coupling. We will investigate the impacts of atmosphere-ocean coupling on stratospheric processes such as Antarctic ozone depletion and Antarctic polar vortex breakup. We will address whether ocean feedback affects Rossby wave generation in the troposphere and wave propagation into the stratosphere. Another focuson this study is to assess how ocean feedback might affect the tropospheric SAM response to Antarctic ozone depletion

  2. GESAMP Working Group 38, The Atmospheric Input of Chemicals to the Ocean

    Science.gov (United States)

    Duce, Robert; Liss, Peter

    2014-05-01

    There is growing recognition of the impact of the atmospheric input of both natural and anthropogenic substances on ocean chemistry, biology, and biogeochemistry as well as climate. These inputs are closely related to a number of important global change issues. For example, the increasing input of anthropogenic nitrogen species from the atmosphere to much of the ocean may cause a low level fertilization that could result in an increase in marine 'new' productivity of up to ~3% and thus impact carbon drawdown from the atmosphere. Similarly, much of the oceanic iron, which is a limiting nutrient in significant areas of the ocean, originates from the atmospheric input of minerals as a result of the long-range transport of mineral dust from continental regions. The increased supply of soluble phosphorus from atmospheric anthropogenic sources (through large-scale use of fertilizers) may also have a significant impact on surface-ocean biogeochemistry, but estimates of any effects are highly uncertain. There have been few assessments of the atmospheric inputs of sulfur and nitrogen oxides to the ocean and their impact on the rates of ocean acidification. These inputs may be particularly critical in heavily trafficked shipping lanes and in ocean regions proximate to highly industrialized land areas. Other atmospheric substances may also have an impact on the ocean, in particular lead, cadmium, and POPs. To address these and related issues the United Nations Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) initiated Working Group 38, The Atmospheric Input of Chemicals to the Ocean, in 2008. This Working Group has had four meetings. To date four peer reviewed papers have been produced from this effort, with a least eight others in the process of being written or published. This paper will discuss some of the results of the Working Group's deliberations and its plans for possible future work.

  3. Atmospheric and Oceanic Response to Southern Ocean Deep Convection Oscillations on Decadal to Centennial Time Scales in Climate Models

    Science.gov (United States)

    Martin, T.; Reintges, A.; Park, W.; Latif, M.

    2014-12-01

    Many current coupled global climate models simulate open ocean deep convection in the Southern Ocean as a recurring event with time scales ranging from a few years to centennial (de Lavergne et al., 2014, Nat. Clim. Ch.). The only observation of such event, however, was the occurrence of the Weddell Polynya in the mid-1970s, an open water area of 350 000 km2 within the Antarctic sea ice in three consecutive winters. Both the wide range of modeled frequency of occurrence and the absence of deep convection in the Weddell Sea highlights the lack of understanding concerning the phenomenon. Nevertheless, simulations indicate that atmospheric and oceanic responses to the cessation of deep convection in the Southern Ocean include a strengthening of the low-level atmospheric circulation over the Southern Ocean (increasing SAM index) and a reduction in the export of Antarctic Bottom Water (AABW), potentially masking the regional effects of global warming (Latif et al., 2013, J. Clim.; Martin et al., 2014, Deep Sea Res. II). It is thus of great importance to enhance our understanding of Southern Ocean deep convection and clarify the associated time scales. In two multi-millennial simulations with the Kiel Climate Model (KCM, ECHAM5 T31 atmosphere & NEMO-LIM2 ~2˚ ocean) we showed that the deep convection is driven by strong oceanic warming at mid-depth periodically overriding the stabilizing effects of precipitation and ice melt (Martin et al., 2013, Clim. Dyn.). Sea ice thickness also affects location and duration of the deep convection. A new control simulation, in which, amongst others, the atmosphere grid resolution is changed to T42 (~2.8˚), yields a faster deep convection flip-flop with a period of 80-100 years and a weaker but still significant global climate response similar to CMIP5 simulations. While model physics seem to affect the time scale and intensity of the phenomenon, the driving mechanism is a rather robust feature. Finally, we compare the atmospheric and

  4. Scaling laws for perturbations in the ocean-atmosphere system following large CO2 emissions

    Science.gov (United States)

    Towles, N.; Olson, P.; Gnanadesikan, A.

    2015-07-01

    Scaling relationships are found for perturbations to atmosphere and ocean variables from large transient CO2 emissions. Using the Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir (LOSCAR) model (Zeebe et al., 2009; Zeebe, 2012b), we calculate perturbations to atmosphere temperature, total carbon, ocean temperature, total ocean carbon, pH, alkalinity, marine-sediment carbon, and carbon-13 isotope anomalies in the ocean and atmosphere resulting from idealized CO2 emission events. The peak perturbations in the atmosphere and ocean variables are then fit to power law functions of the form of γ DαEβ, where D is the event duration, E is its total carbon emission, and γ is a coefficient. Good power law fits are obtained for most system variables for E up to 50 000 PgC and D up to 100 kyr. Although all of the peak perturbations increase with emission rate E/D, we find no evidence of emission-rate-only scaling, α + β = 0. Instead, our scaling yields α + β ≃ 1 for total ocean and atmosphere carbon and 0 < α + β < 1 for most of the other system variables.

  5. A highly oxidized atmosphere-ocean system and oceanic molybdenum drawdown during the Paleoproterozoic

    Science.gov (United States)

    Goto, K. T.; Ito, T.; Suzuki, K.; Anbar, A. D.; Gordon, G. W.; Kashiwabara, T.; Takaya, Y.; Shimoda, G.; Nozaki, T.; Kiyokawa, S.; Tetteh, G. M.; Nyame, F. K.

    2014-12-01

    Multiple lines of evidence suggest that the first major oxidation of the atmosphere-ocean system occurred during the Paleoproterozoic. However, the course of this redox transition remains elusive. A number of large Mn deposits are distributed in Paleoproterozoic sedimentary successions. As Mn is a redox-sensitive element characterized by high redox potential, knowledge of the Mn cycle in Paleoproterozoic seawater may provide insight into redox evolution during this period. Here, we investigate the Mn cycle in Paleoproterozoic seawater based on the Re-Os and Mo isotope compositions, and the abundance of major and trace elements, in Mn-rich sedimentary rocks from the Nsuta deposit of the Birimian Supergroup, Ghana. The Mn ore is composed mainly of rhodochrosite and is distributed at the boundaries between sedimentary rocks and tholeiitic volcanic rocks. The Re-Os isochron age (2217 ± 100 Ma) we obtained was consistent with U-Pb zircon ages of the volcanic rocks. The manganophile elements, except for Mo, show no enrichment, which is similar to modern hydrothermal Mn oxides. The PAAS-normalized REE compositions show positive Ce anomaly, indicative of Ce enrichment due to the oxidation of Ce(III) by Mn(IV). These findings suggest that Mn ore formed from primary precipitation of Mn oxides from hydrothermal fluids as they were mixed with bottom seawater at ~2.2 Ga. Thus, the bottom seawater would have been sufficiently oxygenated for the precipitation of Mn oxides at ~2.2 Ga. The Nsuta ore samples exhibit slight Mo enrichment, but Mo/Mn ratios are orders of magnitude lower than those in modern hydrothermal Mn oxides. We also found that the Mo isotopes in the Nsuta ore are ~0.7‰ heavier than those in modern hydrothermal and hydrogenous Mn oxides. As Mo in hydrothermal Mn oxides is sourced primarily from seawater (Goto et al., in prep), these results may reflect smaller oceanic Mo inventory and heavier seawater Mo isotope composition at 2.2 Ga than those of present

  6. Evolution of the Atmosphere and Oceans: Evidence from Geological ...

    Indian Academy of Sciences (India)

    The Archaean ocean was probably a soda ocean rich in NaZC03 and NaHC0. 3 ... times those of the present to account for an equable climate in the wake of lower ..... attributed these textural changes to a decline in carbonate satu-. Box 2.

  7. Evolution of the Atmosphere and Oceans: Evidence from Geological ...

    Indian Academy of Sciences (India)

    The proto-ocean owes its origin to condensation of water vapour from the ...... ter SO /- is -20 0/00)' This change is considered to be a conse- quence of either ... Earth's climate and the origin of the oceans, Palaeogeography, 146,33-. 51.

  8. NOAA Climate Data Record (CDR) of Ocean Near Surface Atmospheric Properties, Version 1 (Version Superseded)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Please note, this dataset has been superseded by a newer version (see below). Users should not use this version except in rare cases (e.g., when reproducing previous...

  9. GFDL CM2.1 Global Coupled Ocean-Atmosphere Model Water ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. GFDL CM2.1 Global Coupled Ocean-Atmosphere Model Water Hosing Experiment with 1 Sv equivalent of Freshening Control Expt: 100 yrs After Hosing: 300 yrs.

  10. Ocean-Atmosphere Coupling Processes Affecting Predictability in the Climate System

    Science.gov (United States)

    Miller, A. J.; Subramanian, A. C.; Seo, H.; Eliashiv, J. D.

    2017-12-01

    Predictions of the ocean and atmosphere are often sensitive to coupling at the air-sea interface in ways that depend on the temporal and spatial scales of the target fields. We will discuss several aspects of these types of coupled interactions including oceanic and atmospheric forecast applications. For oceanic mesoscale eddies, the coupling can influence the energetics of the oceanic flow itself. For Madden-Julian Oscillation onset, the coupling timestep should resolve the diurnal cycle to properly raise time-mean SST and latent heat flux prior to deep convection. For Atmospheric River events, the evolving SST field can alter the trajectory and intensity of precipitation anomalies along the California coast. Improvements in predictions will also rely on identifying and alleviating sources of biases in the climate states of the coupled system. Surprisingly, forecast skill can also be improved by enhancing stochastic variability in the atmospheric component of coupled models as found in a multiscale ensemble modeling approach.

  11. Atmospheric moisture transport and fresh water flux over oceans derived from spacebased sensors

    Science.gov (United States)

    Liu, W. T.; Tang, W.

    2001-01-01

    preliminary results will be shown to demonstrate the application of spacebased IMT and fresh water flux in ocean-atmosphere-land interaction studies, such as the hydrologica balance on Amazon rainfall and Indian monsoon.

  12. Modeling of radiation transport in coupled atmosphere-snow-ice-ocean systems

    International Nuclear Information System (INIS)

    Stamnes, K.; Hamre, B.; Stamnes, J. J.; Ryzhikov, G.; Biryulina, M.

    2009-01-01

    A radiative transfer model for coupled atmosphere-snow-ice-ocean systems is used to develop accurate and efficient tools for computing the BRDF of sea ice for a wide range of situations occurring in nature. (authors)

  13. On Verifying Currents and Other Features in the Hawaiian Islands Region Using Fully Coupled Ocean/Atmosphere Mesoscale Prediction System Compared to Global Ocean Model and Ocean Observations

    Science.gov (United States)

    Jessen, P. G.; Chen, S.

    2014-12-01

    This poster introduces and evaluates features concerning the Hawaii, USA region using the U.S. Navy's fully Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS-OS™) coupled to the Navy Coastal Ocean Model (NCOM). It also outlines some challenges in verifying ocean currents in the open ocean. The system is evaluated using in situ ocean data and initial forcing fields from the operational global Hybrid Coordinate Ocean Model (HYCOM). Verification shows difficulties in modelling downstream currents off the Hawaiian islands (Hawaii's wake). Comparing HYCOM to NCOM current fields show some displacement of small features such as eddies. Generally, there is fair agreement from HYCOM to NCOM in salinity and temperature fields. There is good agreement in SSH fields.

  14. The role of Southern Ocean mixing and upwelling in glacial-interglacial atmospheric CO2 change

    International Nuclear Information System (INIS)

    Watson, Andrew J.; Naveira Garabato, Alberto C.

    2006-01-01

    Decreased ventilation of the Southern Ocean in glacial time is implicated in most explanations of lower glacial atmospheric CO 2 . Today, the deep (>2000 m) ocean south of the Polar Front is rapidly ventilated from below, with the interaction of deep currents with topography driving high mixing rates well up into the water column. We show from a buoyancy budget that mixing rates are high in all the deep waters of the Southern Ocean. Between the surface and 2000 m depth, water is upwelled by a residual meridional overturning that is directly linked to buoyancy fluxes through the ocean surface. Combined with the rapid deep mixing, this upwelling serves to return deep water to the surface on a short time scale. We propose two new mechanisms by which, in glacial time, the deep Southern Ocean may have been more isolated from the surface. Firstly, the deep ocean appears to have been more stratified because of denser bottom water resulting from intense sea ice formation near Antarctica. The greater stratification would have slowed the deep mixing. Secondly, subzero atmospheric temperatures may have meant that the present-day buoyancy flux from the atmosphere to the ocean surface was reduced or reversed. This in turn would have reduced or eliminated the upwelling (contrary to a common assumption, upwelling is not solely a function of the wind stress but is coupled to the air/sea buoyancy flux too). The observed very close link between Antarctic temperatures and atmospheric CO 2 could then be explained as a natural consequence of the connection between the air/sea buoyancy flux and upwelling in the Southern Ocean, if slower ventilation of the Southern Ocean led to lower atmospheric CO 2 . Here we use a box model, similar to those of previous authors, to show that weaker mixing and reduced upwelling in the Southern Ocean can explain the low glacial atmospheric CO 2 in such a formulation

  15. Intermediate Models of Planetary Circulations in the Atmosphere and Ocean.

    Science.gov (United States)

    McWilliams, James C.; Gent, Peter R.

    1980-08-01

    Large-scale extratropical motions (with dimensions comparable to, or somewhat smaller than, the planetary radius) in the atmosphere and ocean exhibit a more restricted range of phenomena than are admissible in the primitive equations for fluid motions, and there have been many previous proposals for simpler, more phenomenologically limited models of these motions. The oldest and most successful of these is the quasi-geostrophic model. An extensive discussion is made of models intermediate between the quasi-geostrophic and primitive ones, some of which have been previously proposed [e.g., the balance equations (BE), where tendencies in the equation for the divergent component of velocity are neglected, or the geostrophic momentum approximation (GM), where ageostrophic accelerations are neglected relative to geostrophic ones] and some of which are derived here. Virtues of these models are assessed in the dual measure of nearly geostrophic momentum balance (i.e., small Rossby number) and approximate frontal structure (i.e., larger along-axis velocities and length scales than their cross-axis counterparts), since one or both of these circumstances is usually characteristic of planetary motions. Consideration is also given to various coordinate transformations, since they can yield simpler expressions for the governing differential equations of the intermediate models. In particular, a new set of coordinates is proposed, isentropic geostrophic coordinates,(IGC), which has the advantage of making implicit the advections due to ageostrophic horizontal and vertical velocities under various approximations. A generalization of quasi-geostrophy is made. named hypo-geostrophy (HG), which is an asymptotic approximation of one higher order accuracy in Rossby number. The governing equations are simplest in IGC for both HG and GM; we name the latter in these coordinates isentropic semi-geostrophy (ISG), in analogy to Hoskins' (1975) semi-geostrophy (SG). HG, GM and BE are, in our

  16. Physical and meteorological data from the seventy moorings of the Tropical Atmosphere/Ocean (TAO) Project in the Tropical Pacific Ocean, 1979-2002 (NODC Accession 0000727)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and meteorological data were collected in the Tropical Pacific Ocean from 29 January 1979 to 03 November 2001. Data were collected by the Pacific Marine...

  17. 76 FR 64327 - Office of Oceanic and Atmospheric Research Draft Strategic Plan

    Science.gov (United States)

    2011-10-18

    ...: 111003608-1608-01] Office of Oceanic and Atmospheric Research Draft Strategic Plan AGENCY: Office of Oceanic... notice announces that OAR's draft Strategic Plan (FY12- 18) is available for public review and comment... next six years. These goals and objectives will provide guidance and strategic direction for program...

  18. Models for changes in atmospheric carbon dioxide, ocean geochemistry and circulation during the late Pleistocene

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.; SenGupta, R.

    in oceanic alkalinity (and hence a decrease in atmospheric CO@d2@@) due to CaCO@d3@@ compensation. A likely mechanism for this rearrangement could be an orbital-forced insolation related increase in biological production in the Southern Ocean. This, coupled...

  19. A vector radiative transfer model for coupled atmosphere and ocean systems with a rough interface

    International Nuclear Information System (INIS)

    Zhai Pengwang; Hu Yongxiang; Chowdhary, Jacek; Trepte, Charles R.; Lucker, Patricia L.; Josset, Damien B.

    2010-01-01

    We report on an exact vector (polarized) radiative transfer (VRT) model for coupled atmosphere and ocean systems. This VRT model is based on the successive order of scattering (SOS) method, which virtually takes all the multiple scattering processes into account, including atmospheric scattering, oceanic scattering, reflection and transmission through the rough ocean surface. The isotropic Cox-Munk wave model is used to derive the ref and transmission matrices for the rough ocean surface. Shadowing effects are included by the shadowing function. We validated the SOS results by comparing them with those calculated by two independent codes based on the doubling/adding and Monte Carlo methods. Two error analyses related to the ocean color remote sensing are performed in the coupled atmosphere and ocean systems. One is the scalar error caused by ignoring the polarization in the whole system. The other is the error introduced by ignoring the polarization of the light transmitted through the ocean interface. Both errors are significant for the cases studied. This code fits for the next generation of ocean color study because it converges fast for absorbing medium as, for instance, ocean.

  20. Multi-wavelength Ocean Profiling and Atmospheric Lidar

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to build and demonstrate the world's first multi-wavelength ocean-profiling high spectral resolution lidar (HSRL). The lidar will provide profiles of...

  1. Ocean biogeochemistry and atmospheric composition: Significance of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.; Jayakumar, D.A.

    -deficiency at mid-depths in this region modulates oceanic combined nitrogen inventory and consequently biological productivity. Due to a delicate biogeochemical balance the Arabian Sea is expected to be among the first to react to potential anthropogenic...

  2. Atmospheric and oceanic excitation of decadal-scale Earth orientation variations

    Science.gov (United States)

    Gross, Richard S.; Fukumori, Ichiro; Menemenlis, Dimitris

    2005-09-01

    The contribution of atmospheric wind and surface pressure and oceanic current and bottom pressure variations during 1949-2002 to exciting changes in the Earth's orientation on decadal timescales is investigated using an atmospheric angular momentum series computed from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis project and an oceanic angular momentum series computed from a near-global ocean model that was forced by surface fluxes from the NCEP/NCAR reanalysis project. Not surprisingly, since decadal-scale variations in the length of day are caused mainly by interactions between the mantle and core, the effect of the atmosphere and oceans is found to be only about 14% of that observed. More surprisingly, it is found that the effect of atmospheric and oceanic processes on decadal-scale changes in polar motion is also only about 20% (x component) and 38% (y component) of that observed. Therefore redistribution of mass within the atmosphere and oceans does not appear to be the main cause of the Markowitz wobble. It is also found that on timescales between 10 days and 4 years the atmospheric and oceanic angular momentum series used here have very little skill in explaining Earth orientation variations before the mid to late 1970s. This is attributed to errors in both the Earth orientation observations prior to 1976 when measurements from the accurate space-geodetic techniques became available and to errors in the modeled atmospheric fields prior to 1979 when the satellite era of global weather observing systems began.

  3. Processes analysis of ocean-atmosphere interaction in Colombian marine areas

    International Nuclear Information System (INIS)

    Melo, Jeimmy; Pabon Caicedo, Jose Daniel

    2002-01-01

    This document shows the importance to understanding the processes of interaction ocean-atmosphere by means of the knowledge of the behavior of the physical and biological processes in the Colombian marine areas. For such aim, it was studied the production of the pigment concentration (chlorophyll-a) by means the state of the sea surface temperature and the atmospheric dynamics for year 2001

  4. Atmospheric radiocarbon as a Southern Ocean wind proxy over the last 1000 years

    Science.gov (United States)

    Rodgers, K. B.; Mikaloff Fletcher, S.; Galbraith, E.; Sarmiento, J. L.; Gnanadesikan, A.; Slater, R. D.; Naegler, T.

    2009-04-01

    Measurements of radiocarbon in tree rings over the last 1000 years indicate that there was a pre-industrial latitudinal gradient of atmospheric radiocarbon of 3.9-4.5 per mail and that this gradient had temporal variability of order 6 per mil. Here we test the idea that the mean gradient as well as variability in he gradient is dominated by the strength of the winds over the Southern Ocean. This is done using an ocean model and an atmospheric transport model. The ocean model is used to derive fluxes of 12CO2 and 14CO2 at the sea surface, and these fluxes are used as a lower boundary condition for the transport model. For the mean state, strong winds in the Southern Ocean drive significant upwelling of radiocarbon-depleted Circumpolar Deep Water (CDW), leading to a net flux of 14CO2 relative to 12CO2 into the ocean. This serves to maintain a hemispheric gradient in pre-anthropogenic atmospheric delta-c14. For perturbations, increased/decreased Southern Ocean winds drive increased/decreased uptake of 14CO2 relative to 12CO2, thus increasing/decreasing the hemispheric gradient in atmospheric delta-c14. The tree ring data is interpreted to reveal a decrease in the strength of the Southern Ocean winds at the transition between the Little Ice Age and the Medieval Warm Period.

  5. Predicted net efflux of radiocarbon from the ocean and increase in atmospheric radiocarbon content

    Science.gov (United States)

    Caldeira, Ken; Rau, Greg H.; Duffy, Philip B.

    Prior to changes introduced by man, production of radiocarbon (14C) in the stratosphere nearly balanced the flux of 14C from the atmosphere to the ocean and land biosphere, which in turn nearly balanced radioactive decay in these 14C reservoirs. This balance has been altered by land-use changes, fossil-fuel burning, and atmospheric nuclear detonations. Here, we use a model of the global carbon cycle to quantify these radiocarbon fluxes and make predictions about their magnitude in the future. Atmospheric nuclear detonations increased atmospheric 14C content by about 80% by the mid-1960's. Since that time, the 14C content of the atmosphere has been diminishing as this bomb radiocarbon has been entering the oceans and terrestrial biosphere. However, we predict that atmospheric 14C content will reach a minimum and start to increase within the next few years if fossil-fuel burning continues according to a “business-as-usual” scenario, even though fossil fuels are devoid of 14C. This will happen because fossil-fuel carbon diminishes the net flux of 14C from the atmosphere to the oceans and land biosphere, forcing 14C to accumulate in the atmosphere. Furthermore, the net flux of both bomb and natural 14C into the ocean are predicted to continue to slow and then, in the middle of the next century, to reverse, so that there will be a net flux of 14C from the ocean to the atmosphere. The predicted reversal of net 14C fluxes into the ocean is a further example of human impacts on the global carbon cycle.

  6. The Middle Miocene climate as modelled in an atmosphere-ocean-biosphere model

    Directory of Open Access Journals (Sweden)

    M. Krapp

    2011-11-01

    Full Text Available We present simulations with a coupled atmosphere-ocean-biosphere model for the Middle Miocene 15 million years ago. The model is insofar more consistent than previous models because it captures the essential interactions between ocean and atmosphere and between atmosphere and vegetation. The Middle Miocene topography, which alters both large-scale ocean and atmospheric circulations, causes a global warming of 0.7 K compared to present day. Higher than present-day CO2 levels of 480 and 720 ppm cause a global warming of 2.8 and 4.9 K. The associated water vapour feedback enhances the greenhouse effect which leads to a polar amplification of the warming. These results suggest that higher than present-day CO2 levels are necessary to drive the warm Middle Miocene climate, also because the dynamic vegetation model simulates a denser vegetation which is in line with fossil records. However, we do not find a flatter than present-day equator-to-pole temperature gradient as has been suggested by marine and terrestrial proxies. Instead, a compensation between atmospheric and ocean heat transport counteracts the flattening of the temperature gradient. The acclaimed role of the large-scale ocean circulation in redistributing heat cannot be supported by our results. Including full ocean dynamics, therefore, does not solve the problem of the flat temperature gradient during the Middle Miocene.

  7. Numerical studies on the interaction between atmosphere and ocean using different kinds of parallel computers

    International Nuclear Information System (INIS)

    Lee, Soon-Hwan; Chino, Masamichi

    2000-01-01

    The coupling between atmosphere and ocean model has physical and computational difficulties for short-term forecasting of weather and ocean current. In this research, a combination system between high-resolution meso-scale atmospheric model and ocean model has been constructed using a new message-passing library, called Stampi (Seamless Thinking Aid Message Passing Interface), for prediction of particle dispersion at emergency nuclear accident. Stampi, which is based on the MPI (Message Passing Interface) 2 specification, makes us carry out parallel calculations of combination system without parallelization skill to model code. And it realizes dynamic process creation on different machines and communication between spawned one within the scope of MPI semantics. The models included in this combination system are PHYSIC as an atmosphere model, and POM (Princeton Ocean Model) as an ocean model. We applied this combination system to predict sea surface current at Sea of Japan in winter season. Simulation results indicate that the wind stress near the sea surface tends to be a predominant factor to determine surface ocean currents and dispersion of radioactive contamination in the ocean. The surface ocean current is well correspondent with wind direction, induced by high mountains at North Korea. The satellite data of NSCAT (NASA-SCATterometer), which is an image of sea surface current, also agrees well with the results of this system. (author)

  8. Atmospheric processing of combustion aerosols as a source of soluble iron to the open ocean

    OpenAIRE

    伊藤, 彰記; ITO, Akinori

    2015-01-01

    The majority of bioavailable iron (Fe) from the atmosphere is delivered from arid and semiarid regions to the oceans because the global deposition of iron from combustion sources is small compared with that from mineral dust. Atmospheric processing of mineral aerosols by inorganic and organic acids from anthropogenic and natural sources has been shown to increase the iron solubility of soils (initially < 0.5%) up to about 10%. On the other hand, atmospheric observations have shown that iron i...

  9. Effect of Atmospheric Organics on Bioavailable Fe Lifetime in the Oceans

    Science.gov (United States)

    Meskhidze, Nicholas; Hurley, David; Royalty, Taylor Michael; Johnson, Matthew S.

    2016-01-01

    The deposition of atmospheric aerosols is an important supply pathway of soluble iron (sol-Fe) to the global oceans influencing marine ecosystem processes and climate. Previous studies have shown that natural and anthropogenic acidic trace gases, when mixed with mineral dust, can lead to production of sol-Fe, leading to considerable increase in dust-Fe solubility. Recent studies have further highlighted the importance of atmospheric organic compounds/ligands in the production of sol-Fe during atmospheric transport and transformation of mineral aerosols. However, the actual scope of this aerosol sol-Fe for stimulating the primary productivity in the oceans is determined by both: the total atmospheric fluxes of sol-Fe and the lifetime of sol-Fe after its deposition to the ocean. In this study several atmospheric organic ligands were investigated for their effect on the lifetime of sol-Fe after mixing with seawater. Organic ligands were selected based on their abundance in the marine boundary layer and rainwater and their ability to form bidentate complexes with Fe. The results reveal that the tested organics had minor influence on Fe(II) lifetime in seawater. However, results also show that some organic acid considerably extended the lifetime of colloidal and aqueous Fe(III). Using these results we simulate aerosol sol-Fe lifetime in the ocean for different mineral dust deposition events in the presence and the absence of atmospheric organic ligands. The calculations suggest that when a large dust plume is assumed to contain Fe(II) alone, less than 15% of aerosol sol-Fe gets complexed with marine organic ligands. However, this fraction increases to over 90% when atmospheric Fe is allowed to bond with atmospheric organic acids prior to deposition to the oceans. Calculations also show that for the conditions when seawater organic ligands get titrated by Fe released from dust aerosol particles, retention of sol-Fe in the ocean depends on surface ocean mixing, i

  10. Biogeochemical ocean-atmosphere transfers in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.; Bange, H.W.; Gibb, S.W.; Goyet, C.; Hatton, A.D.; Upstill-Goddard, R.C.

    Transfers of some important biogenic atmospheric constituents, carbon dioxide (CO sub (2)), methane (CH Sub (4)), molecular nitrogen (N sub (2)), nitrous oxide (N sub (2) O), nitrate NO super(-) sub (3) , ammonia (NH sub(3)), methylamines (MAs...

  11. Physical and meteorological delayed-mode full-resolution data from the Tropical Atmosphere Ocean (TAO) array in the Equatorial Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Tropical Atmosphere Ocean (TAO) array of moored buoys spans the tropical Pacific. Moorings within the array measure surface meteorological and upper-ocean...

  12. Sensitivity of decadal predictions to the initial atmospheric and oceanic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Du, H.; Garcia-Serrano, J.; Guemas, V.; Soufflet, Y. [Institut Catala de Ciencies del Clima (IC3), Barcelona (Spain); Doblas-Reyes, F.J. [Institut Catala de Ciencies del Clima (IC3), Barcelona (Spain); Institucio Catalana de Recerca i Estudis Avancats (ICREA), Barcelona (Spain); Wouters, B. [Royal Netherlands Meteorological Institute (KNMI), De Bilt (Netherlands)

    2012-10-15

    A coupled global atmosphere-ocean model is employed to investigate the impact of initial perturbation methods on the behaviour of five-member ensemble decadal re-forecasts. Three initial-condition perturbation strategies, atmosphere only, ocean only and atmosphere-ocean, have been used and the impact on selected variables have been investigated. The impact has been assessed in terms of climate drift, forecast quality and spread. The simulated global means of near-surface air temperature (T2M), sea surface temperature (SST) and sea ice area (SIA) for both Arctic and Antarctic show reasonably good quality, in spite of the non-negligible drift of the model. The skill in terms of correlation is not significantly affected by the particular perturbation method employed. The ensemble spread generated for T2M, SST and land surface precipitation (PCP) saturates quickly with any of the perturbation methods. However, for SIA, Atlantic meridional overturning circulation (AMOC) and ocean heat content (OHC), the spread increases substantially during the forecast time when ocean perturbations are applied. Ocean perturbations are particularly important for Antarctic SIA and OHC for the middle and deep layers of the ocean. The results will be helpful in the design of ensemble prediction experiments. (orig.)

  13. Global Modeling Study of the Bioavailable Atmospheric Iron Supply to the Global Ocean

    Science.gov (United States)

    Myriokefalitakis, S.; Krol, M. C.; van Noije, T.; Le Sager, P.

    2017-12-01

    Atmospheric deposition of trace constituents acts as a nutrient source to the open ocean and affect marine ecosystem. Dust is known as a major source of nutrients to the global ocean, but only a fraction of these nutrients is released in a bioavailable form that can be assimilated by the marine biota. Iron (Fe) is a key micronutrient that significantly modulates gross primary production in the High-Nutrient-Low-Chlorophyll (HNLC) oceans, where macronutrients like nitrate are abundant, but primary production is limited by Fe scarcity. The global atmospheric Fe cycle is here parameterized in the state-of-the-art global Earth System Model EC-Earth. The model takes into account the primary emissions of both insoluble and soluble Fe forms, associated with mineral dust and combustion aerosols. The impact of atmospheric acidity and organic ligands on mineral dissolution processes, is parameterized based on updated experimental and theoretical findings. Model results are also evaluated against available observations. Overall, the link between the labile Fe atmospheric deposition and atmospheric composition changes is here demonstrated and quantified. This work has been financed by the Marie-Curie H2020-MSCA-IF-2015 grant (ID 705652) ODEON (Online DEposition over OceaNs; modeling the effect of air pollution on ocean bio-geochemistry in an Earth System Model).

  14. Coupled Regional Ocean-Atmosphere Modeling of the Mount Pinatubo Impact on the Red Sea

    Science.gov (United States)

    Stenchikov, G. L.; Osipov, S.

    2017-12-01

    The 1991 eruption of Mount Pinatubo had dramatic effects on the regional climate in the Middle East. Though acknowledged, these effects have not been thoroughly studied. To fill this gap and to advance understanding of the mechanisms that control variability in the Middle East's regional climate, we simulated the impact of the 1991 Pinatubo eruption using a regional coupled ocean-atmosphere modeling system set for the Middle East and North Africa (MENA) domain. We used the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) framework, which couples the Weather Research and Forecasting Model (WRF) model with the Regional Oceanic Modeling System (ROMS). We modified the WRF model to account for the radiative effect of volcanic aerosols. Our coupled ocean-atmosphere simulations verified by available observations revealed strong perturbations in the energy balance of the Red Sea, which drove thermal and circulation responses. Our modeling approach allowed us to separate changes in the atmospheric circulation caused by the impact of the volcano from direct regional radiative cooling from volcanic aerosols. The atmospheric circulation effect was significantly stronger than the direct volcanic aerosols effect. We found that the Red Sea response to the Pinatubo eruption was stronger and qualitatively different from that of the global ocean system. Our results suggest that major volcanic eruptions significantly affect the climate in the Middle East and the Red Sea and should be carefully taken into account in assessments of long-term climate variability and warming trends in MENA and the Red Sea.

  15. Setting of cloud albedo in the atmospheric correction procedure to generate the ocean colour data products from OCM-2

    Digital Repository Service at National Institute of Oceanography (India)

    Nagamani, P.V.; Latha, T.P.; Rao, K.H.; Suresh, T.; Choudhury, S.B.; Dutt, C.B.S.; Dadhwal, V.K.

    Cloud masking is one of the primary and important steps in the atmospheric correction procedure in particular to coastal ocean waters. Cloud masking for ocean colour data processing is based on the assumption that the water reflectance is close...

  16. Response of ocean acidification to a gradual increase and decrease of atmospheric CO2

    International Nuclear Information System (INIS)

    Cao, Long; Zhang, Han; Zheng, Meidi; Wang, Shuangjing

    2014-01-01

    We perform coupled climate–carbon cycle model simulations to examine changes in ocean acidity in response to idealized change of atmospheric CO 2 . Atmospheric CO 2 increases at a rate of 1% per year to four times its pre-industrial level of 280 ppm and then decreases at the same rate to the pre-industrial level. Our simulations show that changes in surface ocean chemistry largely follow changes in atmospheric CO 2 . However, changes in deep ocean chemistry in general lag behind the change in atmospheric CO 2 because of the long time scale associated with the penetration of excess CO 2 into the deep ocean. In our simulations with the effect of climate change, when atmospheric CO 2 reaches four times its pre-industrial level, global mean aragonite saturation horizon (ASH) shoals from the pre-industrial value of 1288 to 143 m. When atmospheric CO 2 returns from the peak value of 1120 ppm to pre-industrial level, ASH is 630 m, which is approximately the value of ASH when atmospheric CO 2 first increases to 719 ppm. At pre-industrial CO 2 9% deep-sea cold-water corals are surrounded by seawater that is undersaturated with aragonite. When atmospheric CO 2 reaches 1120 ppm, 73% cold-water coral locations are surrounded by seawater with aragonite undersaturation, and when atmospheric CO 2 returns to the pre-industrial level, 18% cold-water coral locations are surrounded by seawater with aragonite undersaturation. Our analysis indicates the difficulty for some marine ecosystems to recover to their natural chemical habitats even if atmospheric CO 2 content can be lowered in the future. (paper)

  17. Quantifying the drivers of ocean-atmosphere CO2 fluxes

    Science.gov (United States)

    Lauderdale, Jonathan M.; Dutkiewicz, Stephanie; Williams, Richard G.; Follows, Michael J.

    2016-07-01

    A mechanistic framework for quantitatively mapping the regional drivers of air-sea CO2 fluxes at a global scale is developed. The framework evaluates the interplay between (1) surface heat and freshwater fluxes that influence the potential saturated carbon concentration, which depends on changes in sea surface temperature, salinity and alkalinity, (2) a residual, disequilibrium flux influenced by upwelling and entrainment of remineralized carbon- and nutrient-rich waters from the ocean interior, as well as rapid subduction of surface waters, (3) carbon uptake and export by biological activity as both soft tissue and carbonate, and (4) the effect on surface carbon concentrations due to freshwater precipitation or evaporation. In a steady state simulation of a coarse-resolution ocean circulation and biogeochemistry model, the sum of the individually determined components is close to the known total flux of the simulation. The leading order balance, identified in different dynamical regimes, is between the CO2 fluxes driven by surface heat fluxes and a combination of biologically driven carbon uptake and disequilibrium-driven carbon outgassing. The framework is still able to reconstruct simulated fluxes when evaluated using monthly averaged data and takes a form that can be applied consistently in models of different complexity and observations of the ocean. In this way, the framework may reveal differences in the balance of drivers acting across an ensemble of climate model simulations or be applied to an analysis and interpretation of the observed, real-world air-sea flux of CO2.

  18. Estimation of oceanic subsurface mixing under a severe cyclonic storm using a coupled atmosphere-ocean-wave model

    Science.gov (United States)

    Prakash, Kumar Ravi; Nigam, Tanuja; Pant, Vimlesh

    2018-04-01

    A coupled atmosphere-ocean-wave model was used to examine mixing in the upper-oceanic layers under the influence of a very severe cyclonic storm Phailin over the Bay of Bengal (BoB) during 10-14 October 2013. The coupled model was found to improve the sea surface temperature over the uncoupled model. Model simulations highlight the prominent role of cyclone-induced near-inertial oscillations in subsurface mixing up to the thermocline depth. The inertial mixing introduced by the cyclone played a central role in the deepening of the thermocline and mixed layer depth by 40 and 15 m, respectively. For the first time over the BoB, a detailed analysis of inertial oscillation kinetic energy generation, propagation, and dissipation was carried out using an atmosphere-ocean-wave coupled model during a cyclone. A quantitative estimate of kinetic energy in the oceanic water column, its propagation, and its dissipation mechanisms were explained using the coupled atmosphere-ocean-wave model. The large shear generated by the inertial oscillations was found to overcome the stratification and initiate mixing at the base of the mixed layer. Greater mixing was found at the depths where the eddy kinetic diffusivity was large. The baroclinic current, holding a larger fraction of kinetic energy than the barotropic current, weakened rapidly after the passage of the cyclone. The shear induced by inertial oscillations was found to decrease rapidly with increasing depth below the thermocline. The dampening of the mixing process below the thermocline was explained through the enhanced dissipation rate of turbulent kinetic energy upon approaching the thermocline layer. The wave-current interaction and nonlinear wave-wave interaction were found to affect the process of downward mixing and cause the dissipation of inertial oscillations.

  19. National Oceanic and Atmospheric Administration's Cetacean and Sound Mapping Effort: Continuing Forward with an Integrated Ocean Noise Strategy.

    Science.gov (United States)

    Harrison, Jolie; Ferguson, Megan; Gedamke, Jason; Hatch, Leila; Southall, Brandon; Van Parijs, Sofie

    2016-01-01

    To help manage chronic and cumulative impacts of human activities on marine mammals, the National Oceanic and Atmospheric Administration (NOAA) convened two working groups, the Underwater Sound Field Mapping Working Group (SoundMap) and the Cetacean Density and Distribution Mapping Working Group (CetMap), with overarching effort of both groups referred to as CetSound, which (1) mapped the predicted contribution of human sound sources to ocean noise and (2) provided region/time/species-specific cetacean density and distribution maps. Mapping products were presented at a symposium where future priorities were identified, including institutionalization/integration of the CetSound effort within NOAA-wide goals and programs, creation of forums and mechanisms for external input and funding, and expanded outreach/education. NOAA is subsequently developing an ocean noise strategy to articulate noise conservation goals and further identify science and management actions needed to support them.

  20. Ocean-atmosphere dynamics during Hurricane Ida and Nor'Ida: An application of the coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system

    Science.gov (United States)

    Olabarrieta, Maitane; Warner, John C.; Armstrong, Brandy N.; Zambon, Joseph B.; He, Ruoying

    2012-01-01

    The coupled ocean–atmosphere–wave–sediment transport (COAWST) modeling system was used to investigate atmosphere–ocean–wave interactions in November 2009 during Hurricane Ida and its subsequent evolution to Nor’Ida, which was one of the most costly storm systems of the past two decades. One interesting aspect of this event is that it included two unique atmospheric extreme conditions, a hurricane and a nor’easter storm, which developed in regions with different oceanographic characteristics. Our modeled results were compared with several data sources, including GOES satellite infrared data, JASON-1 and JASON-2 altimeter data, CODAR measurements, and wave and tidal information from the National Data Buoy Center (NDBC) and the National Tidal Database. By performing a series of numerical runs, we were able to isolate the effect of the interaction terms between the atmosphere (modeled with Weather Research and Forecasting, the WRF model), the ocean (modeled with Regional Ocean Modeling System (ROMS)), and the wave propagation and generation model (modeled with Simulating Waves Nearshore (SWAN)). Special attention was given to the role of the ocean surface roughness. Three different ocean roughness closure models were analyzed: DGHQ (which is based on wave age), TY2001 (which is based on wave steepness), and OOST (which considers both the effects of wave age and steepness). Including the ocean roughness in the atmospheric module improved the wind intensity estimation and therefore also the wind waves, surface currents, and storm surge amplitude. For example, during the passage of Hurricane Ida through the Gulf of Mexico, the wind speeds were reduced due to wave-induced ocean roughness, resulting in better agreement with the measured winds. During Nor’Ida, including the wave-induced surface roughness changed the form and dimension of the main low pressure cell, affecting the intensity and direction of the winds. The combined wave age- and wave steepness

  1. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from PROFESSOR SIEDLECKI in the Southern Oceans from 1977-01-01 to 1978-12-31 (NODC Accession 9600122)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Serial data in this accession was collected in Southern Oceans (> 60 degrees South) in Polish Antarctic stations as part of Global Ocean Data...

  2. Advancing Atmosphere-Ocean Remote Sensing with Spaceborne High Spectral Resolution Lidar

    Science.gov (United States)

    Hostetler, C. A.; Behrenfeld, M. J.; Chepfer, H.; Hu, Y.; Hair, J. W.; Trepte, C. R.; Winker, D. M.; Ferrare, R. A.; Burton, S. P.; Scarino, A. J.; Powell, K. A.; Michaud, J.

    2016-12-01

    More than 1600 publications employing observations from the CALIOP lidar on CALIPSO testify to the value of spaceborne lidar for aerosol and cloud remote sensing. Recent publications have shown the value of CALIOP data for retrievals of key ocean carbon cycle stocks. In this presentation we focus on the advantages of a more advanced technique, High Spectral Resolution Lidar (HSRL), for aerosol, cloud, and ocean remote sensing. An atmosphere-ocean optimized HSRL achieves greater accuracy over the standard backscatter lidar technique for retrievals of aerosol and cloud extinction and backscatter profiles, provides additional capability to retrieve aerosol and cloud microphysical parameters, and enables vertically-resolved characterization of scattering and absorption properties of suspended and dissolved materials in the ocean. Numerous publications highlight the synergy of coincident CALIOP and passive A-train observations for studies of aerosol-cloud radiative effects and cloud-climate feedback. Less appreciated is the complementarity that would exist between an optimized spaceborne lidar and passive ocean color. An optimized HSRL flown in formation with the Plankton, Aerosol, and ocean Ecosystem (PACE) mission would provide phytoplankton vertical distribution, which is needed for accurately estimating net primary productivity but absent in the PACE ocean color data. The HSRL would also provide data needed to improve atmospheric correction schemes in ocean color retrievals. Because lidar provides measurements both night and day, through tenuous clouds and aerosol layers, and in holes between clouds, the sampling achieved is highly complementary to passive radiometry, providing data in important high latitude regions where ocean color data are sparse or nonexistent. In this presentation we will discuss 1) relevant aerosol, cloud, and ocean retrievals from airborne HSRL field missions; 2) the advantages of an optimized spaceborne HSRL for aerosol, cloud, and ocean

  3. The ocean quasi-homogeneous layer model and global cycle of carbon dioxide in system of atmosphere-ocean

    Science.gov (United States)

    Glushkov, Alexander; Glushkov, Alexander; Loboda, Nataliya; Khokhlov, Valery; Serbov, Nikoly; Svinarenko, Andrey

    The purpose of this paper is carrying out the detailed model of the CO2 global turnover in system of "atmosphere-ocean" with using the ocean quasi-homogeneous layer model. Practically all carried out models are functioning in the average annual regime and accounting for the carbon distribution in bio-sphere in most general form (Glushkov et al, 2003). We construct a modified model for cycle of the carbon dioxide, which allows to reproduce a season dynamics of carbon turnover in ocean with account of zone ocean structure (up quasi-homogeneous layer, thermocline and deepest layer). It is taken into account dependence of the CO2 transfer through the bounder between atmosphere and ocean upon temperature of water and air, wind velocity, buffer mechanism of the CO2 dissolution. The same program is realized for atmosphere part of whole system. It is obtained a tempo-ral and space distribution for concentration of non-organic carbon in ocean, partial press of dissolute CO2 and value of exchange on the border between atmosphere and ocean. It is estimated a role of the wind intermixing of the up ocean layer. The increasing of this effect leads to increasing the plankton mass and further particles, which are transferred by wind, contribute to more quick immersion of microscopic shells and organic material. It is fulfilled investigation of sen-sibility of the master differential equations system solutions from the model parameters. The master differential equa-tions system, describing a dynamics of the CO2 cycle, is numerically integrated by the four order Runge-Cutt method under given initial values of valuables till output of solution on periodic regime. At first it is indicated on possible real-zation of the chaos scenario in system. On our data, the difference of the average annual values for the non-organic car-bon concentration in the up quasi-homogeneous layer between equator and extreme southern zone is 0.15 mol/m3, be-tween the equator and extreme northern zone is 0

  4. Atmospheric delivery of anthropogenic bioavailable iron from mineral dust to the ocean

    OpenAIRE

    伊藤, 彰記; 時, 宗波; ITO, Akinori; SHI, Zongbo

    2015-01-01

    Atmospheric deposition of anthropogenic soluble iron (Fe) to the ocean has been suggested to modulate primary ocean productivity and thus indirectly affect the climate. A key process contributing to anthropogenic sources of soluble Fe is associated with air pollution, which acidifies Fe-containing mineral aerosols during their transport and leads to Fe transformation from insoluble to soluble forms. However, there is large uncertainty in our estimate of this anthropogenic soluble Fe. Here, we...

  5. Out of Thin Air: Microbial Utilization of Atmospheric Gaseous Organics in the Surface Ocean

    KAUST Repository

    Arrieta, J M; Duarte, Carlos M.; Sala, M. Montserrat; Dachs, Jordi

    2016-01-01

    Volatile and semi-volatile gas-phase organic carbon (GOC) is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 and 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidizing marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

  6. Out of Thin Air: Microbial Utilization of Atmospheric Gaseous Organics in the Surface Ocean

    KAUST Repository

    Arrieta, Jesus

    2016-01-20

    Volatile and semi-volatile gas-phase organic carbon (GOC) is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 and 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidizing marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

  7. Simulated effect of calcification feedback on atmospheric CO2 and ocean acidification

    Science.gov (United States)

    Zhang, Han; Cao, Long

    2016-01-01

    Ocean uptake of anthropogenic CO2 reduces pH and saturation state of calcium carbonate materials of seawater, which could reduce the calcification rate of some marine organisms, triggering a negative feedback on the growth of atmospheric CO2. We quantify the effect of this CO2-calcification feedback by conducting a series of Earth system model simulations that incorporate different parameterization schemes describing the dependence of calcification rate on saturation state of CaCO3. In a scenario with SRES A2 CO2 emission until 2100 and zero emission afterwards, by year 3500, in the simulation without CO2-calcification feedback, model projects an accumulated ocean CO2 uptake of 1462 PgC, atmospheric CO2 of 612 ppm, and surface pH of 7.9. Inclusion of CO2-calcification feedback increases ocean CO2 uptake by 9 to 285 PgC, reduces atmospheric CO2 by 4 to 70 ppm, and mitigates the reduction in surface pH by 0.003 to 0.06, depending on the form of parameterization scheme used. It is also found that the effect of CO2-calcification feedback on ocean carbon uptake is comparable and could be much larger than the effect from CO2-induced warming. Our results highlight the potentially important role CO2-calcification feedback plays in ocean carbon cycle and projections of future atmospheric CO2 concentrations. PMID:26838480

  8. Out of Thin Air: Microbial Utilization of Atmospheric Gaseous Organics in the Surface Ocean.

    Science.gov (United States)

    Arrieta, Jesús M; Duarte, Carlos M; Sala, M Montserrat; Dachs, Jordi

    2015-01-01

    Volatile and semi-volatile gas-phase organic carbon (GOC) is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 and 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidizing marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

  9. Out of thin air: Microbial utilization of atmospheric gaseous organics in the surface ocean

    Directory of Open Access Journals (Sweden)

    Jesus M Arrieta

    2016-01-01

    Full Text Available Volatile and semi-volatile gas-phase organic carbon (GOC is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 to 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidising marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

  10. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from PROFESSOR MESYATSYEV, VOZROZHDENIYE and AKADEMIK KNIPOVICH in the North Pacific Ocean, South Atlantic Ocean and South Pacific Ocean from 1973-02-12 to 1990-04-09 (NODC Accession 9600100)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hydrochemical data in this accession was collected as part of Global Ocean Data Archeaology and Rescue (GODAR) project between February 12, 1973 and April 9,...

  11. Geoengineering impact of open ocean dissolution of olivine on atmospheric CO2, surface ocean pH and marine biology

    International Nuclear Information System (INIS)

    Köhler, Peter; Abrams, Jesse F; Völker, Christoph; Hauck, Judith; Wolf-Gladrow, Dieter A

    2013-01-01

    Ongoing global warming induced by anthropogenic emissions has opened the debate as to whether geoengineering is a ‘quick fix’ option. Here we analyse the intended and unintended effects of one specific geoengineering approach, which is enhanced weathering via the open ocean dissolution of the silicate-containing mineral olivine. This approach would not only reduce atmospheric CO 2 and oppose surface ocean acidification, but would also impact on marine biology. If dissolved in the surface ocean, olivine sequesters 0.28 g carbon per g of olivine dissolved, similar to land-based enhanced weathering. Silicic acid input, a byproduct of the olivine dissolution, alters marine biology because silicate is in certain areas the limiting nutrient for diatoms. As a consequence, our model predicts a shift in phytoplankton species composition towards diatoms, altering the biological carbon pumps. Enhanced olivine dissolution, both on land and in the ocean, therefore needs to be considered as ocean fertilization. From dissolution kinetics we calculate that only olivine particles with a grain size of the order of 1 μm sink slowly enough to enable a nearly complete dissolution. The energy consumption for grinding to this small size might reduce the carbon sequestration efficiency by ∼30%. (letter)

  12. Initial conditions and ENSO prediction using a coupled ocean-atmosphere model

    Science.gov (United States)

    Larow, T. E.; Krishnamurti, T. N.

    1998-01-01

    A coupled ocean-atmosphere initialization scheme using Newtonian relaxation has been developed for the Florida State University coupled ocean-atmosphere global general circulation model. The initialization scheme is used to initialize the coupled model for seasonal forecasting the boreal summers of 1987 and 1988. The atmosphere model is a modified version of the Florida State University global spectral model, resolution T-42. The ocean general circulation model consists of a slightly modified version of the Hamburg's climate group model described in Latif (1987) and Latif et al. (1993). The coupling is synchronous with information exchanged every two model hours. Using ECMWF atmospheric daily analysis and observed monthly mean SSTs, two, 1-year, time-dependent, Newtonian relaxation were performed using the coupled model prior to conducting the seasonal forecasts. The coupled initializations were conducted from 1 June 1986 to 1 June 1987 and from 1 June 1987 to 1 June 1988. Newtonian relaxation was applied to the prognostic atmospheric vorticity, divergence, temperature and dew point depression equations. In the ocean model the relaxation was applied to the surface temperature. Two, 10-member ensemble integrations were conducted to examine the impact of the coupled initialization on the seasonal forecasts. The initial conditions used for the ensembles are the ocean's final state after the initialization and the atmospheric initial conditions are ECMWF analysis. Examination of the SST root mean square error and anomaly correlations between observed and forecasted SSTs in the Niño-3 and Niño-4 regions for the 2 seasonal forecasts, show closer agreement between the initialized forecast than two, 10-member non-initialized ensemble forecasts. The main conclusion here is that a single forecast with the coupled initialization outperforms, in SST anomaly prediction, against each of the control forecasts (members of the ensemble) which do not include such an initialization

  13. Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations. Part I: Surface fluxes

    Science.gov (United States)

    Josse, P.; Caniaux, G.; Giordani, H.; Planton, S.

    1999-04-01

    A mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer to the atmosphere is

  14. South African carbon observations: CO2 measurements for land, atmosphere and ocean

    CSIR Research Space (South Africa)

    Feig, Gregor T

    2017-11-01

    Full Text Available , Mudau AE, Monteiro PMS. South African carbon observations: CO2 measurements for land, atmosphere and ocean. S Afr J Sci. 2017;113(11/12), Art. #a0237, 4 pages. http://dx.doi. org/10.17159/sajs.2017/a0237 Carbon dioxide plays a central role in earth... References 1. Houghton RA. Balancing the global carbon budget. Annu Rev Earth Planet Sci. 2007;35:313–347. https://doi.org/10.1146/annurev. earth.35.031306.140057 2. Denman KL. Climate change, ocean processes and ocean iron fertilization. Mar Ecol Prog Ser...

  15. Remote sensing for global change, climate change and atmosphere and ocean forecasting. Volume 1

    International Nuclear Information System (INIS)

    1992-01-01

    This volume is separated in three sessions. First part is on remote sensing for global change (with global modelling, land cover change on global scale, ocean colour studies of marine biosphere, biological and hydrological interactions and large scale experiments). Second part is on remote sensing for climate change (with earth radiation and clouds, sea ice, global climate research programme). Third part is on remote sensing for atmosphere and ocean forecasting (with temperatures and humidity, winds, data assimilation, cloud imagery, sea surface temperature, ocean waves and topography). (A.B.). refs., figs., tabs

  16. Climate-driven changes to the atmospheric CO2 sink in the subtropical North Pacific Ocean.

    Science.gov (United States)

    Dore, John E; Lukas, Roger; Sadler, Daniel W; Karl, David M

    2003-08-14

    The oceans represent a significant sink for atmospheric carbon dioxide. Variability in the strength of this sink occurs on interannual timescales, as a result of regional and basin-scale changes in the physical and biological parameters that control the flux of this greenhouse gas into and out of the surface mixed layer. Here we analyse a 13-year time series of oceanic carbon dioxide measurements from station ALOHA in the subtropical North Pacific Ocean near Hawaii, and find a significant decrease in the strength of the carbon dioxide sink over the period 1989-2001. We show that much of this reduction in sink strength can be attributed to an increase in the partial pressure of surface ocean carbon dioxide caused by excess evaporation and the accompanying concentration of solutes in the water mass. Our results suggest that carbon dioxide uptake by ocean waters can be strongly influenced by changes in regional precipitation and evaporation patterns brought on by climate variability.

  17. Estimation of the atmosphere-ocean fluxes of greenhouse gases and aerosols at the finer resolution of the coastal ocean.

    Science.gov (United States)

    Vieira, Vasco; Sahlée, Erik; Jurus, Pavel; Clementi, Emanuela; Pettersson, Heidi; Mateus, Marcos

    2016-04-01

    The balances and fluxes of greenhouse gases and aerosols between atmosphere and ocean are fundamental for Earth's heat budget. Hence, the scientific community needs to know and simulate them with accuracy in order to monitor climate change from Earth-Observation satellites and to produce reliable estimates of climate change using Earth-System Models (ESM). So far, ESM have represented earth's surface with coarser resolutions so that each cell of the marine domain is dominated by the open ocean. In such case it is enough to use simple algorithms considering the wind speed 10m above sea-surface (u10) as sole driver of the gas transfer velocity. The formulation by Wanninkhof (1992) is broadly accepted as the best. However, the ESM community is becoming increasingly aware of the need to model with finer resolutions. Then, it is no longer enough to only consider u10 when modelling gas transfer velocities across the coastal oceans' surfaces. More comprehensive formulations are required that adjust better to local conditions by also accounting for the effects of sea-surface agitation, wave breaking, atmospheric stability of the Surface Boundary Layer, current drag with the bottom, surfactants and rain. Accurate algorithms are also fundamental to monitor atmosphere and ocean greenhouse gas concentrations using satellite data and reverse modelling. Past satellite missions ERS, Envisat, Jason-2, Aqua, Terra and Metop, have already been remotely sensing the ocean's surface at much finer resolutions than ESM using instruments like MERIS, MODIS, AMR, AATSR, MIPAS, Poseidon-3, SCIAMACHY, SeaWiFS, and IASI. The planned new satellite missions Sentinel-3, OCO-2 and GOSAT will further increase the resolutions. We developed a framework to congregate competing formulations for the estimation of the solubility and transfer velocity of virtually any gas on the biosphere taking into consideration the atmosphere and ocean fundamental variables and their derived geophysical processes

  18. Development of the OASIS acquisition system

    International Nuclear Information System (INIS)

    Douet, R.

    1999-01-01

    OASIS is a general purpose data acquisition system built at IPN Orsay, which has been developed around UNIX and VME real time processors. This system can be used to acquire, process, store and display physics data. New OASIS is also used to process event data tapes coming from experiments and has been connected to the analysis software at IPN. (author)

  19. Tracing Carbon Cycling in the Atmosphere and Oceans During the Cretaceous Ocean Anoxic Event 2 (OAE2, 94Ma)

    Science.gov (United States)

    Moran, S. A. M.; Boudinot, F. G.; Dildar, N.; Sepúlveda, J.

    2017-12-01

    We present a high-resolution record of compound-specific stable carbon isotope data from short-chain—aquatic algae—and long-chain n-alkanes—terrestrial plants—preserved in sedimentary sequences from the Smokey Hollow #1 (SH1) core in the Grand Staircase Escalante National Monument in southern Utah. The study area covered by SH1 core was situated at the western margin of the Western Interior Seaway during the Cretaceous Ocean Anoxic Event (OAE2, 94Ma.), and was characterized by high sedimentation rates and enhanced preservation of both marine and terrestrial organic matter. Short- and long-chain n-alkanes were isolated and purified from branched and cyclic aliphatic hydrocarbons using an optimized urea adduction protocol, and δ13Cn-alkane was measured using a Thermo MAT253 GC-C-IR-MS. We use the δ13Cn-alkane from aquatic and terrestrial sources to better understand carbon cycle interactions in the oceanic and atmospheric carbon pools across this event. Our results indicate that the δ13C of terrestrial plants experienced a faster and more pronounced positive carbon isotope excursion compared to marine sources. We will discuss how these results can inform models of carbon cycle interactions between the ocean and the atmosphere during greenhouse climates, and how they can be used to trace possible sources of CO2.

  20. Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations Part I: Surface fluxes

    Directory of Open Access Journals (Sweden)

    P. Josse

    1999-04-01

    Full Text Available A mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer

  1. Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations Part I: Surface fluxes

    Directory of Open Access Journals (Sweden)

    H. Giordani

    Full Text Available A mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer

  2. Uncertainty in the ocean-atmosphere feedbacks associated with ENSO in the reanalysis products

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Arun; Hu, Zeng-Zhen [NCEP/NWS/NOAA, Climate Prediction Center, Camp Springs, MD (United States)

    2012-08-15

    The evolution of El Nino-Southern Oscillation (ENSO) variability can be characterized by various ocean-atmosphere feedbacks, for example, the influence of ENSO related sea surface temperature (SST) variability on the low-level wind and surface heat fluxes in the equatorial tropical Pacific, which in turn affects the evolution of the SST. An analysis of these feedbacks requires physically consistent observational data sets. Availability of various reanalysis data sets produced during the last 15 years provides such an opportunity. A consolidated estimate of ocean surface fluxes based on multiple reanalyses also helps understand biases in ENSO predictions and simulations from climate models. In this paper, the intensity and the spatial structure of ocean-atmosphere feedback terms (precipitation, surface wind stress, and ocean surface heat flux) associated with ENSO are evaluated for six different reanalysis products. The analysis provides an estimate for the feedback terms that could be used for model validation studies. The analysis includes the robustness of the estimate across different reanalyses. Results show that one of the ''coupled'' reanalysis among the six investigated is closer to the ensemble mean of the results, suggesting that the coupled data assimilation may have the potential to better capture the overall atmosphere-ocean feedback processes associated with ENSO than the uncoupled ones. (orig.)

  3. Matrix formulations of radiative transfer including the polarization effect in a coupled atmosphere-ocean system

    International Nuclear Information System (INIS)

    Ota, Yoshifumi; Higurashi, Akiko; Nakajima, Teruyuki; Yokota, Tatsuya

    2010-01-01

    A vector radiative transfer model has been developed for a coupled atmosphere-ocean system. The radiative transfer scheme is based on the discrete ordinate and matrix operator methods. The reflection/transmission matrices and source vectors are obtained for each atmospheric or oceanic layer through the discrete ordinate solution. The vertically inhomogeneous system is constructed using the matrix operator method, which combines the radiative interaction between the layers. This radiative transfer scheme is flexible for a vertically inhomogeneous system including the oceanic layers as well as the ocean surface. Compared with the benchmark results, the computational error attributable to the radiative transfer scheme has been less than 0.1% in the case of eight discrete ordinate directions. Furthermore, increasing the number of discrete ordinate directions has produced computations with higher accuracy. Based on our radiative transfer scheme, simulations of sun glint radiation have been presented for wavelengths of 670 nm and 1.6 μm. Results of simulations have shown reasonable characteristics of the sun glint radiation such as the strongly peaked, but slightly smoothed radiation by the rough ocean surface and depolarization through multiple scattering by the aerosol-loaded atmosphere. The radiative transfer scheme of this paper has been implemented to the numerical model named Pstar as one of the OpenCLASTR/STAR radiative transfer code systems, which are widely applied to many radiative transfer problems, including the polarization effect.

  4. Geographical Distribution and Sources of Nutrients in Atmospheric Aerosol Over the Pacific Ocean

    Science.gov (United States)

    Uematsu, M.

    2016-12-01

    The Pacific Ocean, the world's largest (occupying about 30% of the Earth's total surface area) has several distinguishing biogeochemical features. In the western Pacific, dust particles originating from arid and semi-arid regions in Asia and Australia are transported to the north and south, respectively. Biomass burning emissions from Southeast Asia are exported to the tropical Pacific, and anthropogenic substances flowing out of Asia and Eurasia spread both regionally and globally. Over high primary productive areas such as the subarctic North Pacific, the equatorial Pacific and the Southern Ocean, biogenic gasses are released to the atmosphere and transported to other areas. These processes may affect cloud and rainfall patterns, air quality, and the radiative balance of downwind regions. The deposition of atmospheric aerosols containing iron and other essential nutrients is important for biogeochemical cycles in the oceans because this source of nutrients helps sustain primary production and affects food-web structure; these effects in turn influence the chemical properties of marine atmosphere. From an atmospheric chemistry standpoint, sea-salt aerosols produced by strong winds and marine biogenic gases emitted from highly productive waters affect the physicochemical characteristics of marine aerosols. As phytoplankton populations are patchy and atmospheric processes sporadic, the interactions between atmospheric chemical constituents and marine biota vary for different regions as well as seasonally and over longer timescales. To address these and other emerging issues, and more generally to better understand the important biogeochemical processes and interactions occurring over the open oceans, more long-term recurrent research cruises with standardized atmospheric shipboard measurements will be needed in the future.

  5. Earth orientation and its excitations by atmosphere, oceans, and geomagnetic jerks

    Directory of Open Access Journals (Sweden)

    Vondrák J.

    2015-01-01

    Full Text Available In addition to torques exerted by the Moon, Sun, and planets, changes of the Earth orientation parameters (EOP are known to be caused also by excitations by the atmosphere and oceans. Recently appeared studies, hinting that geomagnetic jerks (GMJ, rapid changes of geomagnetic field might be associated with sudden changes of phase and amplitude of EOP (Holme and de Viron 2005, 2013, Gibert and Le Mouёl 2008, Malkin 2013. We (Ron et al. 2015 used additional excitations applied at the epochs of GMJ to derive its influence on motion of the spin axis of the Earth in space (precession-nutation. We demonstrated that this effect, if combined with the influence of the atmosphere and oceans, improves substantially the agreement with celestial pole offsets observed by Very Long-Baseline Interferometry. Here we concentrate our efforts to study possible influence of GMJ on temporal changes of all five Earth orientation parameters defining the complete Earth orientation in space. Numerical integration of Brzeziński's broad-band Liouville equations (Brzeziński 1994 with atmospheric and oceanic excitations, combined with expected GMJ effects, is used to derive EOP and compare them with their observed values. We demonstrate that the agreement between all five Earth orientation parameters integrated by this method and those observed by space geodesy is improved substantially if the influence of additional excitations at GMJ epochs is added to excitations by the atmosphere and oceans.

  6. Earth Orientation and Its Excitations by Atmosphere, Oceans, and Geomagnetic Jerks

    Science.gov (United States)

    Vondrák, J.; Ron, C.

    2015-12-01

    In addition to torques exerted by the Moon, Sun, and planets, changes of the Earth orientation parameters (EOP) are known to be caused also by excitations by the atmosphere and oceans. Recently appeared studies, hinting that geomagnetic jerks (GMJ, rapid changes of geomagnetic field) might be associated with sudden changes of phase and amplitude of EOP (Holme and de Viron 2005, 2013, Gibert and Le Mouël 2008, Malkin 2013). We (Ron et al. 2015) used additional excitations applied at the epochs of GMJ to derive its influence on motion of the spin axis of the Earth in space (precession-nutation). We demonstrated that this effect, if combined with the influence of the atmosphere and oceans, improves substantially the agreement with celestial pole offsets observed by Very Long-Baseline Interferometry. Here we concentrate our efforts to study possible influence of GMJ on temporal changes of all five Earth orientation parameters defining the complete Earth orientation in space. Numerical integration of Brzeziński's broad-band Liouville equations (Brzeziński 1994) with atmospheric and oceanic excitations, combined with expected GMJ effects, is used to derive EOP and compare them with their observed values. We demonstrate that the agreement between all five Earth orientation parameters integrated by this method and those observed by space geodesy is improved substantially if the influence of additional excitations at GMJ epochs is added to excitations by the atmosphere and oceans.

  7. The heat and moisture budgets of the atmosphere over central equatorial Indian Ocean during summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Gopalakrishna, V.V.; RameshBabu, V.; Sastry, J.S.

    The heat and moisture budgets of the atmosphere (surface to 100 mb) over the central equatorial Indian Ocean (2 degrees N to 2 degrees S; 76 degrees E to 80 degrees E) have been investigated utilising the surface and upper air data collected...

  8. Radiative transfer modeling through terrestrial atmosphere and ocean accounting for inelastic processes: Software package SCIATRAN

    Science.gov (United States)

    Rozanov, V. V.; Dinter, T.; Rozanov, A. V.; Wolanin, A.; Bracher, A.; Burrows, J. P.

    2017-06-01

    SCIATRAN is a comprehensive software package which is designed to model radiative transfer processes in the terrestrial atmosphere and ocean in the spectral range from the ultraviolet to the thermal infrared (0.18-40 μm). It accounts for multiple scattering processes, polarization, thermal emission and ocean-atmosphere coupling. The main goal of this paper is to present a recently developed version of SCIATRAN which takes into account accurately inelastic radiative processes in both the atmosphere and the ocean. In the scalar version of the coupled ocean-atmosphere radiative transfer solver presented by Rozanov et al. [61] we have implemented the simulation of the rotational Raman scattering, vibrational Raman scattering, chlorophyll and colored dissolved organic matter fluorescence. In this paper we discuss and explain the numerical methods used in SCIATRAN to solve the scalar radiative transfer equation including trans-spectral processes, and demonstrate how some selected radiative transfer problems are solved using the SCIATRAN package. In addition we present selected comparisons of SCIATRAN simulations with those published benchmark results, independent radiative transfer models, and various measurements from satellite, ground-based, and ship-borne instruments. The extended SCIATRAN software package along with a detailed User's Guide is made available for scientists and students, who are undertaking their own research typically at universities, via the web page of the Institute of Environmental Physics (IUP), University of Bremen: http://www.iup.physik.uni-bremen.de.

  9. A reevaluation of the magnitude and impacts of anthropogenic atmospheric nitrogen inputs on the ocean

    NARCIS (Netherlands)

    Jickells, T.D.; Buitenhuis, E.; Altieri, K.; Baker, A.R.; Capone, D.; Duce, R.A.; Dentener, Frank; Fennel, F.; Kanakidou, M.; LaRoche, J.; Lee, K.; Liss, P.; Middelburg, Jack J.|info:eu-repo/dai/nl/079665373; Moore, J.K.; Okin, G.; Oschlies, A.; Sarin, M.; Seitzinger, S.; Sharples, J.; Singh, A.; Suntharalingam, P.; Uematsu, M.; Zamora, L.M.

    We report a new synthesis of best estimates of the inputs of fixed nitrogen to the world ocean via atmospheric deposition and compare this to fluvial inputs and dinitrogen fixation. We evaluate the scale of human perturbation of these fluxes. Fluvial inputs dominate inputs to the continental shelf,

  10. Regional contributions of ocean iron fertilization to atmospheric CO2 changes during the last glacial termination

    Science.gov (United States)

    Opazo, N. E.; Lambert, F.

    2017-12-01

    Mineral dust aerosols affect climate directly by changing the radiative balance of the Earth, and indirectly by acting as cloud condensation nuclei and by affecting biogeochemical cycles. The impact on marine biogeochemical cycles is primarily through the supply of micronutrients such as iron to nutrient-limited regions of the oceans. Iron fertilization of High Nutrient Low Chlorophyll (HNLC) regions of the oceans is thought to have significantly affected the carbon cycle on glacial-interglacial scales and contributed about one fourth of the 80-100 ppm lowering of glacial atmospheric CO2 concentrations.In this study, we quantify the effect of global dust fluxes on atmospheric CO2 using the cGENIE model, an Earth System Model of Intermediate Complexity with emphasis on the carbon cycle. Global Holocene and Last Glacial Maximum (LGM) dust flux fields were obtained from both dust model simulations and reconstructions based on observational data. The analysis was performed in two stages. In the first instance, we produced 8 global intermediate dust flux fields between Holocene and LGM and simulated the atmospheric CO2 drawdown due to these 10 dust levels. In the second stage, we only changed dust flux levels in specific HNLC regions to isolate the effect of these ocean basins. We thus quantify the contribution of the South Atlantic, the South Pacific, the North Pacific, and the Central Pacific HNLC regions to the total atmospheric CO2 difference due to iron fertilization of the Earth's oceans.

  11. Atmospheric Wind Relaxations and the Oceanic Response in the California Current Large Marine Ecosystem

    Science.gov (United States)

    Fewings, M. R.; Dorman, C. E.; Washburn, L.; Liu, W.

    2010-12-01

    On the West Coast of North America in summer, episodic relaxation of the upwelling-favorable winds causes warm water to propagate northward from southern to central California, against the prevailing currents [Harms and Winant 1998, Winant et al. 2003, Melton et al. 2009]. Similar wind relaxations are an important characteristic of coastal upwelling ecosystems worldwide. Although these wind relaxations have an important influence on coastal ocean dynamics, no description exists of the regional atmospheric patterns that lead to wind relaxations in southern California, or of the regional ocean response. We use QuikSCAT wind stress, North American Regional Reanalysis atmospheric pressure products, water temperature and velocity from coastal ocean moorings, surface ocean currents from high-frequency radars, and MODIS satellite sea-surface temperature and ocean color images to analyze wind relaxation events and the ocean response. We identify the events based on an empirical index calculated from NDBC buoy winds [Melton et al. 2009]. We describe the regional evolution of the atmosphere from the Gulf of Alaska to Baja California over the few days leading up to wind relaxations, and the coastal ocean temperature, color, and current response off southern and central California. We analyze ~100 wind relaxation events in June-September during the QuikSCAT mission, 1999-2009. Our results indicate south-central California wind relaxations in summer are tied to mid-level atmospheric low-pressure systems that form in the Gulf of Alaska and propagate southeastward over 3-5 days. As the low-pressure systems reach southern California, the atmospheric pressure gradient along the coast weakens, causing the surface wind stress to relax to near zero. The weak wind signal appears first at San Diego and propagates northward. QuikSCAT data indicate the relaxed winds extend over the entire Southern California Bight and up to 200 km offshore of central California. Atmospheric dynamics in

  12. The atmospheric wet pool: definition and comparison with the oceanic warm pool

    Institute of Scientific and Technical Information of China (English)

    ZHANG Caiyun; CHEN Ge

    2008-01-01

    The oceanic warm pool (OWP) defined by sea surface temperature (SST) is known as the "heat reservoir" in the ocean. The warmest portion in the ocean mirrors the fact that the wettest region with the largest accumulation of water vapor (WV) in the atmosphere, termed atmospheric wet pool (AWP), should be identified because of the well-known Clausius-Clapeyron relationship between SST and WV. In this study, we used 14-year simultaneous observations of WV and SST from January 1988 to December 2001 to define the AWP and investigate its coupling and co-variations with the OWP. The joint examination of the area variations, centroid locations, and zonal migrations of the AWP and OWP lead to a number of interesting findings. The results hopefully can contribute to our understanding of the air-sea interaction in general and characterization of El Nifio/La Nina events in particular.

  13. Radiative transfer solutions for coupled atmosphere ocean systems using the matrix operator technique

    International Nuclear Information System (INIS)

    Hollstein, André; Fischer, Jürgen

    2012-01-01

    Accurate radiative transfer models are the key tools for the understanding of radiative transfer processes in the atmosphere and ocean, and for the development of remote sensing algorithms. The widely used scalar approximation of radiative transfer can lead to errors in calculated top of atmosphere radiances. We show results with errors in the order of±8% for atmosphere ocean systems with case one waters. Variations in sea water salinity and temperature can lead to variations in the signal of similar magnitude. Therefore, we enhanced our scalar radiative transfer model MOMO, which is in use at Freie Universität Berlin, to treat these effects as accurately as possible. We describe our one-dimensional vector radiative transfer model for an atmosphere ocean system with a rough interface. We describe the matrix operator scheme and the bio-optical model for case one waters. We discuss some effects of neglecting polarization in radiative transfer calculations and effects of salinity changes for top of atmosphere radiances. Results are shown for the channels of the satellite instruments MERIS and OLCI from 412.5 nm to 900 nm.

  14. Estimation of the Ocean Skin Temperature using the NASA GEOS Atmospheric Data Assimilation System

    Science.gov (United States)

    Koster, Randal D.; Akella, Santha; Todling, Ricardo; Suarez, Max

    2016-01-01

    This report documents the status of the development of a sea surface temperature (SST) analysis for the Goddard Earth Observing System (GEOS) Version-5 atmospheric data assimilation system (ADAS). Its implementation is part of the steps being taken toward the development of an integrated earth system analysis. Currently, GEOS-ADAS SST is a bulk ocean temperature (from ocean boundary conditions), and is almost identical to the skin sea surface temperature. Here we describe changes to the atmosphere-ocean interface layer of the GEOS-atmospheric general circulation model (AGCM) to include near surface diurnal warming and cool-skin effects. We also added SST relevant Advanced Very High Resolution Radiometer (AVHRR) observations to the GEOS-ADAS observing system. We provide a detailed description of our analysis of these observations, along with the modifications to the interface between the GEOS atmospheric general circulation model, gridpoint statistical interpolation-based atmospheric analysis and the community radiative transfer model. Our experiments (with and without these changes) show improved assimilation of satellite radiance observations. We obtained a closer fit to withheld, in-situ buoys measuring near-surface SST. Evaluation of forecast skill scores corroborate improvements seen in the observation fits. Along with a discussion of our results, we also include directions for future work.

  15. Novel Atmospheric and Sea State Modeling in Ocean Energy Applications

    Science.gov (United States)

    Kallos, George; Galanis, George; Kalogeri, Christina; Larsen, Xiaoli Guo

    2013-04-01

    The rapidly increasing use of renewable energy sources poses new challenges for the research and technological community today. The integration of the, usually, highly variable wind and wave energy amounts into the general grid, the optimization of energy transition and the forecast of extreme values that could lead to instabilities and failures of the system can be listed among them. In the present work, novel methodologies based on state of the art numerical wind/wave simulation systems and advanced statistical techniques addressing such type of problems are discussed. In particular, extremely high resolution modeling systems simulating the atmospheric and sea state conditions with spatial resolution of 100 meters or less and temporal discretization of a few seconds are utilized in order to simulate in the most detailed way the combined wind-wave energy potential at offshore sites. In addition, a statistical analysis based on a variety of mean and variation measures as well as univariate and bivariate probability distributions is used for the estimation of the variability of the power potential revealing the advantages of the use of combined forms of energy by offshore platforms able to produce wind and wave power simultaneously. The estimation and prediction of extreme wind/wave conditions - a critical issue both for site assessment and infrastructure maintenance - is also studied by means of the 50-year return period over areas with increased power potential. This work has been carried out within the framework of the FP7 project MARINA Platform (http://www.marina-platform.info/index.aspx).

  16. Using an atmospheric boundary layer model to force global ocean models

    Science.gov (United States)

    Abel, Rafael; Böning, Claus

    2014-05-01

    Current practices in the atmospheric forcing of ocean model simulations can lead to unphysical behaviours. The problem lies in the bulk formulation of the turbulent air-sea fluxes in the conjunction with a prescribed, and unresponsive, atmospheric state (as given by reanalysis products). This can have impacts both on mesoscale processes as well as on the dynamics of the large-scale circulation. First, a possible local mismatch between the given atmospheric state and evolving sea surface temperature (SST) signatures can occur, especially for mesoscale features such as frontal areas, eddies, or near the sea ice edge. Any ocean front shift or evolution of mesoscale anomalies results in excessive, unrealistic surface fluxes due to the lack of atmospheric adaptation. Second, a subtle distortion in the sensitive balance of feedback processes being critical for the thermohaline circulation. Since the bulk formulations assume an infinite atmospheric heat capacity, resulting SST anomalies are strongly damped even on basin-scales (e.g. from trends in the Atlantic meridional overturning circulation). In consequence, an important negative feedback is eliminated, rendering the system excessively susceptible to small anomalies (or errors) in the freshwater fluxes. Previous studies (Seager et al., 1995, J. Clim.) have suggested a partial forcing issue remedy that aimed for a physically more realistic determination of air-sea fluxes by allowing some (thermodynamic) adaptation of the atmospheric boundary layer to SST changes. In this study a modernized formulation of this approach (Deremble et al., 2013, Mon. Weather Rev.; 'CheapAML') is implemented in a global ocean-ice model with moderate resolution (0.5°; ORCA05). In a set of experiments we explore the solution behaviour of this forcing approach (where only the winds are prescribed, while atmospheric temperature and humidity are computed), contrasting it with the solution obtained from the classical bulk formulation with a non

  17. Sea level variability in the eastern tropical Pacific as observed by TOPEX and Tropical Ocean-Global Atmosphere Tropical Atmosphere-Ocean Experiment

    Science.gov (United States)

    Giese, Benjamin S.; Carton, James A.; Holl, Lydia J.

    1994-01-01

    Sea surface height measurements from the TOPEX altimeter and dynamic height from Tropical Ocean-Global Atmosphere Tropical Atmosphere-Ocean (TOGA TAO) moorings are used to explore sea level variability in the northeastern tropical Pacific Ocean. Afetr the annual harmonic is removed, there are two distinct bands of variability: one band is centered at 5 deg N to 7 deg N and extends from 165 deg W to 110 deg W, and the other band is centered at 10 deg N to 12 deg N and extends from 120 deg W to the coast of Central America. The correspondence between the two independent observation data sets at 5 deg N is excellent with correlations of about 90%. The variability at 5 deg-7 deg N is identified as instability waves formed just south of the North Equatorial Countercurrent during the months of July and March. Wave amplitudes are largest in the range of longitudes 160 deg-140 deg W, where they can exceed 10 cm. The waves disappear when the equatorial current system weakens, during the months of March and May. The variability at 11 deg N in 1993 has the form of anticyclone eddies. These eddies propagate westward at a speed of about 17 cm/s, consistent with the dispersion characteristics of free Rossby waves. The eddies are shown to have their origin near the coast of central America during northern fall and winter. Their formation seems to result from intense wind bursts across the Gulfs of Tehuantepec and Papagayo which generate strong anticyclonic ocean eddies. The disappearance of the eddies in the summer of 1993 coincidences with the seasonal intensification of equatorial currents. Thus the variability at 11 deg N has very little overlap in time with the variability at 5 deg N.

  18. Nitrogen and Triple Oxygen Isotopic Analyses of Atmospheric Particulate Nitrate over the Pacific Ocean

    Science.gov (United States)

    Kamezaki, Kazuki; Hattori, Shohei; Iwamoto, Yoko; Ishino, Sakiko; Furutani, Hiroshi; Miki, Yusuke; Miura, Kazuhiko; Uematsu, Mitsuo; Yoshida, Naohiro

    2017-04-01

    Nitrate plays a significant role in the biogeochemical cycle. Atmospheric nitrate (NO3- and HNO3) are produced by reaction precursor as NOx (NO and NO2) emitted by combustion, biomass burning, lightning, and soil emission, with atmospheric oxidants like ozone (O3), hydroxyl radical (OH), peroxy radical and halogen oxides. Recently, industrial activity lead to increases in the concentrations of nitrogen species (NOx and NHy) throughout the environment. Because of the increase of the amount of atmospheric nitrogen deposition, the oceanic biogeochemical cycle are changed (Galloway et al., 2004; Kim et al., 2011). However, the sources and formation pathways of atmospheric nitrate are still uncertain over the Pacific Ocean because the long-term observation is limited. Stable isotope analysis is useful tool to gain information of sources, sinks and formation pathways. The nitrogen stable isotopic composition (δ15N) of atmospheric particulate NO3- can be used to posses information of its nitrogen sources (Elliott et al., 2007). Triple oxygen isotopic compositions (Δ17O = δ17O - 0.52 ×δ18O) of atmospheric particulate NO3- can be used as tracer of the relative importance of mass-independent oxygen bearing species (e.g. O3, BrO; Δ17O ≠ 0 ‰) and mass-dependent oxygen bearing species (e.g. OH radical; Δ17O ≈ 0 ‰) through the formation processes from NOx to NO3- in the atmosphere (Michalski et al., 2003; Thiemens, 2006). Here, we present the isotopic compositions of atmospheric particulate NO3- samples collected over the Pacific Ocean from 40˚ S to 68˚ N. We observed significantly low δ15N values for atmospheric particulate NO3- on equatorial Pacific Ocean during both cruises. Although the data is limited, combination analysis of δ15N and Δ17O values for atmospheric particulate NO3- showed the possibility of the main nitrogen source of atmospheric particulate NO3- on equatorial Pacific Ocean is ammonia oxidation in troposphere. Furthermore, the Δ17O values

  19. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from XIANG YANG HONG 05 and SHI YAN 3 in the Philippine Sea, Indian Ocean and South Pacific Ocean from 1991-11-01 to 1993-11-30 (NODC Accession 9400186)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Conductivity, Temperature and Depth (CTD) and other data were collected as part of the Coupled Ocean Atmosphere Response Experiment. Data were collected from Ships...

  20. PBDEs in the atmosphere over the Asian marginal seas, and the Indian and Atlantic oceans

    Science.gov (United States)

    Li, Jun; Li, Qilu; Gioia, Rosalinda; Zhang, Yanlin; Zhang, Gan; Li, Xiangdong; Spiro, Baruch; Bhatia, Ravinder S.; Jones, Kevin C.

    2011-12-01

    Air samples were collected from Jan 16 to Mar 14, 2008 onboard the Oceanic II- The Scholar Ship which navigated an east-west transect from Shanghai to Cape Verde, and polybrominated diphenyl ethers (PBDEs) were analyzed in these samples. PBDE concentrations in the atmosphere over the open seas were influenced by proximity to source areas and land, and air mass origins. The concentrations of Σ 21PBDEs over the East and South China Seas, the Bay of Bengal and the Andaman Sea, the Indian Ocean, and the Atlantic Ocean were 10.8 ± 6.13, 3.22 ± 1.57, 5.12 ± 3.56, and 2.87 ± 1.81 pg m -3, respectively. BDE-47 and -99 were the dominant congeners in all the samples, suggesting that the widely used commercial penta-BDE products were the original sources. Over some parts of Atlantic and Indian Ocean, daytime concentrations of BDE-47 and BDE-99 were higher than the concentrations at night. The strong atmospheric variability does not always coincide with a diurnal cycle, but the variability in air concentrations in such remote areas of the ocean remains strong. No significant trends were found for each of PBDE congener with latitude.

  1. Atmosphere-Ocean Variations in the Indo-Pacific Sector during ENSO Episodes.

    Science.gov (United States)

    Lau, Ngar-Cheung; Nath, Mary Jo

    2003-01-01

    The influences of El Niño-Southern Oscillation (ENSO) events on air-sea interaction in the Indian-western Pacific (IWP) Oceans have been investigated using a general circulation model. Observed monthly sea surface temperature (SST) variations in the deep tropical eastern/central Pacific (DTEP) have been inserted in the lower boundary of this model through the 1950-99 period. At all maritime grid points outside of DTEP, the model atmosphere has been coupled with an oceanic mixed layer model with variable depth. Altogether 16 independent model runs have been conducted.Composite analysis of selected ENSO episodes illustrates that the prescribed SST anomalies in DTEP affect the surface atmospheric circulation and precipitation patterns in IWP through displacements of the near-equatorial Walker circulation and generation of Rossby wave modes in the subtropics. Such atmospheric responses modulate the surface fluxes as well as the oceanic mixed layer depth, and thereby establish a well-defined SST anomaly pattern in the IWP sector several months after the peak in ENSO forcing in DTEP. In most parts of the IWP region, the net SST tendency induced by atmospheric changes has the same polarity as the local composite SST anomaly, thus indicating that the atmospheric forcing acts to reinforce the underlying SST signal.By analyzing the output from a suite of auxiliary experiments, it is demonstrated that the SST perturbations in IWP (which are primarily generated by ENSO-related atmospheric changes) can, in turn, exert notable influences on the atmospheric conditions over that region. This feedback mechanism also plays an important role in the eastward migration of the subtropical anticyclones over the western Pacific in both hemispheres.

  2. Pleistocene atmospheric CO2 change linked to Southern Ocean nutrient utilization

    Science.gov (United States)

    Ziegler, M.; Diz, P.; Hall, I. R.; Zahn, R.

    2011-12-01

    Biological uptake of CO2 by the ocean and its subsequent storage in the abyss is intimately linked with the global carbon cycle and constitutes a significant climatic force1. The Southern Ocean is a particularly important region because its wind-driven upwelling regime brings CO2 laden abyssal waters to the surface that exchange CO2 with the atmosphere. The Subantarctic Zone (SAZ) is a CO2 sink and also drives global primary productivity as unutilized nutrients, advected with surface waters from the south, are exported via Subantarctic Mode Water (SAMW) as preformed nutrients to the low latitudes where they fuel the biological pump in upwelling areas. Recent model estimates suggest that up to 40 ppm of the total 100 ppm atmospheric pCO2 reduction during the last ice age were driven by increased nutrient utilization in the SAZ and associated feedbacks on the deep ocean alkalinity. Micro-nutrient fertilization by iron (Fe), contained in the airborne dust flux to the SAZ, is considered to be the prime factor that stimulated this elevated photosynthetic activity thus enhancing nutrient utilization. We present a millennial-scale record of the vertical stable carbon isotope gradient between subsurface and deep water (Δδ13C) in the SAZ spanning the past 350,000 years. The Δδ13C gradient, derived from planktonic and benthic foraminifera, reflects the efficiency of biological pump and is highly correlated (rxy = -0.67 with 95% confidence interval [0.63; 0.71], n=874) with the record of dust flux preserved in Antarctic ice cores6. This strongly suggests that nutrient utilization in the SAZ was dynamically coupled to dust-induced Fe fertilization across both glacial-interglacial and faster millennial timescales. In concert with ventilation changes of the deep Southern Ocean this drove ocean-atmosphere CO2 exchange and, ultimately, atmospheric pCO2 variability during the late Pleistocene.

  3. Preliminary assessment of the performance of a global coupled atmosphere-ocean model

    International Nuclear Information System (INIS)

    Cubasch, U.

    1990-01-01

    A low-resolution version of the ECMWF global atmosphere model has been coupled to a global ocean model developed at the Max Planck Institute in Hamburg. The atmosphere model is driven by the sea surface temperature and the ice thickness calculated by the ocean model, which, in return, is driven by the wind stress, the heat flux and the freshwater flux diagnosed by the atmosphere model. Even though each model reaches stationarity when integrated on its own, the coupling of both creates problems, since the fields calculated by each model are not consistent with the ones the other model has to have in order to stay stationary, because some of the fluxes are not balanced. In the coupled experiment the combined ocean-atmosphere system drifts toward a colder state. To counteract this problem, a flux correction has been applied which balances the mean biases of each model. This method almost eliminates the climate drift of the coupled model. Problems still arise over ice covered regions

  4. On the role of atmospheric forcing on upper ocean physics in the Southern Ocean and biological impacts

    Science.gov (United States)

    Carranza, Magdalena M.

    The Southern Ocean (SO) plays a key role in regulating climate by absorbing nearly half of anthropogenic carbon dioxide (CO2). Both physical and biogeochemical processes contribute to the net CO2 sink. As a result of global warming and ozone depletion, westerly winds have increased, with consequences for upper ocean physics but little is known on how primary producers are expected to respond to changes in atmospheric forcing. This thesis addresses the impact of atmospheric forcing on upper ocean dynamics and phytoplankton bloom development in the SO on synoptic storm scales, combining a broad range of observations derived from satellites, reanalysis, profiling floats and Southern elephant seals. On atmospheric synoptic timescales (2-10 days), relevant for phytoplankton growth and accumulation, wind speed has a larger impact on satellite Chl-a variability than surface heat fluxes or wind stress curl. In summer, strong winds are linked to deep mixed layers, cold sea surface temperatures and enhanced satellite chlorophyll-a (Chl-a), which suggest wind-driven entrainment plays a role in sustaining phytoplankton blooms at the surface. Subsurface bio-optical data from floats and seals reveal deep Chl-a fluorescence maxima (DFM) are ubiquitous in summer and tend to sit at the base of the mixed layer, but can occur in all seasons. The fact that wind speed and Chl-a correlations are maximal at zero lag time (from daily data) and incubation experiments indicate phytoplankton growth occurs 3-4 days after iron addition, suggests high winds in summer entrain Chl-a from a subsurface maximum. Vertical profiles also reveal Chl-a fluorescence unevenness within hydrographically defined mixed layers, suggesting the biological timescales of adaptation through the light gradient (i.e. growth and/or photoacclimation) are often faster than mixing timescales, and periods of quiescence between storms are long enough for biological gradients to form within the homogeneous layer in density

  5. International Comprehensive Ocean-Atmosphere Data Set (ICOADS) Release 3 Final, Individual Reports in the International Maritime Meteorological Archive Format version 1 (IMMA1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset, the International Comprehensive Ocean-Atmosphere Data Set (ICOADS), is the most widely-used freely available collection of surface marine observations,...

  6. Optimal Aide Security Information Search (OASIS)

    National Research Council Canada - National Science Library

    Kapadia, Chetna

    2005-01-01

    The purpose of the Optimal AIDE Security Information Search (OASIS) effort was to investigate and prototype a tool that can assist the network security analyst in collecting useful information to defend the networks they manage...

  7. Atmospheric acidification of mineral aerosols: a source of bioavailable phosphorus for the oceans

    Directory of Open Access Journals (Sweden)

    A. Nenes

    2011-07-01

    Full Text Available Primary productivity of continental and marine ecosystems is often limited or co-limited by phosphorus. Deposition of atmospheric aerosols provides the major external source of phosphorus to marine surface waters. However, only a fraction of deposited aerosol phosphorus is water soluble and available for uptake by phytoplankton. We propose that atmospheric acidification of aerosols is a prime mechanism producing soluble phosphorus from soil-derived minerals. Acid mobilization is expected to be pronounced where polluted and dust-laden air masses mix. Our hypothesis is supported by the soluble compositions and reconstructed pH values for atmospheric particulate matter samples collected over a 5-yr period at Finokalia, Crete. In addition, at least tenfold increase in soluble phosphorus was observed when Saharan soil and dust were acidified in laboratory experiments which simulate atmospheric conditions. Aerosol acidification links bioavailable phosphorus supply to anthropogenic and natural acidic gas emissions, and may be a key regulator of ocean biogeochemistry.

  8. A distributed atmosphere-sea ice-ocean observatory in the central Arctic Ocean: concept and first results

    Science.gov (United States)

    Hoppmann, Mario; Nicolaus, Marcel; Rabe, Benjamin; Wenzhöfer, Frank; Katlein, Christian; Scholz, Daniel; Valcic, Lovro

    2017-04-01

    To understand the current evolution of the Arctic Ocean towards a less extensive, thinner and younger sea ice cover is one of the biggest challenges in climate research. Especially the lack of simultaneous in-situ observations of sea ice, ocean and atmospheric properties leads to significant knowledge gaps in their complex interactions, and how the associated processes impact the polar marine ecosystem. Here we present a concept for the implementation of a long-term strategy to monitor the most essential climate- and ecosystem parameters in the central Arctic Ocean, year round and synchronously. The basis of this strategy is the development and enhancement of a number of innovative autonomous observational platforms, such as rugged weather stations, ice mass balance buoys, ice-tethered bio-optical buoys and upper ocean profilers. The deployment of those complementing platforms in a distributed network enables the simultaneous collection of physical and biogeochemical in-situ data on basin scales and year round, including the largely undersampled winter periods. A key advantage over other observatory systems is that the data is sent via satellite in near-real time, contributing to numerical weather predictions through the Global Telecommunication System (GTS) and to the International Arctic Buoy Programme (IABP). The first instruments were installed on ice floes in the Eurasian Basin in spring 2015 and 2016, yielding exceptional records of essential climate- and ecosystem-relevant parameters in one of the most inaccessible regions of this planet. Over the next 4 years, and including the observational periods of the Year of Polar Prediction (YOPP, 2017-2019) and the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC, 2020), the distributed observatory will be maintained by deployment of additional instruments in the central Arctic each year, benefitting from international logistical efforts.

  9. South African integrated carbon observation network (SA-ICON): CO2 measurements on land, atmosphere and ocean

    CSIR Research Space (South Africa)

    Feig, Gregor T

    2016-10-01

    Full Text Available It has become essential to accurately estimate the emission and uptake of atmospheric carbon dioxide (CO(sub2)) around the globe. Atmospheric CO(sub2) plays a central role in the Earth’s atmospheric, ocean and terrestrial systems and it has been...

  10. Atmospheric correction using near-infrared bands for satellite ocean color data processing in the turbid western Pacific region.

    Science.gov (United States)

    Wang, Menghua; Shi, Wei; Jiang, Lide

    2012-01-16

    A regional near-infrared (NIR) ocean normalized water-leaving radiance (nL(w)(λ)) model is proposed for atmospheric correction for ocean color data processing in the western Pacific region, including the Bohai Sea, Yellow Sea, and East China Sea. Our motivation for this work is to derive ocean color products in the highly turbid western Pacific region using the Geostationary Ocean Color Imager (GOCI) onboard South Korean Communication, Ocean, and Meteorological Satellite (COMS). GOCI has eight spectral bands from 412 to 865 nm but does not have shortwave infrared (SWIR) bands that are needed for satellite ocean color remote sensing in the turbid ocean region. Based on a regional empirical relationship between the NIR nL(w)(λ) and diffuse attenuation coefficient at 490 nm (K(d)(490)), which is derived from the long-term measurements with the Moderate-resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite, an iterative scheme with the NIR-based atmospheric correction algorithm has been developed. Results from MODIS-Aqua measurements show that ocean color products in the region derived from the new proposed NIR-corrected atmospheric correction algorithm match well with those from the SWIR atmospheric correction algorithm. Thus, the proposed new atmospheric correction method provides an alternative for ocean color data processing for GOCI (and other ocean color satellite sensors without SWIR bands) in the turbid ocean regions of the Bohai Sea, Yellow Sea, and East China Sea, although the SWIR-based atmospheric correction approach is still much preferred. The proposed atmospheric correction methodology can also be applied to other turbid coastal regions.

  11. Specificity of Atmospheric Correction of Satellite Data on Ocean Color in the Far East

    Science.gov (United States)

    Aleksanin, A. I.; Kachur, V. A.

    2017-12-01

    Calculation errors in ocean-brightness coefficients in the Far Eastern are analyzed for two atmospheric correction algorithms (NIR and MUMM). The daylight measurements in different water types show that the main error component is systematic and has a simple dependence on the magnitudes of the coefficients. The causes of the error behavior are considered. The most probable explanation for the large errors in ocean-color parameters in the Far East is a high concentration of continental aerosol absorbing light. A comparison between satellite and in situ measurements at AERONET stations in the United States and South Korea has been made. It is shown the errors in these two regions differ by up to 10 times upon close water turbidity and relatively high aerosol optical-depth computation precision in the case of using the NIR correction of the atmospheric effect.

  12. Earth orientation and its excitations by atmosphere, oceans, and geomagnetic jerks

    OpenAIRE

    Vondrák J.; Ron C.

    2015-01-01

    In addition to torques exerted by the Moon, Sun, and planets, changes of the Earth orientation parameters (EOP) are known to be caused also by excitations by the atmosphere and oceans. Recently appeared studies, hinting that geomagnetic jerks (GMJ, rapid changes of geomagnetic field) might be associated with sudden changes of phase and amplitude of EOP (Holme and de Viron 2005, 2013, Gibert and Le Mouёl 2008, Malkin 2013). We (Ron et al. 2015) used addition...

  13. A Statistical Evaluation of Atmosphere-Ocean General Circulation Models: Complexity vs. Simplicity

    OpenAIRE

    Robert K. Kaufmann; David I. Stern

    2004-01-01

    The principal tools used to model future climate change are General Circulation Models which are deterministic high resolution bottom-up models of the global atmosphere-ocean system that require large amounts of supercomputer time to generate results. But are these models a cost-effective way of predicting future climate change at the global level? In this paper we use modern econometric techniques to evaluate the statistical adequacy of three general circulation models (GCMs) by testing thre...

  14. A contribution to the study of atmospheric aerosols in urban, marine and oceanic areas

    International Nuclear Information System (INIS)

    Butor, Jean-Francois

    1980-01-01

    A study of atmospheric aerosols, especially marine aerosols, was carried out, using impactors and nuclepore filters in association with electron microscopy techniques. The performances of the experimental device were first determined carefully and a generator of monodisperse aerosols was built at the laboratory in order to measure the efficiency of the filters used. It was demonstrated that the chief atmospheric particulate constituents could be determined by electron microscopy. The particle-size distribution of oceanic aerosols was next studied on the basis of the results of three measurement campaigns carried out in the Atlantic ocean. In Brest, where urban aerosols more or less affected by the meteorological conditions can be found superimposed to marine aerosols, an assessment was made of the effects of moderate anthropogeneous pollution on marine aerosols as measured in the Atlantic ocean. Two cases of marine aerosol disturbance, the former by an accidental marine pollution, the latter linked to a natural local phenomenon are related and a model of the marine aerosol in the Northern Atlantic ocean is proposed which takes into account the mean particle size spectra, the characteristic parameters of its three-modal distribution and the qualitative analysis of particles. (author) [fr

  15. Investigation of hurricane Ivan using the coupled ocean-atmosphere-wave-sediment transport (COAWST) model

    Science.gov (United States)

    Zambon, Joseph B.; He, Ruoying; Warner, John C.

    2014-01-01

    The coupled ocean–atmosphere–wave–sediment transport (COAWST) model is used to hindcast Hurricane Ivan (2004), an extremely intense tropical cyclone (TC) translating through the Gulf of Mexico. Sensitivity experiments with increasing complexity in ocean–atmosphere–wave coupled exchange processes are performed to assess the impacts of coupling on the predictions of the atmosphere, ocean, and wave environments during the occurrence of a TC. Modest improvement in track but significant improvement in intensity are found when using the fully atmosphere–ocean-wave coupled configuration versus uncoupled (e.g., standalone atmosphere, ocean, or wave) model simulations. Surface wave fields generated in the fully coupled configuration also demonstrates good agreement with in situ buoy measurements. Coupled and uncoupled model-simulated sea surface temperature (SST) fields are compared with both in situ and remote observations. Detailed heat budget analysis reveals that the mixed layer temperature cooling in the deep ocean (on the shelf) is caused primarily by advection (equally by advection and diffusion).

  16. Combined Atmospheric and Ocean Profiling from an Airborne High Spectral Resolution Lidar

    Directory of Open Access Journals (Sweden)

    Hair Johnathan

    2016-01-01

    Full Text Available First of its kind combined atmospheric and ocean profile data were collected by the recently upgraded NASA Langley Research Center’s (LaRC High Spectral Resolution Lidar (HSRL-1 during the 17 July – 7 August 2014 Ship-Aircraft Bio-Optical Research Experiment (SABOR. This mission sampled over a region that covered the Gulf of Maine, open-ocean near Bermuda, and coastal waters from Virginia to Rhode Island. The HSRL-1 and the Research Scanning Polarimeter from NASA Goddard Institute for Space Studies collected data onboard the NASA LaRC King Air aircraft and flight operations were closely coordinated with the Research Vessel Endeavor that made in situ ocean optical measurements. The lidar measurements provided profiles of atmospheric backscatter and particulate depolarization at 532nm, 1064nm, and extinction (532nm from approximately 9km altitude. In addition, for the first time HSRL seawater backscatter, depolarization, and diffuse attenuation data at 532nm were collected and compared to both the ship measurements and the Moderate Resolution Imaging Spectrometer (NASA MODIS-Aqua satellite ocean retrievals.

  17. Autumn atmospheric response to the 2007 low Arctic sea ice extent in coupled ocean-atmosphere hindcasts

    Energy Technology Data Exchange (ETDEWEB)

    Orsolini, Yvan J. [Norwegian Institute for Air Research (NILU), PO BOX 100, Kjeller (Norway); Senan, Retish; Benestad, Rasmus E.; Melsom, Arne [Norwegian Meteorological Institute (met. no), Oslo (Norway)

    2012-06-15

    The autumn and early winter atmospheric response to the record-low Arctic sea ice extent at the end of summer 2007 is examined in ensemble hindcasts with prescribed sea ice extent, made with the European Centre for Medium-Range Weather Forecasts state-of-the-art coupled ocean-atmosphere seasonal forecast model. Robust, warm anomalies over the Pacific and Siberian sectors of the Arctic, as high as 10 C at the surface, are found in October and November. A regime change occurs by December, characterized by weaker temperatures anomalies extending through the troposphere. Geopotential anomalies extend from the surface up to the stratosphere, associated to deeper Aleutian and Icelandic Lows. While the upper-level jet is weakened and shifted southward over the continents, it is intensified over both oceanic sectors, especially over the Pacific Ocean. On the American and Eurasian continents, intensified surface Highs are associated with anomalous advection of cold (warm) polar air on their eastern (western) sides, bringing cooler temperatures along the Pacific coast of Asia and Northeastern North America. Transient eddy activity is reduced over Eurasia, intensified over the entrance and exit regions of the Pacific and Atlantic storm tracks, in broad qualitative agreement with the upper-level wind anomalies. Potential predictability calculations indicate a strong influence of sea ice upon surface temperatures over the Arctic in autumn, but also along the Pacific coast of Asia in December. When the observed sea ice extent from 2007 is prescribed throughout the autumn, a higher correlation of surface temperatures with meteorological re-analyses is found at high latitudes from October until mid-November. This further emphasises the relevance of sea ice for seasonal forecasting in the Arctic region, in the autumn. (orig.)

  18. Decadal Variations in Eastern Canada's Taiga Wood Biomass Production Forced by Ocean-Atmosphere Interactions.

    Science.gov (United States)

    Boucher, Etienne; Nicault, Antoine; Arseneault, Dominique; Bégin, Yves; Karami, Mehdi Pasha

    2017-05-26

    Across Eastern Canada (EC), taiga forests represent an important carbon reservoir, but the extent to which climate variability affects this ecosystem over decades remains uncertain. Here, we analyze an extensive network of black spruce (Picea mariana Mill.) ring width and wood density measurements and provide new evidence that wood biomass production is influenced by large-scale, internal ocean-atmosphere processes. We show that while black spruce wood biomass production is primarily governed by growing season temperatures, the Atlantic ocean conveys heat from the subtropics and influences the decadal persistence in taiga forests productivity. Indeed, we argue that 20-30 years periodicities in Sea Surface Temperatures (SSTs) as part of the the Atlantic Multi-decadal Oscillation (AMO) directly influence heat transfers to adjacent lands. Winter atmospheric conditions associated with the North Atlantic Oscillation (NAO) might also impact EC's taiga forests, albeit indirectly, through its effect on SSTs and sea ice conditions in surrounding seas. Our work emphasizes that taiga forests would benefit from the combined effects of a warmer atmosphere and stronger ocean-to-land heat transfers, whereas a weakening of these transfers could cancel out, for decades or longer, the positive effects of climate change on Eastern Canada's largest ecosystem.

  19. Role of atmosphere-ocean interactions in supermodeling the tropical Pacific climate

    Science.gov (United States)

    Shen, Mao-Lin; Keenlyside, Noel; Bhatt, Bhuwan C.; Duane, Gregory S.

    2017-12-01

    The supermodel strategy interactively combines several models to outperform the individual models comprising it. A key advantage of the approach is that nonlinear improvements can be achieved, in contrast to the linear weighted combination of individual unconnected models. This property is found in a climate supermodel constructed by coupling two versions of an atmospheric model differing only in their convection scheme to a single ocean model. The ocean model receives a weighted combination of the momentum and heat fluxes. Optimal weights can produce a supermodel with a basic state similar to observations: a single Intertropical Convergence zone (ITCZ), with a western Pacific warm pool and an equatorial cold tongue. This is in stark contrast to the erroneous double ITCZ pattern simulated by both of the two stand-alone coupled models. By varying weights, we develop a conceptual scheme to explain how combining the momentum fluxes of the two different atmospheric models affects equatorial upwelling and surface wind feedback so as to give a realistic basic state in the tropical Pacific. In particular, we propose a mechanism based on the competing influences of equatorial zonal wind and off-equatorial wind stress curl in driving equatorial upwelling in the coupled models. Our results show how nonlinear ocean-atmosphere interaction is essential in combining these two effects to build different sea surface temperature structures, some of which are realistic. They also provide some insight into observed and modelled tropical Pacific climate.

  20. Longitudinal biases in the Seychelles Dome simulated by 35 ocean-atmosphere coupled general circulation models

    Science.gov (United States)

    Nagura, Motoki; Sasaki, Wataru; Tozuka, Tomoki; Luo, Jing-Jia; Behera, Swadhin K.; Yamagata, Toshio

    2013-02-01

    Seychelles Dome refers to the shallow climatological thermocline in the southwestern Indian Ocean, where ocean wave dynamics efficiently affect sea surface temperature, allowing sea surface temperature anomalies to be predicted up to 1-2 years in advance. Accurate reproduction of the dome by ocean-atmosphere coupled general circulation models (CGCMs) is essential for successful seasonal predictions in the Indian Ocean. This study examines the Seychelles Dome as simulated by 35 CGCMs, including models used in phase five of the Coupled Model Intercomparison Project (CMIP5). Among the 35 CGCMs, 14 models erroneously produce an upwelling dome in the eastern half of the basin whereas the observed Seychelles Dome is located in the southwestern tropical Indian Ocean. The annual mean Ekman pumping velocity in these models is found to be almost zero in the southern off-equatorial region. This result is inconsistent with observations, in which Ekman upwelling acts as the main cause of the Seychelles Dome. In the models reproducing an eastward-displaced dome, easterly biases are prominent along the equator in boreal summer and fall, which result in shallow thermocline biases along the Java and Sumatra coasts via Kelvin wave dynamics and a spurious upwelling dome in the region. Compared to the CMIP3 models, the CMIP5 models are even worse in simulating the dome longitudes.

  1. The Double ITCZ Syndrome in GCMs: A Coupled Problem among Convection, Atmospheric and Ocean Circulations

    Science.gov (United States)

    Zhang, G. J.; Song, X.

    2017-12-01

    The double ITCZ bias has been a long-standing problem in coupled atmosphere-ocean models. A previous study indicates that uncertainty in the projection of global warming due to doubling of CO2 is closely related to the double ITCZ biases in global climate models. Thus, reducing the double ITCZ biases is not only important to getting the current climate features right, but also important to narrowing the uncertainty in future climate projection. In this work, we will first review the possible factors contributing to the ITCZ problem. Then, we will focus on atmospheric convection, presenting recent progress in alleviating the double ITCZ problem and its sensitivity to details of convective parameterization, including trigger conditions for convection onset, convective memory, entrainment rate, updraft model and closure in the NCAR CESM1. These changes together can result in dramatic improvements in the simulation of ITCZ. Results based on both atmospheric only and coupled simulations with incremental changes of convection scheme will be shown to demonstrate the roles of convection parameterization and coupled interaction between convection, atmospheric circulation and ocean circulation in the simulation of ITCZ.

  2. Crustal tracers in the atmosphere and ocean: Relating their concentrations, fluxes, and ages

    Science.gov (United States)

    Han, Qin

    Crustal tracers are important sources of key limiting nutrients (e.g., iron) in remote ocean regions where they have a large impact on global biogeochemical cycles. However, the atmospheric delivery of bio-available iron to oceans via mineral dust aerosol deposition is poorly constrained. This dissertation aims to improve understanding and model representation of oceanic dust deposition and to provide soluble iron flux maps by testing observations of crustal tracer concentrations and solubilities against predictions from two conceptual solubility models. First, we assemble a database of ocean surface dissolved Al and incorporate Al cycling into the global Biogeochemical Elemental Cycling (BEC) model. The observed Al concentrations show clear basin-scale differences that are useful for constraining dust deposition. The dynamic mixed layer depth and Al residence time in the BEC model significantly improve the simulated dissolved Al field. Some of the remaining model-data discrepancies appear related to the neglect of aerosol size, age, and air mass characteristics in estimating tracer solubility. Next, we develop the Mass-Age Tracking method (MAT) to efficiently and accurately estimate the mass-weighted age of tracers. We apply MAT to four sizes of desert dust aerosol and simulate, for the first time, global distributions of aerosol age in the atmosphere and at deposition. These dust size and age distributions at deposition, together with independent information on air mass acidity, allow us to test two simple yet plausible models for predicting the dissolution of mineral dust iron and aluminum during atmospheric transport. These models represent aerosol solubility as controlled (1) by a diffusive process leaching nutrients from the dust into equilibrium with the liquid water coating or (2) by a process that continually dissolves nutrients in proportion to the particle surface area. The surface-controlled model better captures the spatial pattern of observed

  3. A Concept for Differential Absorption Lidar and Radar Remote Sensing of the Earth's Atmosphere and Ocean from NRHO Orbit

    Science.gov (United States)

    Hu, Y.; Marshak, A.; Omar, A.; Lin, B.; Baize, R.

    2018-02-01

    We propose a concept that will put microwave and laser transmitters on the Deep Space Gateway platform for measurements of the Earth's atmosphere and ocean. Receivers will be placed on the ground, buoys, Argo floats, and cube satellites.

  4. First Integrals of Evolution Systems and Nonlinear Stability of Stationary Solutions for the Ideal Atmospheric, Oceanic Hydrodynamical and Plasma Models

    International Nuclear Information System (INIS)

    Gordin, V.A.

    1998-01-01

    First integral of the systems of nonlinear equations governing the behaviour of atmospheric, oceanic and MHD plasma models are determined. The Lyapunov stability conditions for the solutions under small initial disturbances are analyzed. (author)

  5. Improving estimations of greenhouse gas transfer velocities by atmosphere-ocean couplers in Earth-System and regional models

    Science.gov (United States)

    Vieira, V. M. N. C. S.; Sahlée, E.; Jurus, P.; Clementi, E.; Pettersson, H.; Mateus, M.

    2015-09-01

    Earth-System and regional models, forecasting climate change and its impacts, simulate atmosphere-ocean gas exchanges using classical yet too simple generalizations relying on wind speed as the sole mediator while neglecting factors as sea-surface agitation, atmospheric stability, current drag with the bottom, rain and surfactants. These were proved fundamental for accurate estimates, particularly in the coastal ocean, where a significant part of the atmosphere-ocean greenhouse gas exchanges occurs. We include several of these factors in a customizable algorithm proposed for the basis of novel couplers of the atmospheric and oceanographic model components. We tested performances with measured and simulated data from the European coastal ocean, having found our algorithm to forecast greenhouse gas exchanges largely different from the forecasted by the generalization currently in use. Our algorithm allows calculus vectorization and parallel processing, improving computational speed roughly 12× in a single cpu core, an essential feature for Earth-System models applications.

  6. The impact on atmospheric CO2 of iron fertilization induced changes in the ocean's biological pump

    Directory of Open Access Journals (Sweden)

    J. C. McWilliams

    2008-03-01

    Full Text Available Using numerical simulations, we quantify the impact of changes in the ocean's biological pump on the air-sea balance of CO2 by fertilizing a small surface patch in the high-nutrient, low-chlorophyll region of the eastern tropical Pacific with iron. Decade-long fertilization experiments are conducted in a basin-scale, eddy-permitting coupled physical/biogeochemical/ecological model. In contrast to previous studies, we find that most of the dissolved inorganic carbon (DIC removed from the euphotic zone by the enhanced biological export is replaced by uptake of CO2 from the atmosphere. Atmospheric uptake efficiencies, the ratio of the perturbation in air-sea CO2 flux to the perturbation in export flux across 100 m, integrated over 10 years, are 0.75 to 0.93 in our patch size-scale experiments. The atmospheric uptake efficiency is insensitive to the duration of the experiment. The primary factor controlling the atmospheric uptake efficiency is the vertical distribution of the enhanced biological production and export. Iron fertilization at the surface tends to induce production anomalies primarily near the surface, leading to high efficiencies. In contrast, mechanisms that induce deep production anomalies (e.g. altered light availability tend to have a low uptake efficiency, since most of the removed DIC is replaced by lateral and vertical transport and mixing. Despite high atmospheric uptake efficiencies, patch-scale iron fertilization of the ocean's biological pump tends to remove little CO2 from the atmosphere over the decadal timescale considered here.

  7. The impact on atmospheric CO2 of iron fertilization induced changes in the ocean's biological pump

    Science.gov (United States)

    Jin, X.; Gruber, N.; Frenzel, H.; Doney, S. C.; McWilliams, J. C.

    2008-03-01

    Using numerical simulations, we quantify the impact of changes in the ocean's biological pump on the air-sea balance of CO2 by fertilizing a small surface patch in the high-nutrient, low-chlorophyll region of the eastern tropical Pacific with iron. Decade-long fertilization experiments are conducted in a basin-scale, eddy-permitting coupled physical/biogeochemical/ecological model. In contrast to previous studies, we find that most of the dissolved inorganic carbon (DIC) removed from the euphotic zone by the enhanced biological export is replaced by uptake of CO2 from the atmosphere. Atmospheric uptake efficiencies, the ratio of the perturbation in air-sea CO2 flux to the perturbation in export flux across 100 m, integrated over 10 years, are 0.75 to 0.93 in our patch size-scale experiments. The atmospheric uptake efficiency is insensitive to the duration of the experiment. The primary factor controlling the atmospheric uptake efficiency is the vertical distribution of the enhanced biological production and export. Iron fertilization at the surface tends to induce production anomalies primarily near the surface, leading to high efficiencies. In contrast, mechanisms that induce deep production anomalies (e.g. altered light availability) tend to have a low uptake efficiency, since most of the removed DIC is replaced by lateral and vertical transport and mixing. Despite high atmospheric uptake efficiencies, patch-scale iron fertilization of the ocean's biological pump tends to remove little CO2 from the atmosphere over the decadal timescale considered here.

  8. Mechanism of climate change over South America during the LGM in coupled Ocean- Atmosphere model simulations

    Science.gov (United States)

    Khodri, M.

    2006-12-01

    On a regional perspective the database of proxy information for South America during the Last Glacial Maximum (LGM) shows large and regionally extensive changes of the mean climate and vegetation types over the Amazon basin. In some instances these changes were associated with decrease in the mean precipitation amount (and most probably in moist deep convection) over the Amazonian and South East Brazil monsoon regions and wetter mean conditions in present day drought-prone regions such as Northeast of Brazil (Nordeste). These changes have been interpreted as local responses to shift in the mean position and intensity of the Atlantic ITCZ due to glacial extratropical forcings or to changes in the South American Monsoons. However there are still two issues is the path to further understand the mechanism of climate change over South America during the LGM. The first is incomplete knowledge in both the modeling and observational communities of how the moist deep convection over the Amazonian region respond to glacial boundary condition and how this changes might interact with the meridional shift of rainfall over Nordeste and Atlantic Ocean. The second is our understanding of how ocean-atmosphere changes that do occur in the tropical Pacific region influence the climate of the remainder of the planet and on a regional way over South America. Using PMIP-2 coupled Ocean-Atmosphere simulations for LGM and comparison to paleodata we show that hydrological cycle changes over the Amazon basin might be independent of their Atlantic Ocean counterpart, while teleconnections with Pacific Ocean might have played a significant role in the observed changes over tropical South America.

  9. Bioavailable atmospheric phosphorous supply to the global ocean: a 3-D global modeling study

    Science.gov (United States)

    Myriokefalitakis, Stelios; Nenes, Athanasios; Baker, Alex R.; Mihalopoulos, Nikolaos; Kanakidou, Maria

    2016-12-01

    The atmospheric cycle of phosphorus (P) is parameterized here in a state-of-the-art global 3-D chemistry transport model, taking into account primary emissions of total P (TP) and soluble P (DP) associated with mineral dust, combustion particles from natural and anthropogenic sources, bioaerosols, sea spray and volcanic aerosols. For the present day, global TP emissions are calculated to be roughly 1.33 Tg-P yr-1, with the mineral sources contributing more than 80 % to these emissions. The P solubilization from mineral dust under acidic atmospheric conditions is also parameterized in the model and is calculated to contribute about one-third (0.14 Tg-P yr-1) of the global DP atmospheric source. To our knowledge, a unique aspect of our global study is the explicit modeling of the evolution of phosphorus speciation in the atmosphere. The simulated present-day global annual DP deposition flux is 0.45 Tg-P yr-1 (about 40 % over oceans), showing a strong spatial and temporal variability. Present-day simulations of atmospheric P aerosol concentrations and deposition fluxes are satisfactory compared with available observations, indicating however an underestimate of about 70 % on current knowledge of the sources that drive the P atmospheric cycle. Sensitivity simulations using preindustrial (year 1850) anthropogenic and biomass burning emission scenarios showed a present-day increase of 75 % in the P solubilization flux from mineral dust, i.e., the rate at which P is converted into soluble forms, compared to preindustrial times, due to increasing atmospheric acidity over the last 150 years. Future reductions in air pollutants due to the implementation of air-quality regulations are expected to decrease the P solubilization flux from mineral dust by about 30 % in the year 2100 compared to the present day. Considering, however, that all the P contained in bioaerosols is readily available for uptake by marine organisms, and also accounting for all other DP sources, a total

  10. Orographic effects on tropical climate in a coupled ocean-atmosphere general circulation model

    Science.gov (United States)

    Okajima, Hideki

    Large-scale mountain modifies the atmospheric circulation directly through dynamic and thermodynamic process, and also indirectly through the interaction with the ocean. To investigate orographic impacts on tropical climate, a fully coupled general circulation model (CGCM) is developed by coupling a state-of-the-art atmospheric general circulation model and an ocean general circulation model. With realistic boundary conditions, the CGCM produces a reasonable climatology of sea surface temperature (SST), surface winds, and precipitation. When global mountains are removed, the model climatology displays substantial changes in both the mean-state and the seasonal cycle. The equatorial eastern Pacific SST acquires a semi-annual component as inter-tropical convergence zone (ITCZ) flips and flops across the equator following the seasonal migration of the sun. Without the Andes, wet air flows into the southeastern tropical Pacific from the humid Amazon, which weakens the meridional asymmetry during the Peruvian warm season (February-April). In addition, the northeasterly trade winds are enhanced north of the equator without the orographic blocking of Central American mountains and cools SST. Triggered by the SST cooling north and moistening south of the equator, the wind-evaporation-SST (WES) feedback further weakens the meridional asymmetry and prolongs the southern ITCZ. In the Atlantic Ocean, the equatorial cold tongue is substantially strengthened and develops a pronounced annual cycle in the absence of mountains. The easterly winds are overall enhanced over the equatorial Atlantic without orographic heating over the African highlands, developing a zonal asymmetry strengthened by the Bjerknes feedback. In the Indian Ocean, the thermocline shoals eastward and an equatorial cold tongue appears twice a year. During boreal summer, the Findlater jet is greatly weakened off Somalia and SST warms in the western Indian Ocean, forcing the equatorial easterly winds amplified

  11. AMS Observations over Coastal California from the Biological and Oceanic Atmospheric Study (BOAS)

    Science.gov (United States)

    Bates, K. H.; Coggon, M. M.; Hodas, N.; Negron, A.; Ortega, A. M.; Crosbie, E.; Sorooshian, A.; Nenes, A.; Flagan, R. C.; Seinfeld, J.

    2015-12-01

    In July 2015, fifteen research flights were conducted on a US Navy Twin Otter aircraft as part of the Biological and Oceanic Atmospheric Study (BOAS) campaign. The flights took place near the California coast at Monterey, to investigate the effects of sea surface temperature and algal blooms on oceanic particulate emissions, the diurnal mixing of urban pollution with other airmasses, and the impacts of biological aerosols on the California atmosphere. The aircraft's payload included an aerosol mass spectrometer (AMS), a differential mobility analyzer, a cloud condensation nuclei counter, a counterflow virtual impactor, a cloudwater collector, and two instruments designed to detect biological aerosols - a wideband integrated biological spectrometer and a SpinCon II - as well as a number of meteorology and aerosol probes, two condensation particle counters, and instruments to measure gas-phase CO, CO2, O3, and NOx. Here, we describe in depth the objectives and outcomes of BOAS and report preliminary results, primarily from the AMS. We detail the spatial characteristics and meteorological variability of speciated aerosol components over a strong and persistent bloom of Pseudo-Nitzschia, the harmful algae that cause 'red tide', and report newly identified AMS markers for biological particles. Finally, we compare these results with data collected during BOAS over urban, forested, and agricultural environments, and describe the mixing observed between oceanic and terrestrial airmasses.

  12. Numerical simulation of small-scale mixing processes in the upper ocean and atmospheric boundary layer

    International Nuclear Information System (INIS)

    Druzhinin, O; Troitskaya, Yu; Zilitinkevich, S

    2016-01-01

    The processes of turbulent mixing and momentum and heat exchange occur in the upper ocean at depths up to several dozens of meters and in the atmospheric boundary layer within interval of millimeters to dozens of meters and can not be resolved by known large- scale climate models. Thus small-scale processes need to be parameterized with respect to large scale fields. This parameterization involves the so-called bulk coefficients which relate turbulent fluxes with large-scale fields gradients. The bulk coefficients are dependent on the properties of the small-scale mixing processes which are affected by the upper-ocean stratification and characteristics of surface and internal waves. These dependencies are not well understood at present and need to be clarified. We employ Direct Numerical Simulation (DNS) as a research tool which resolves all relevant flow scales and does not require closure assumptions typical of Large-Eddy and Reynolds Averaged Navier-Stokes simulations (LES and RANS). Thus DNS provides a solid ground for correct parameterization of small-scale mixing processes and also can be used for improving LES and RANS closure models. In particular, we discuss the problems of the interaction between small-scale turbulence and internal gravity waves propagating in the pycnocline in the upper ocean as well as the impact of surface waves on the properties of atmospheric boundary layer over wavy water surface. (paper)

  13. The Abundance of Atmospheric CO{sub 2} in Ocean Exoplanets: a Novel CO{sub 2} Deposition Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Levi, A.; Sasselov, D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Podolak, M., E-mail: amitlevi.planetphys@gmail.com [Dept. of Geosciences, Tel Aviv University, Tel Aviv, 69978 (Israel)

    2017-03-20

    We consider super-Earth sized planets which have a water mass fraction large enough to form an external mantle composed of high-pressure water-ice polymorphs and also lack a substantial H/He atmosphere. We consider such planets in their habitable zone, so that their outermost condensed mantle is a global, deep, liquid ocean. For these ocean planets, we investigate potential internal reservoirs of CO{sub 2}, the amount of CO{sub 2} dissolved in the ocean for the various saturation conditions encountered, and the ocean-atmosphere exchange flux of CO{sub 2}. We find that, in a steady state, the abundance of CO{sub 2} in the atmosphere has two possible states. When wind-driven circulation is the dominant CO{sub 2} exchange mechanism, an atmosphere of tens of bars of CO{sub 2} results, where the exact value depends on the subtropical ocean surface temperature and the deep ocean temperature. When sea-ice formation, acting on these planets as a CO{sub 2} deposition mechanism, is the dominant exchange mechanism, an atmosphere of a few bars of CO{sub 2} is established. The exact value depends on the subpolar surface temperature. Our results suggest the possibility of a negative feedback mechanism, unique to water planets, where a reduction in the subpolar temperature drives more CO{sub 2} into the atmosphere to increase the greenhouse effect.

  14. Interhemispheric gradient of atmospheric radiocarbon reveals natural variability of Southern Ocean winds

    Science.gov (United States)

    Rodgers, K. B.; Mikaloff-Fletcher, S. E.; Bianchi, D.; Beaulieu, C.; Galbraith, E. D.; Gnanadesikan, A.; Hogg, A. G.; Iudicone, D.; Lintner, B. R.; Naegler, T.; Reimer, P. J.; Sarmiento, J. L.; Slater, R. D.

    2011-10-01

    Tree ring Δ14C data (Reimer et al., 2004; McCormac et al., 2004) indicate that atmospheric Δ14C varied on multi-decadal to centennial timescales, in both hemispheres, over the period between AD 950 and 1830. The Northern and Southern Hemispheric Δ14C records display similar variability, but from the data alone is it not clear whether these variations are driven by the production of 14C in the stratosphere (Stuiver and Quay, 1980) or by perturbations to exchanges between carbon reservoirs (Siegenthaler et al., 1980). As the sea-air flux of 14CO2 has a clear maximum in the open ocean regions of the Southern Ocean, relatively modest perturbations to the winds over this region drive significant perturbations to the interhemispheric gradient. In this study, model simulations are used to show that Southern Ocean winds are likely a main driver of the observed variability in the interhemispheric gradient over AD 950-1830, and further, that this variability may be larger than the Southern Ocean wind trends that have been reported for recent decades (notably 1980-2004). This interpretation also implies that there may have been a significant weakening of the winds over the Southern Ocean within a few decades of AD 1375, associated with the transition between the Medieval Climate Anomaly and the Little Ice Age. The driving forces that could have produced such a shift in the winds at the Medieval Climate Anomaly to Little Ice Age transition remain unknown. Our process-focused suite of perturbation experiments with models raises the possibility that the current generation of coupled climate and earth system models may underestimate the natural background multi-decadal- to centennial-timescale variations in the winds over the Southern Ocean.

  15. Interhemispheric gradient of atmospheric radiocarbon reveals natural variability of Southern Ocean winds

    Directory of Open Access Journals (Sweden)

    K. B. Rodgers

    2011-10-01

    Full Text Available Tree ring Δ14C data (Reimer et al., 2004; McCormac et al., 2004 indicate that atmospheric Δ14C varied on multi-decadal to centennial timescales, in both hemispheres, over the period between AD 950 and 1830. The Northern and Southern Hemispheric Δ14C records display similar variability, but from the data alone is it not clear whether these variations are driven by the production of 14C in the stratosphere (Stuiver and Quay, 1980 or by perturbations to exchanges between carbon reservoirs (Siegenthaler et al., 1980. As the sea-air flux of 14CO2 has a clear maximum in the open ocean regions of the Southern Ocean, relatively modest perturbations to the winds over this region drive significant perturbations to the interhemispheric gradient. In this study, model simulations are used to show that Southern Ocean winds are likely a main driver of the observed variability in the interhemispheric gradient over AD 950–1830, and further, that this variability may be larger than the Southern Ocean wind trends that have been reported for recent decades (notably 1980–2004. This interpretation also implies that there may have been a significant weakening of the winds over the Southern Ocean within a few decades of AD 1375, associated with the transition between the Medieval Climate Anomaly and the Little Ice Age. The driving forces that could have produced such a shift in the winds at the Medieval Climate Anomaly to Little Ice Age transition remain unknown. Our process-focused suite of perturbation experiments with models raises the possibility that the current generation of coupled climate and earth system models may underestimate the natural background multi-decadal- to centennial-timescale variations in the winds over the Southern Ocean.

  16. Radiative transfer modeling through terrestrial atmosphere and ocean accounting for inelastic processes: Software package SCIATRAN

    International Nuclear Information System (INIS)

    Rozanov, V.V.; Dinter, T.; Rozanov, A.V.; Wolanin, A.; Bracher, A.; Burrows, J.P.

    2017-01-01

    SCIATRAN is a comprehensive software package which is designed to model radiative transfer processes in the terrestrial atmosphere and ocean in the spectral range from the ultraviolet to the thermal infrared (0.18–40 μm). It accounts for multiple scattering processes, polarization, thermal emission and ocean–atmosphere coupling. The main goal of this paper is to present a recently developed version of SCIATRAN which takes into account accurately inelastic radiative processes in both the atmosphere and the ocean. In the scalar version of the coupled ocean–atmosphere radiative transfer solver presented by Rozanov et al. we have implemented the simulation of the rotational Raman scattering, vibrational Raman scattering, chlorophyll and colored dissolved organic matter fluorescence. In this paper we discuss and explain the numerical methods used in SCIATRAN to solve the scalar radiative transfer equation including trans-spectral processes, and demonstrate how some selected radiative transfer problems are solved using the SCIATRAN package. In addition we present selected comparisons of SCIATRAN simulations with those published benchmark results, independent radiative transfer models, and various measurements from satellite, ground-based, and ship-borne instruments. The extended SCIATRAN software package along with a detailed User's Guide is made available for scientists and students, who are undertaking their own research typically at universities, via the web page of the Institute of Environmental Physics (IUP), University of Bremen: (http://www.iup.physik.uni-bremen.de). - Highlights: • A new version of the software package SCIATRAN is presented. • Inelastic scattering in water and atmosphere is implemented in SCIATRAN. • Raman scattering and fluorescence can be included in radiative transfer calculations. • Comparisons to other radiative transfer models show excellent agreement. • Comparisons to observations show consistent results.

  17. Thermodynamic ocean-atmosphere Coupling and the Predictability of Nordeste rainfall

    Science.gov (United States)

    Chang, P.; Saravanan, R.; Giannini, A.

    2003-04-01

    The interannual variability of rainfall in the northeastern region of Brazil, or Nordeste, is known to be very strongly correlated with sea surface temperature (SST) variability, of Atlantic and Pacific origin. For this reason the potential predictability of Nordeste rainfall is high. The current generation of state-of-the-art atmospheric models can replicate the observed rainfall variability with high skill when forced with the observed record of SST variability. The correlation between observed and modeled indices of Nordeste rainfall, in the AMIP-style integrations with two such models (NSIPP and CCM3) analyzed here, is of the order of 0.8, i.e. the models explain about 2/3 of the observed variability. Assuming that thermodynamic, ocean-atmosphere heat exchange plays the dominant role in tropical Atlantic SST variability on the seasonal to interannual time scale, we analyze its role in Nordeste rainfall predictability using an atmospheric general circulation model coupled to a slab ocean model. Predictability experiments initialized with observed December SST show that thermodynamic coupling plays a significant role in enhancing the persistence of SST anomalies, both in the tropical Pacific and in the tropical Atlantic. We show that thermodynamic coupling is sufficient to provide fairly accurate forecasts of tropical Atlantic SST in the boreal spring that are significantly better than the persistence forecasts. The consequences for the prediction of Nordeste rainfall are analyzed.

  18. (Semi)volatile organic compounds and microbiological entities in snow during OASIS Barrow 2009

    Science.gov (United States)

    Ariya, P.; Kos, G.

    2009-12-01

    Gregor Kos (1), Nafissa Adechina (2), Dwayne Lutchmann (2) , Roya Mortazavi, and Parisa Ariya* (1), (2) (1) McGill University, Department of Atmospheric and Oceanic Sciences, 805 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada (2) McGill University, Department of Chemistry, 801 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada an active medium for the deposition of (semi-)volatile (bio)organic compounds. We collected surface snow samples during the OASIS Barrow campaign in March 2009 for analysis of semi-volatile organic compounds using solid phase microextraction and gas chromatography with mass spectrometric detection (SPME-GC/MS). Additioal gab samples were taken for analysis of non-methane hydrocarbons in air. More over, we analyzed for microbial species in air and snow. Identifed organic compounds covered a wide range of functionalities andmolecular weigts, including oxygenated reactive speces such as aldehydes (e.g., hexanal to decanal), alcohols (e.g., hexanol, octanol) and aromatic species (e.g., methyl- and ethylbenzenes). Quantification data for selected aromatic species are presented with concentrations in the upper ng/L range. We will present our preliminary data on microbiological species, and will discuss the potential mplications of the results for organic snow chemistry.

  19. Dust storms and their impact on ocean and human health: dust in Earth's atmosphere

    Science.gov (United States)

    Griffin, Dale W.; Kellog, Christina A.

    2004-01-01

    Satellite imagery has greatly influenced our understanding of dust activity on a global scale. A number of different satellites such as NASA's Earth-Probe Total Ozone Mapping Spectrometer (TOMS) and Se-viewing Field-of-view Sensor (SeaWiFS) acquire daily global-scale data used to produce imagery for monitoring dust storm formation and movement. This global-scale imagery has documented the frequent transmission of dust storm-derived soils through Earth's atmosphere and the magnitude of many of these events. While various research projects have been undertaken to understand this normal planetary process, little has been done to address its impact on ocean and human health. This review will address the ability of dust storms to influence marine microbial population densities and transport of soil-associated toxins and pathogenic microorganisms to marine environments. The implications of dust on ocean and human health in this emerging scientific field will be discussed.

  20. Statistical and dynamical assessment of land-ocean-atmosphere interactions across North Africa

    Science.gov (United States)

    Yu, Yan

    North Africa is highly vulnerable to hydrologic variability and extremes, including impacts of climate change. The current understanding of oceanic versus terrestrial drivers of North African droughts and pluvials is largely model-based, with vast disagreement among models in terms of the simulated oceanic impacts and vegetation feedbacks. Regarding oceanic impacts, the relative importance of the tropical Pacific, tropical Indian, and tropical Atlantic Oceans in regulating the North African rainfall variability, as well as the underlying mechanism, remains debated among different modeling studies. Classic theory of land-atmosphere interactions across the Sahel ecotone, largely based on climate modeling experiments, has promoted positive vegetation-rainfall feedbacks associated with a dominant surface albedo mechanism. However, neither the proposed positive vegetation-rainfall feedback with its underlying albedo mechanism, nor its relative importance compared with oceanic drivers, has been convincingly demonstrated up to now using observational data. Here, the multivariate Generalized Equilibrium Feedback Assessment (GEFA) is applied in order to identify the observed oceanic and terrestrial drivers of North African climate and quantify their impacts. The reliability of the statistical GEFA method is first evaluated against dynamical experiments within the Community Earth System Model (CESM). In order to reduce the sampling error caused by short data records, the traditional GEFA approach is refined through stepwise GEFA, in which unimportant forcings are dropped through stepwise selection. In order to evaluate GEFA's reliability in capturing oceanic impacts, the atmospheric response to a sea-surface temperature (SST) forcing across the tropical Pacific, tropical Indian, and tropical Atlantic Ocean is estimated independently through ensembles of dynamical experiments and compared with GEFA-based assessments. Furthermore, GEFA's performance in capturing terrestrial

  1. A physiological approach to oceanic processes and glacial-interglacial changes in atmospheric CO2

    Directory of Open Access Journals (Sweden)

    Josep L. Pelegrí

    2008-03-01

    Full Text Available One possible path for exploring the Earth’s far-from-equilibrium homeostasis is to assume that it results from the organisation of optimal pulsating systems, analogous to that in complex living beings. Under this premise it becomes natural to examine the Earth’s organisation using physiological-like variables. Here we identify some of these main variables for the ocean’s circulatory system: pump rate, stroke volume, carbon and nutrient arterial-venous differences, inorganic nutrients and carbon supply, and metabolic rate. The stroke volume is proportional to the water transported into the thermocline and deep oceans, and the arterial-venous differences occur between recently-upwelled deep waters and very productive high-latitudes waters, with atmospheric CO2 being an indicator of the arterial-venous inorganic carbon difference. The metabolic rate is the internal-energy flux (here expressed as flux of inorganic carbon in the upper ocean required by the system’s machinery, i.e. community respiration. We propose that the pump rate is set externally by the annual cycle, at one beat per year per hemisphere, and that the autotrophic ocean adjusts its stroke volume and arterial-venous differences to modify the internal-energy demand, triggered by long-period astronomical insolation cycles (external-energy supply. With this perspective we may conceive that the Earth’s interglacial-glacial cycle responds to an internal organisation analogous to that occurring in living beings during an exercise-recovery cycle. We use an idealised double-state metabolic model of the upper ocean (with the inorganic carbon/nutrients supply specified through the overturning rate and the steady-state inorganic carbon/nutrients concentrations to obtain the temporal evolution of its inorganic carbon concentration, which mimics the glacial-interglacial atmospheric CO2 pattern.

  2. Atmospheric and oceanic impacts of Antarctic glaciation across the Eocene-Oligocene transition.

    Science.gov (United States)

    Kennedy, A T; Farnsworth, A; Lunt, D J; Lear, C H; Markwick, P J

    2015-11-13

    The glaciation of Antarctica at the Eocene-Oligocene transition (approx. 34 million years ago) was a major shift in the Earth's climate system, but the mechanisms that caused the glaciation, and its effects, remain highly debated. A number of recent studies have used coupled atmosphere-ocean climate models to assess the climatic effects of Antarctic glacial inception, with often contrasting results. Here, using the HadCM3L model, we show that the global atmosphere and ocean response to growth of the Antarctic ice sheet is sensitive to subtle variations in palaeogeography, using two reconstructions representing Eocene and Oligocene geological stages. The earlier stage (Eocene; Priabonian), which has a relatively constricted Tasman Seaway, shows a major increase in sea surface temperature over the Pacific sector of the Southern Ocean in response to the ice sheet. This response does not occur for the later stage (Oligocene; Rupelian), which has a more open Tasman Seaway. This difference in temperature response is attributed to reorganization of ocean currents between the stages. Following ice sheet expansion in the earlier stage, the large Ross Sea gyre circulation decreases in size. Stronger zonal flow through the Tasman Seaway allows salinities to increase in the Ross Sea, deep-water formation initiates and multiple feedbacks then occur amplifying the temperature response. This is potentially a model-dependent result, but it highlights the sensitive nature of model simulations to subtle variations in palaeogeography, and highlights the need for coupled ice sheet-climate simulations to properly represent and investigate feedback processes acting on these time scales. © 2015 The Author(s).

  3. The declining uptake rate of atmospheric CO2 by land and ocean sinks

    Directory of Open Access Journals (Sweden)

    M. R. Raupach

    2014-07-01

    Full Text Available Through 1959–2012, an airborne fraction (AF of 0.44 of total anthropogenic CO2 emissions remained in the atmosphere, with the rest being taken up by land and ocean CO2 sinks. Understanding of this uptake is critical because it greatly alleviates the emissions reductions required for climate mitigation, and also reduces the risks and damages that adaptation has to embrace. An observable quantity that reflects sink properties more directly than the AF is the CO2 sink rate (kS, the combined land–ocean CO2 sink flux per unit excess atmospheric CO2 above preindustrial levels. Here we show from observations that kS declined over 1959–2012 by a factor of about 1 / 3, implying that CO2 sinks increased more slowly than excess CO2. Using a carbon–climate model, we attribute the decline in kS to four mechanisms: slower-than-exponential CO2 emissions growth (~ 35% of the trend, volcanic eruptions (~ 25%, sink responses to climate change (~ 20%, and nonlinear responses to increasing CO2, mainly oceanic (~ 20%. The first of these mechanisms is associated purely with the trajectory of extrinsic forcing, and the last two with intrinsic, feedback responses of sink processes to changes in climate and atmospheric CO2. Our results suggest that the effects of these intrinsic, nonlinear responses are already detectable in the global carbon cycle. Although continuing future decreases in kS will occur under all plausible CO2 emission scenarios, the rate of decline varies between scenarios in non-intuitive ways because extrinsic and intrinsic mechanisms respond in opposite ways to changes in emissions: extrinsic mechanisms cause kS to decline more strongly with increasing mitigation, while intrinsic mechanisms cause kS to decline more strongly under high-emission, low-mitigation scenarios as the carbon–climate system is perturbed further from a near-linear regime.

  4. The declining uptake rate of atmospheric CO2 by land and ocean sinks

    International Nuclear Information System (INIS)

    Raupach, M.R.; Gloor, M.; Sarmiento, J.L.; Gasser, T.

    2014-01-01

    Through 1959-2012, an airborne fraction (AF) of 0.44 of total anthropogenic CO 2 emissions remained in the atmosphere, with the rest being taken up by land and ocean CO 2 sinks. Understanding of this uptake is critical because it greatly alleviates the emissions reductions required for climate mitigation, and also reduces the risks and damages that adaptation has to embrace. An observable quantity that reflects sink properties more directly than the AF is the CO 2 sink rate (k S ), the combined land-ocean CO 2 sink flux per unit excess atmospheric CO 2 above pre industrial levels. Here we show from observations that k S declined over 1959-2012 by a factor of about 1/3, implying that CO 2 sinks increased more slowly than excess CO 2 . Using a carbon-climate model, we attribute the decline in k S to four mechanisms: slower-than-exponential CO 2 emissions growth (35% of the trend), volcanic eruptions (25 %), sink responses to climate change (20 %), and nonlinear responses to increasing CO 2 , mainly oceanic (20 %). The first of these mechanisms is associated purely with the trajectory of extrinsic forcing, and the last two with intrinsic, feedback responses of sink processes to changes in climate and atmospheric CO 2 . Our results suggest that the effects of these intrinsic, nonlinear responses are already detectable in the global carbon cycle. Although continuing future decreases in k S will occur under all plausible CO 2 emission scenarios, the rate of decline varies between scenarios in non intuitive ways because extrinsic and intrinsic mechanisms respond in opposite ways to changes in emissions: extrinsic mechanisms cause k S to decline more strongly with increasing mitigation, while intrinsic mechanisms cause k S to decline more strongly under high-emission, low-mitigation scenarios as the carbon-climate system is perturbed further from a near-linear regime. (authors)

  5. The atmospheric boundary layer response to the dynamic new Arctic Ocean

    Science.gov (United States)

    Wu, D. L.; Ganeshan, M.

    2016-12-01

    The increasing ice-free area in the Arctic Ocean has transformed its climate system to one with more dynamic boundary layer clouds and seasonal sea ice. During the fall freeze season, the surface sensible heat flux (SSHF) is a crucial mechanism for the loss of excessive ocean heat to the atmosphere, and it has been speculated to play an important role in the recent cloud cover increase and boundary layer (BL) instability observed in the Beaufort and Chukchi seas. Based on multi-year Japanese cruise ship observations from the ice-strengthened R/V Mirai, we are able to characterize the late summer and early fall ocean-BL interactions in this region. Although the BL is found to be well-mixed more than 90% of the time, the SSHF can explain only 10% of the mixed layer height variability. It is the cloud-generated convective turbulence that apparently dominates BL mixing in this ice-free region, which is similar to previous in-situ observations (SHEBA, ASCOS) over sea ice. The SSHF, however, may contribute to BL instability during conditions of uplift (low-pressure), and the presence of the highly stable stratus cloud regime. The efficiency of sensible heat exchange is low during cold air advection (associated with the stratocumulus cloud regime) despite an enhanced ocean-atmosphere temperature difference (ΔT). In general, surface-generated mixing is favored during episodes of high surface wind speeds as opposed to pronounced ΔT. Our analysis suggests a weak local response of the boundary layer stability to the loss of sea ice cover during late summer, which is masked by the strong influence of the large-scale circulation (and clouds). Apart from the fall season, we also studied the Arctic Ocean BL properties during the cold months (Nov-Apr) using multi-year satellite measurements (COSMIC RO). As the boundary layer is typically stable at this time, one might expect major differences in the nature of surface-atmosphere coupling compared to that observed during late

  6. Simulating the Holocene climate evolution at northern high latitudes using a coupled atmosphere-sea ice-ocean-vegetation model

    NARCIS (Netherlands)

    Renssen, H.; Goosse, H.; Fichefet, T.; Brovkin, V.; Driesschaert, E.; Wolk, F.

    2005-01-01

    The response of the climate at high northern latitudes to slowly changing external forcings was studied in a 9,000-year long simulation with the coupled atmosphere-sea ice-ocean-vegetation model ECBilt-CLIO-VECODE. Only long-term changes in insolation and atmospheric CO

  7. The Role of Ocean and Atmospheric Heat Transport in the Arctic Amplification

    Science.gov (United States)

    Vargas Martes, R. M.; Kwon, Y. O.; Furey, H. H.

    2017-12-01

    Observational data and climate model projections have suggested that the Arctic region is warming around twice faster than the rest of the globe, which has been referred as the Arctic Amplification (AA). While the local feedbacks, e.g. sea ice-albedo feedback, are often suggested as the primary driver of AA by previous studies, the role of meridional heat transport by ocean and atmosphere is less clear. This study uses the Community Earth System Model version 1 Large Ensemble simulation (CESM1-LE) to seek deeper understanding of the role meridional oceanic and atmospheric heat transports play in AA. The simulation consists of 40 ensemble members with the same physics and external forcing using a single fully coupled climate model. Each ensemble member spans two time periods; the historical period from 1920 to 2005 using the Coupled Model Intercomparison Project Phase 5 (CMIP5) historical forcing and the future period from 2006 to 2100 using the CMIP5 Representative Concentration Pathways 8.5 (RCP8.5) scenario. Each of the ensemble members are initialized with slightly different air temperatures. As the CESM1-LE uses a single model unlike the CMIP5 multi-model ensemble, the internal variability and the externally forced components can be separated more clearly. The projections are calculated by comparing the period 2081-2100 relative to the time period 2001-2020. The CESM1-LE projects an AA of 2.5-2.8 times faster than the global average, which is within the range of those from the CMIP5 multi-model ensemble. However, the spread of AA from the CESM1-LE, which is attributed to the internal variability, is 2-3 times smaller than that of the CMIP5 ensemble, which may also include the inter-model differences. CESM1LE projects a decrease in the atmospheric heat transport into the Arctic and an increase in the oceanic heat transport. The atmospheric heat transport is further decomposed into moisture transport and dry static energy transport. Also, the oceanic heat

  8. Uptake by the Atlantic Ocean of excess atmospheric carbon dioxide and radiocarbon

    International Nuclear Information System (INIS)

    Bolin, B.; Bjorkstrom, A.

    1989-01-01

    Inverse methods have been used to deduce water circulation, spatial patterns of turbulent exchange and biological activity in the Atlantic Ocean, by using a set of stationary tracers and a condition of quasi-geostrophic flow. The solution yields a direct meridional circulation cell with descending motion in the northern Atlantic with an intensity of 20-25 Sverdrup, a reasonable distribution of vertical turbulent transfer in the uppermost ocean layers and comparatively large rates of detritus formation, about 4.5 Pg C yr -1 . The solution is used to compute the invasion of tritium 1955-1983, and the uptake of excess radiocarbon and carbon dioxide during the period 1760-1983. A fair agreement between computed and observed changes of tritium and 14 C is obtained, but the period of observations is too short to serve as a conclusive test model. The uptake of carbon dioxide during the 220 years period into the Atlantic Ocean is 33 ± 5 Pg and it is further found that significant variations of the uptake fraction of the CO 2 emissions may have occurred due to varying rates of emissions in gorce of time. The conclusion is drawn that the ocean and its carbonate system may not have been the only sink for anthropogenic emissions of carbon dioxide into the atmosphere. Means for how to further improve the model and its capability to reproduce the ocean behaviour are discussed. Burning of fossil fuels, deforestation and changing land use have changed the global carbon cycle very significant during the last two centuries

  9. Modes of North Atlantic Decadal Variability in the ECHAM1/LSG Coupled Ocean-Atmosphere General Circulation Model.

    Science.gov (United States)

    Zorita, Eduardo; Frankignoul, Claude

    1997-02-01

    The climate variability in the North Atlantic sector is investigated in a 325-yr integration of the ECHAM1/ LSG coupled ocean-atmosphere general circulation model. At the interannual timescale, the coupled model behaves realistically and sea surface temperature (SST) anomalies arise as a response of the oceanic surface layer to the stochastic forcing by the atmosphere, with the heat exchanges both generating and damping the SST anomalies. In the ocean interior, the temperature spectra are red up to a period of about 20 years, and substantial decadal fluctuations are found in the upper kilometer or so of the water column. Using extended empirical orthogonal function analysis, two distinct quasi-oscillatory modes of ocean-atmosphere variability are identified, with dominant periods of about 20 and 10 years, respectively. The oceanic changes in both modes reflect the direct forcing by the atmosphere through anomalous air-sea fluxes and Ekman pumping, which after some delay affects the intensity of the subtropical and subpolar gyres. The SST is also strongly modulated by the gyre currents. In the thermocline, the temperature and salinity fluctuations are in phase, as if caused by thermocline displacements, and they have no apparent connection with the thermohaline circulation. The 20-yr mode is the most energetic one; it is easily seen in the thermocline and can be found in SST data, but it is not detected in the atmosphere alone. As there is no evidence of positive ocean-atmosphere feedback, the 20-yr mode primarily reflects the passive response of the ocean to atmospheric fluctuations, which may be in part associated with climate anomalies appearing a few years earlier in the North Pacific. The 10-yr mode is more surface trapped in the ocean. Although the mode is most easily seen in the temperature variations of the upper few hundred meters of the ocean, it is also detected in the atmosphere alone and thus appears to be a coupled ocean-atmosphere mode. In both modes

  10. Spatio-temporal variability of aerosols in the tropics relationship with atmospheric and oceanic environments

    Science.gov (United States)

    Zuluaga-Arias, Manuel D.

    2011-12-01

    Earth's radiation budget is directly influenced by aerosols through the absorption of solar radiation and subsequent heating of the atmosphere. Aerosols modulate the hydrological cycle indirectly by modifying cloud properties, precipitation and ocean heat storage. In addition, polluting aerosols impose health risks in local, regional and global scales. In spite of recent advances in the study of aerosols variability, uncertainty in their spatio-temporal distributions still presents a challenge in the understanding of climate variability. For example, aerosol loading varies not only from year to year but also on higher frequency intraseasonal time scales producing strong variability on local and regional scales. An assessment of the impact of aerosol variability requires long period measurements of aerosols at both regional and global scales. The present dissertation compiles a large database of remotely sensed aerosol loading in order to analyze its spatio-temporal variability, and how this load interacts with different variables that characterize the dynamic and thermodynamic states of the environment. Aerosol Index (AI) and Aerosol Optical Depth (AOD) were used as measures of the atmospheric aerosol load. In addition, atmospheric and oceanic satellite observations, and reanalysis datasets is used in the analysis to investigate aerosol-environment interactions. A diagnostic study is conducted to produce global and regional aerosol satellite climatologies, and to analyze and compare the validity of aerosol retrievals. We find similarities and differences between the aerosol distributions over various regions of the globe when comparing the different satellite retrievals. A nonparametric approach is also used to examine the spatial distribution of the recent trends in aerosol concentration. A significant positive trend was found over the Middle East, Arabian Sea and South Asian regions strongly influenced by increases in dust events. Spectral and composite analyses

  11. Atmospheric concentrations of persistent organic pollutants over the Pacific Ocean near southern Taiwan and the northern Philippines.

    Science.gov (United States)

    Chao, How-Ran; Lin, Ding-Yan; Chen, Kuang-Yu; Gou, Yan-Yu; Chiou, Tsyr-Huei; Lee, Wen-Jhy; Chen, Shui-Jen; Wang, Lin-Chi

    2014-09-01

    This study investigates the atmospheric occurrence of persistent organic pollutants (POPs) over the Pacific Ocean near southern Taiwan and the northern Philippines. We determined sixty-six compounds, including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DLPCBs), polybrominated diphenyl ethers (PBDEs), as well as polychlorinated diphenyl ethers (PCDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), and polybrominated biphenyls (PBBs), in air samples simultaneously collected from the offshore oceanic atmosphere (n=6) and over a rural area (n=2). We calculated the atmospheric World Health Organization 2005 toxic equivalency levels (WHO2005-TEQ), for the total dioxin-like POPs, including PCDD/Fs, DLPCBs, and PBDD/Fs, being 0.00612 pg WHO2005-TEQ/m(3) and 0.0138 pg WHO2005-TEQ/m(3) over the ocean and land, respectively. We found unexpected lower averaged atmospheric PBDE concentrations in the rural area (15.9 pg/m(3)) than over the ocean (31.1 pg/m(3)) due to higher levels of the BDE209 congener, although the difference was not statistically significant. We have compared and reported our field results with previously published datasets over the global oceans, which suggest PCBs and PBDEs are the dominant chemical contaminants in the global oceanic atmosphere among these halogenated POPs (e.g. PCBs and Σdi-hepta PBDEs could be found in the range of 0.09-48.7 and 8.07-94.0 pg/m(3), respectively, including our dataset). However, there are still very few investigations on the global atmospheric levels of PBDD/Fs, PCDEs and PBBs and our data sums to these earlier studies. Finally, we point out that the halogenated POPs originated from Taiwan or the continental East Asia which could easily reach remote ocean sites via atmospheric transport. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Two-component wind fields over ocean waves using atmospheric lidar and motion estimation algorithms

    Science.gov (United States)

    Mayor, S. D.

    2016-02-01

    Numerical models, such as large eddy simulations, are capable of providing stunning visualizations of the air-sea interface. One reason for this is the inherent spatial nature of such models. As compute power grows, models are able to provide higher resolution visualizations over larger domains revealing intricate details of the interactions of ocean waves and the airflow over them. Spatial observations on the other hand, which are necessary to validate the simulations, appear to lag behind models. The rough ocean environment of the real world is an additional challenge. One method of providing spatial observations of fluid flow is that of particle image velocimetry (PIV). PIV has been successfully applied to many problems in engineering and the geosciences. This presentation will show recent research results that demonstate that a PIV-style approach using pulsed-fiber atmospheric elastic backscatter lidar hardware and wavelet-based optical flow motion estimation software can reveal two-component wind fields over rough ocean surfaces. Namely, a recently-developed compact lidar was deployed for 10 days in March of 2015 in the Eureka, California area. It scanned over the ocean. Imagery reveal that breaking ocean waves provide copius amounts of particulate matter for the lidar to detect and for the motion estimation algorithms to retrieve wind vectors from. The image below shows two examples of results from the experiment. The left panel shows the elastic backscatter intensity (copper shades) under a field of vectors that was retrieved by the wavelet-based optical flow algorithm from two scans that took about 15 s each to acquire. The vectors, that reveal offshore flow toward the NW, were decimated for clarity. The bright aerosol features along the right edge of the sector scan were caused by ocean waves breaking on the beach. The right panel is the result of scanning over the ocean on a day when wave amplitudes ranged from 8-12 feet and whitecaps offshore beyond the

  13. Understanding the distinctively skewed and heavy tailed character of atmospheric and oceanic probability distributions

    Energy Technology Data Exchange (ETDEWEB)

    Sardeshmukh, Prashant D., E-mail: Prashant.D.Sardeshmukh@noaa.gov [CIRES, University of Colorado, Boulder, Colorado 80309 (United States); NOAA/Earth System Research Laboratory, Boulder, Colorado 80305 (United States); Penland, Cécile [NOAA/Earth System Research Laboratory, Boulder, Colorado 80305 (United States)

    2015-03-15

    The probability distributions of large-scale atmospheric and oceanic variables are generally skewed and heavy-tailed. We argue that their distinctive departures from Gaussianity arise fundamentally from the fact that in a quadratically nonlinear system with a quadratic invariant, the coupling coefficients between system components are not constant but depend linearly on the system state in a distinctive way. In particular, the skewness arises from a tendency of the system trajectory to linger near states of weak coupling. We show that the salient features of the observed non-Gaussianity can be captured in the simplest such nonlinear 2-component system. If the system is stochastically forced and linearly damped, with one component damped much more strongly than the other, then the strongly damped fast component becomes effectively decoupled from the weakly damped slow component, and its impact on the slow component can be approximated as a stochastic noise forcing plus an augmented nonlinear damping. In the limit of large time-scale separation, the nonlinear augmentation of the damping becomes small, and the noise forcing can be approximated as an additive noise plus a correlated additive and multiplicative noise (CAM noise) forcing. Much of the diversity of observed large-scale atmospheric and oceanic probability distributions can be interpreted in this minimal framework.

  14. Fast Atmosphere-Ocean Model Runs with Large Changes in CO2

    Science.gov (United States)

    Russell, Gary L.; Lacis, Andrew A.; Rind, David H.; Colose, Christopher; Opstbaum, Roger F.

    2013-01-01

    How does climate sensitivity vary with the magnitude of climate forcing? This question was investigated with the use of a modified coupled atmosphere-ocean model, whose stability was improved so that the model would accommodate large radiative forcings yet be fast enough to reach rapid equilibrium. Experiments were performed in which atmospheric CO2 was multiplied by powers of 2, from 1/64 to 256 times the 1950 value. From 8 to 32 times, the 1950 CO2, climate sensitivity for doubling CO2 reaches 8 C due to increases in water vapor absorption and cloud top height and to reductions in low level cloud cover. As CO2 amount increases further, sensitivity drops as cloud cover and planetary albedo stabilize. No water vapor-induced runaway greenhouse caused by increased CO2 was found for the range of CO2 examined. With CO2 at or below 1/8 of the 1950 value, runaway sea ice does occur as the planet cascades to a snowball Earth climate with fully ice covered oceans and global mean surface temperatures near 30 C.

  15. Secular trends and climate drift in coupled ocean-atmosphere general circulation models

    Science.gov (United States)

    Covey, Curt; Gleckler, Peter J.; Phillips, Thomas J.; Bader, David C.

    2006-02-01

    Coupled ocean-atmosphere general circulation models (coupled GCMs) with interactive sea ice are the primary tool for investigating possible future global warming and numerous other issues in climate science. A long-standing problem with such models is that when different components of the physical climate system are linked together, the simulated climate can drift away from observation unless constrained by ad hoc adjustments to interface fluxes. However, 11 modern coupled GCMs, including three that do not employ flux adjustments, behave much better in this respect than the older generation of models. Surface temperature trends in control run simulations (with external climate forcing such as solar brightness and atmospheric carbon dioxide held constant) are small compared with observed trends, which include 20th century climate change due to both anthropogenic and natural factors. Sea ice changes in the models are dominated by interannual variations. Deep ocean temperature and salinity trends are small enough for model control runs to extend over 1000 simulated years or more, but trends in some regions, most notably the Arctic, differ substantially among the models and may be problematic. Methods used to initialize coupled GCMs can mitigate climate drift but cannot eliminate it. Lengthy "spin-ups" of models, made possible by increasing computer power, are one reason for the improvements this paper documents.

  16. Dynamics and causalities of atmospheric and oceanic data identified by complex networks and Granger causality analysis

    Science.gov (United States)

    Charakopoulos, A. K.; Katsouli, G. A.; Karakasidis, T. E.

    2018-04-01

    Understanding the underlying processes and extracting detailed characteristics of spatiotemporal dynamics of ocean and atmosphere as well as their interaction is of significant interest and has not been well thoroughly established. The purpose of this study was to examine the performance of two main additional methodologies for the identification of spatiotemporal underlying dynamic characteristics and patterns among atmospheric and oceanic variables from Seawatch buoys from Aegean and Ionian Sea, provided by the Hellenic Center for Marine Research (HCMR). The first approach involves the estimation of cross correlation analysis in an attempt to investigate time-lagged relationships, and further in order to identify the direction of interactions between the variables we performed the Granger causality method. According to the second approach the time series are converted into complex networks and then the main topological network properties such as degree distribution, average path length, diameter, modularity and clustering coefficient are evaluated. Our results show that the proposed analysis of complex network analysis of time series can lead to the extraction of hidden spatiotemporal characteristics. Also our findings indicate high level of positive and negative correlations and causalities among variables, both from the same buoy and also between buoys from different stations, which cannot be determined from the use of simple statistical measures.

  17. Radiocarbon constraints on the glacial ocean circulation and its impact on atmospheric CO2

    Science.gov (United States)

    Skinner, L. C.; Primeau, F.; Freeman, E.; de la Fuente, M.; Goodwin, P. A.; Gottschalk, J.; Huang, E.; McCave, I. N.; Noble, T. L.; Scrivner, A. E.

    2017-01-01

    While the ocean’s large-scale overturning circulation is thought to have been significantly different under the climatic conditions of the Last Glacial Maximum (LGM), the exact nature of the glacial circulation and its implications for global carbon cycling continue to be debated. Here we use a global array of ocean–atmosphere radiocarbon disequilibrium estimates to demonstrate a ∼689±53 14C-yr increase in the average residence time of carbon in the deep ocean at the LGM. A predominantly southern-sourced abyssal overturning limb that was more isolated from its shallower northern counterparts is interpreted to have extended from the Southern Ocean, producing a widespread radiocarbon age maximum at mid-depths and depriving the deep ocean of a fast escape route for accumulating respired carbon. While the exact magnitude of the resulting carbon cycle impacts remains to be confirmed, the radiocarbon data suggest an increase in the efficiency of the biological carbon pump that could have accounted for as much as half of the glacial–interglacial CO2 change. PMID:28703126

  18. High variability of atmospheric mercury in the summertime boundary layer through the central Arctic Ocean.

    Science.gov (United States)

    Yu, Juan; Xie, Zhouqing; Kang, Hui; Li, Zheng; Sun, Chen; Bian, Lingen; Zhang, Pengfei

    2014-08-15

    The biogeochemical cycles of mercury in the Arctic springtime have been intensively investigated due to mercury being rapidly removed from the atmosphere. However, the behavior of mercury in the Arctic summertime is still poorly understood. Here we report the characteristics of total gaseous mercury (TGM) concentrations through the central Arctic Ocean from July to September, 2012. The TGM concentrations varied considerably (from 0.15 ng/m(3) to 4.58 ng/m(3)), and displayed a normal distribution with an average of 1.23 ± 0.61 ng/m(3). The highest frequency range was 1.0-1.5 ng/m(3), lower than previously reported background values in the Northern Hemisphere. Inhomogeneous distributions were observed over the Arctic Ocean due to the effect of sea ice melt and/or runoff. A lower level of TGM was found in July than in September, potentially because ocean emission was outweighed by chemical loss.

  19. Direct observations of atmosphere - sea ice - ocean interactions during Arctic winter and spring storms

    Science.gov (United States)

    Graham, R. M.; Itkin, P.; Granskog, M. A.; Assmy, P.; Cohen, L.; Duarte, P.; Doble, M. J.; Fransson, A.; Fer, I.; Fernandez Mendez, M.; Frey, M. M.; Gerland, S.; Haapala, J. J.; Hudson, S. R.; Liston, G. E.; Merkouriadi, I.; Meyer, A.; Muilwijk, M.; Peterson, A.; Provost, C.; Randelhoff, A.; Rösel, A.; Spreen, G.; Steen, H.; Smedsrud, L. H.; Sundfjord, A.

    2017-12-01

    To study the thinner and younger sea ice that now dominates the Arctic the Norwegian Young Sea ICE expedition (N-ICE2015) was launched in the ice-covered region north of Svalbard, from January to June 2015. During this time, eight local and remote storms affected the region and rare direct observations of the atmosphere, snow, ice and ocean were conducted. Six of these winter storms passed directly over the expedition and resulted in air temperatures rising from below -30oC to near 0oC, followed by abrupt cooling. Substantial snowfall prior to the campaign had already formed a snow pack of approximately 50 cm, to which the February storms contributed an additional 6 cm. The deep snow layer effectively isolated the ice cover and prevented bottom ice growth resulting in low brine fluxes. Peak wind speeds during winter storms exceeded 20 m/s, causing strong snow re-distribution, release of sea salt aerosol and sea ice deformation. The heavy snow load caused widespread negative freeboard; during sea ice deformation events, level ice floes were flooded by sea water, and at least 6-10 cm snow-ice layer was formed. Elevated deformation rates during the most powerful winter storms damaged the ice cover permanently such that the response to wind forcing increased by 60 %. As a result of a remote storm in April deformation processes opened about 4 % of the total area into leads with open water, while a similar amount of ice was deformed into pressure ridges. The strong winds also enhanced ocean mixing and increased ocean heat fluxes three-fold in the pycnocline from 4 to 12 W/m2. Ocean heat fluxes were extremely large (over 300 W/m2) during storms in regions where the warm Atlantic inflow is located close to surface over shallow topography. This resulted in very large (5-25 cm/day) bottom ice melt and in cases flooding due to heavy snow load. Storm events increased the carbon dioxide exchange between the atmosphere and ocean but also affected the pCO2 in surface waters

  20. Forecasting of rainfall using ocean-atmospheric indices with a fuzzy neural technique

    Science.gov (United States)

    Srivastava, Gaurav; Panda, Sudhindra N.; Mondal, Pratap; Liu, Junguo

    2010-12-01

    SummaryForecasting of rainfall is imperative for rainfed agriculture of arid and semi-arid regions of the world where agriculture consumes nearly 80% of the total water demand. Fuzzy-Ranking Algorithm (FRA) is used to identify the significant input variables for rainfall forecast. A case study is carried out to forecast monthly rainfall in India with several ocean-atmospheric predictor variables. Three different scenarios of ocean-atmospheric predictor variables are used as a set of possible input variables for rainfall forecasting model: (1) two climate indices, i.e. Southern Oscillation Index (SOI) and Pacific Decadal Oscillation Index (PDOI); (2) Sea Surface Temperature anomalies (SSTa) in the 5° × 5° grid points in Indian Ocean; and (3) both the climate indices and SSTa. To generate a set of possible input variables for these scenarios, we use climatic indices and the SSTa data with different lags between 1 and 12 months. Nonlinear relationship between identified inputs and rainfall is captured with an Artificial Neural Network (ANN) technique. A new approach based on fuzzy c-mean clustering is proposed for dividing data into representative subsets for training, testing, and validation. The results show that this proposed approach overcomes the difficulty in determining optimal numbers of clusters associated with the data division technique of self-organized map. The ANN model developed with both the climate indices and SSTa shows the best performance for the forecast of the monthly August rainfall in India. Similar approach can be applied to forecast rainfall of any period at selected climatic regions of the world where significant relationship exists between the rainfall and climate indices.

  1. Atmospheric transport of continentally derived organic material to the central Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Gagosian, R B; Peltzer, E T

    1986-01-01

    The organic geochemistry component of the Sea-Air Exchange Program was designed to determine the terrestrial and marine sources and to search for atmospheric transformation processes of oceanic aerosols from the major wind regimes of the Pacific Ocean. At Enewetak Atoll the distributions of the individual lipid compounds in aerosols require that there be a significant vascular plant source, almost certainly from Eurasia. Lipids associated with wind-eroded soil dust can reasonably account for all of the lipid classes detected in terms of expected concentrations and distributions and of the correlations with Al and /sup 210/Pb. The temporal variability observed for the C/sub 20/ aliphatic hydrocarbons, fatty alcohols, fatty acid salts and wax esters in aerosols observed at Enewetak is most likely due to the seasonality of dust storm activity in China and the seasonal changes in the large-scale wind fields over the Pacific. Atmospheric transformations and annual fluxes to the ocean of the lipid class compounds described above have been determined by using rainfall, aerosol and gas phase lipid concentration data. These data and previously reported aerosol data were used to estimate air-sea fluxes on an annual basis at Enewetak. Rain was determined to be the major mechanism. An empirical /sup 210/Pb-rain volume relation was developed, extended to organic compounds and used to provide more realistic annual flux estimates. Analysis of the scavenging ratios shows that the very low vapor pressure compounds expected to be in microcrystalline particles have rainout-washout behavior very similar to that found at Enewetak for clays. However, the lighter compounds show very high washout factor values that can be rationalized on the basis of their volatility.

  2. Intraseasonal variability in the atmosphere-ocean climate system. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Lau, William K.M. [NASA/Goddard Space Flight Center, Greenbelt, MD (United States). Lab. for Atmospheres; Waliser, Duane E. [California Institute of Technology, Pasadena, CA (United States). Earth Science and Technology Directorate, Jet Propulsion Laboratory

    2012-07-01

    This updated multi-author, comprehensive and authoritative review of intra-seasonal variability (ISV), has a balance of observation, theory and modeling and provides a single source of reference for all those interested in this important, multi-faceted natural phenomenon and its relation to major short-term climatic variations. All the original chapters are updated, where appropriate. The book opens with an overview of ISV and observations from an historical perspective. Successive chapters then deal with the role of ISV in monsoon variability in the South Asian, East Asian and South American monsoon regions, in North America and in the oceans. The coupling between ocean and atmosphere is considered, together with the function of angular momentum and Earth rotation. Later chapters deal with modeling ISV in the atmosphere and oceans, and the connection between the Madden and Julian Oscillation (MJO). Specifically updated in this second edition is the chapter on modeling with recent development in global high-resolution modeling of the fine structures of the MJO. The El Nino/Southern Oscillation with short-term climate change is also considered. The authors consider how knowledge of ISV may be harnessed into improving long range forecasts of severe weather, and a new chapter on substantial new development of ISV research is added. This includes five subject areas: a) new theories of the MJO; b) vertical structures of the MJO, including latent heating profile derived from satellite data; c) extratropical-tropical interaction associated with MJO; d) linkage of ISV to transport of biogeochemical species; and e) possible impact of ISV on West Africa and Middle East region. (orig.)

  3. Oasis in Iraq: Universities Flourish in Kurdistan

    Science.gov (United States)

    Krieger, Zvika

    2007-01-01

    The campus of Salahadin University--peaceful, bustling, and collegial-- is a rare sight in Iraq, where sectarian violence has brought the higher education system to the verge of collapse. Home to the country's historically repressed four million to five million ethnic Kurds, it is an oasis of stability and tranquility while much of the rest of…

  4. Oxygenated volatile organic carbon in the western Pacific convective center: ocean cycling, air-sea gas exchange and atmospheric transport

    Science.gov (United States)

    Schlundt, Cathleen; Tegtmeier, Susann; Lennartz, Sinikka T.; Bracher, Astrid; Cheah, Wee; Krüger, Kirstin; Quack, Birgit; Marandino, Christa A.

    2017-09-01

    A suite of oxygenated volatile organic compounds (OVOCs - acetaldehyde, acetone, propanal, butanal and butanone) were measured concurrently in the surface water and atmosphere of the South China Sea and Sulu Sea in November 2011. A strong correlation was observed between all OVOC concentrations in the surface seawater along the entire cruise track, except for acetaldehyde, suggesting similar sources and sinks in the surface ocean. Additionally, several phytoplankton groups, such as haptophytes or pelagophytes, were also correlated to all OVOCs, indicating that phytoplankton may be an important source of marine OVOCs in the South China and Sulu seas. Humic- and protein-like fluorescent dissolved organic matter (FDOM) components seemed to be additional precursors for butanone and acetaldehyde. The measurement-inferred OVOC fluxes generally showed an uptake of atmospheric OVOCs by the ocean for all gases, except for butanal. A few important exceptions were found along the Borneo coast, where OVOC fluxes from the ocean to the atmosphere were inferred. The atmospheric OVOC mixing ratios over the northern coast of Borneo were relatively high compared with literature values, suggesting that this coastal region is a local hotspot for atmospheric OVOCs. The calculated amount of OVOCs entrained into the ocean seemed to be an important source of OVOCs to the surface ocean. When the fluxes were out of the ocean, marine OVOCs were found to be enough to control the locally measured OVOC distribution in the atmosphere. Based on our model calculations, at least 0.4 ppb of marine-derived acetone and butanone can reach the upper troposphere, where they may have an important influence on hydrogen oxide radical formation over the western Pacific Ocean.

  5. Changes in the poleward energy flux by the atmosphere and ocean as a possible cause for ice ages

    Energy Technology Data Exchange (ETDEWEB)

    Newell, R E

    1974-01-01

    It is proposed that the two preferred modes of temperature and circulation of the atmosphere which occurred over the past 100,000 yr correspond to two modes of partitioning of the poleward energy flux between the atmosphere and ocean. At present the ocean carries an appreciable fraction of the transport, for example about three-eighths at 30/sup 0/N. In the cold mode it is suggested that the ocean carries less, and the atmosphere more, than at present. During the formation of the ice, at 50,000 BP, for example, the overall flux is expected to be slightly lower than at present and during melting, at 16,000 BP, slightly higher. The transition between the modes is seen as a natural imbalance in the atmosphere-ocean energy budget with a gradual warming of the ocean during an Ice Age eventually culminating in its termination. At the present the imbalance is thought to correspond to a natural cooling of the ocean, which will lead to the next Ice Age. The magnitude of temperature changes in the polar regions differ between the hemispheres in the same way as present seasonal changes, being larger in the northern than in the southern hemisphere. Overall the atmospheric energy cycle was more intense during the Ice Ages than now. Observational tests are proposed by which predictions from the present arguments may be compared with deductions about the environment of the past. Data used for the present state of the atmospheric general circulation are the latest global data available and contain no known major uncertainties. However, data for the oceanic circulation and energy budget are less well known for the present and almost unknown for the past. Hence the proposed imbalances must be treated as part of a speculative hypothesis, but one which eventually may be subject to observational test as no solar variability is invoked.

  6. Air-Sea Momentum and Enthalpy Exchange in Coupled Atmosphere-Wave-Ocean Modeling of Tropical Cyclones

    Science.gov (United States)

    Curcic, M.; Chen, S. S.

    2016-02-01

    The atmosphere and ocean are coupled through momentum, enthalpy, and mass fluxes. Accurate representation of these fluxes in a wide range of weather and climate conditions is one of major challenges in prediction models. Their current parameterizations are based on sparse observations in low-to-moderate winds and are not suited for high wind conditions such as tropical cyclones (TCs) and winter storms. In this study, we use the Unified Wave INterface - Coupled Model (UWIN-CM), a high resolution, fully-coupled atmosphere-wave-ocean model, to better understand the role of ocean surface waves in mediating air-sea momentum and enthalpy exchange in TCs. In particular, we focus on the explicit treatment of wave growth and dissipation for calculating atmospheric and oceanic stress, and its role in upper ocean mixing and surface cooling in the wake of the storm. Wind-wave misalignment and local wave disequilibrium result in difference between atmospheric and oceanic stress being largest on the left side of the storm. We find that explicit wave calculation in the coupled model reduces momentum transfer into the ocean by more than 10% on average, resulting in reduced cooling in TC's wake and subsequent weakening of the storm. We also investigate the impacts of sea surface temperature and upper ocean parameterization on air-sea enthalpy fluxes in the fully coupled model. High-resolution UWIN-CM simulations of TCs with various intensities and structure are conducted in this study to better understand the complex TC-ocean interaction and improve the representation of air-sea coupling processes in coupled prediction models.

  7. Coupled Atmosphere-Wave-Ocean Modeling of Tropical Cyclones: Progress, Challenges, and Ways Forward

    Science.gov (United States)

    Chen, Shuyi

    2015-04-01

    /s. It is found that the air-sea fluxes are quite asymmetric around a storm with complex features representing various air-sea interaction processes in TCs. A unique observation in Typhoon Fanapi is the development of a stable boundary layer in the near-storm cold wake region, which has a direct impact on TC inner core structure and intensity. Despite of the progress, challenges remain. Air-sea momentum exchange in wind speed greater than 30-40 m/s is largely unresolved. Directional wind-wave stress and wave-current stress are difficult to determine from observations. Effects of sea spray on the air-sea fluxes are still not well understood. This talk will provide an overview on progress made in recent years, challenges we are facing, and ways forward. An integrated coupled observational and atmosphere-wave-ocean modeling system is urgently needed, in which coupled model development and targeted observations from field campaign and lab measurements together form the core of the research and prediction system. Another important aspect is that fully coupled models provide explicit, integrated impact forecasts of wind, rain, waves, ocean currents and surges in TCs and winter storms, which are missing in most current NWP models. It requires a new strategy for model development, evaluation, and verification. Ensemble forecasts using high-resolution coupled atmosphere-wave-ocean models can provide probabilistic forecasts and quantitative uncertainty estimates, which also allow us to explore new methodologies to verify probabilistic impact forecasts and evaluate model physics using a stochastic approach. Examples of such approach in TCs including Superstorm Sandy will be presented.

  8. Cooperative aquatic sensing using the telesupervised adaptive ocean sensor fleet

    Science.gov (United States)

    Dolan, John M.; Podnar, Gregg W.; Stancliff, Stephen; Low, Kian Hsiang; Elfes, Alberto; Higinbotham, John; Hosler, Jeffrey; Moisan, Tiffany; Moisan, John

    2009-09-01

    Earth science research must bridge the gap between the atmosphere and the ocean to foster understanding of Earth's climate and ecology. Typical ocean sensing is done with satellites or in situ buoys and research ships which are slow to reposition. Cloud cover inhibits study of localized transient phenomena such as Harmful Algal Blooms (HAB). A fleet of extended-deployment surface autonomous vehicles will enable in situ study of characteristics of HAB, coastal pollutants, and related phenomena. We have developed a multiplatform telesupervision architecture that supports adaptive reconfiguration based on environmental sensor inputs. Our system allows the autonomous repositioning of smart sensors for HAB study by networking a fleet of NOAA OASIS (Ocean Atmosphere Sensor Integration System) surface autonomous vehicles. In situ measurements intelligently modify the search for areas of high concentration. Inference Grid and complementary information-theoretic techniques support sensor fusion and analysis. Telesupervision supports sliding autonomy from high-level mission tasking, through vehicle and data monitoring, to teleoperation when direct human interaction is appropriate. This paper reports on experimental results from multi-platform tests conducted in the Chesapeake Bay and in Pittsburgh, Pennsylvania waters using OASIS platforms, autonomous kayaks, and multiple simulated platforms to conduct cooperative sensing of chlorophyll-a and water quality.

  9. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from ISLAS ORCADAS in the North Atlantic Ocean from 1976-11-03 to 1976-12-18 (NCEI Accession 8100429)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains bottle cast data, collected by ISLAS ORCADAS SHIP (cruise 11) between November 3, 1976 to December 18, 1976, in the North Atlantic Ocean. This...

  10. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from POLARSTERN in the Arctic Ocean from 1993-08-10 to 1993-09-24 (NODC Accession 9600042)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Conductivity, Temperature and Depth (CTD); and other data were collected using ship POLARSTERN from Arctic Ocean. The data was collected from August 10, 1993 to...

  11. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from TUXPAN in the North Pacific Ocean from 1966-10-15 to 1967-08-27 (NODC Accession 9700073)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton, hydrochemical, and other data were collected from net and bottle casts from the Tuxpan in the North Pacific Ocean from 15 October 1966 to 27 August...

  12. Physical profile data collected during the calendar year 2003 for the Tropical Atmosphere Ocean Project by NOAA's Pacific Marine Environment Lab (NODC Accession 0001364)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical profile data were collected using meteorological sensors and CTD casts in the Northeast Pacific Ocean from NOAA Ship KA'IMIMOANA and NOAA Ship RONALD H....

  13. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from ISLAS ORCADAS in the North Atlantic Ocean from 1978-04-07 to 1978-05-21 (NCEI Accession 8100428)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This record contains bottle cast data, collected by ISLAS ORCADAS ship (cruise 16) in the North Atlantic Ocean. This data is in CTD-78 format (binary) and included...

  14. Recreational Value of an Oasis in Oman

    Science.gov (United States)

    Zekri, Slim; Mbaga, Msafiri; Fouzai, Ayoub; Al-Shaqsi, Saif

    2011-07-01

    Increasing demand for water to develop non-agricultural activities is causing water to be diverted to high-value uses at the expense of irrigation. However, agriculture provides a flow of amenities in the desert environment which are not either accounted or paid. Oases are spread all over the globe and are threatened for various reasons among which is the high pressure of demand for fresh water. This paper estimates the recreation use value of an oasis. The paper is based on the Misfat Al-Abryeen oasis in Oman, a man-made area of streams and woodland. The travel cost method is used through an on-site questionnaire distributed to 230 visitors. Around 75% of visitors to the oasis also visited other historical or ecological sites during the same day-trip. The econometric model is estimated using negative binomial regression with endogenous stratification. The average consumer surplus, or benefit, from visiting Misfat Al-Abryeen is estimated at US 104.74 per individual per trip. The total social benefit from this oasis is estimated at 366,590 per year. These results underscore the importance of the role played by irrigated agriculture in the provision of amenity services for the tourism sector in a desert environment. The sustainability of the irrigation activity depends on the recognition of the recreation role of oases and the transfer of part of these benefits to the farmers who maintain the irrigation system. The implementation of an entrance fee to the oasis might increase farmers' profit by 6-21%.

  15. Effects of Precipitation on Ocean Mixed-Layer Temperature and Salinity as Simulated in a 2-D Coupled Ocean-Cloud Resolving Atmosphere Model

    Science.gov (United States)

    Li, Xiaofan; Sui, C.-H.; Lau, K-M.; Adamec, D.

    1999-01-01

    A two-dimensional coupled ocean-cloud resolving atmosphere model is used to investigate possible roles of convective scale ocean disturbances induced by atmospheric precipitation on ocean mixed-layer heat and salt budgets. The model couples a cloud resolving model with an embedded mixed layer-ocean circulation model. Five experiment are performed under imposed large-scale atmospheric forcing in terms of vertical velocity derived from the TOGA COARE observations during a selected seven-day period. The dominant variability of mixed-layer temperature and salinity are simulated by the coupled model with imposed large-scale forcing. The mixed-layer temperatures in the coupled experiments with 1-D and 2-D ocean models show similar variations when salinity effects are not included. When salinity effects are included, however, differences in the domain-mean mixed-layer salinity and temperature between coupled experiments with 1-D and 2-D ocean models could be as large as 0.3 PSU and 0.4 C respectively. Without fresh water effects, the nocturnal heat loss over ocean surface causes deep mixed layers and weak cooling rates so that the nocturnal mixed-layer temperatures tend to be horizontally-uniform. The fresh water flux, however, causes shallow mixed layers over convective areas while the nocturnal heat loss causes deep mixed layer over convection-free areas so that the mixed-layer temperatures have large horizontal fluctuations. Furthermore, fresh water flux exhibits larger spatial fluctuations than surface heat flux because heavy rainfall occurs over convective areas embedded in broad non-convective or clear areas, whereas diurnal signals over whole model areas yield high spatial correlation of surface heat flux. As a result, mixed-layer salinities contribute more to the density differences than do mixed-layer temperatures.

  16. Antarctic Ice Sheet Discharge Driven by Atmosphere-Ocean Feedbacks Across the Last Glacial Termination

    Science.gov (United States)

    Fogwill, C. J.; Turney, C. S.; Golledge, N. R.; Etheridge, D. M.; Rubino, M.; Thornton, D.; Baker, A.; Weber, M. E.; Woodward, J.; van Ommen, T. D.; Moy, A. D.; Davies, S. M.; Bird, M. I.; Winter, K.; Munksgaard, N.; Menviel, L.; Rootes, C.; Vohra, J.; Rivera, A.; Cooper, A.

    2016-12-01

    Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000-11,650 yrs ago) allows us to identify ice-climate feedbacks that could improve future projections1,2. Whilst the sequence of events during this period are reasonably well-known, relatively poor chronological control has precluded precise alignment of ice, atmospheric and marine records2, making it difficult to assess relationships between Antarctic ice-sheet dynamics, climate change and sea-level rise3-5. Here we present results from a highly-resolved `horizontal ice core'6,7 from the Weddell Sea Embayment, which records millennial-scale ice-sheet dynamics across this extensive sector of Antarctica. Counterintuitively, we find ice-sheet surface drawdown of 600 m across the Antarctic Cold Reversal (ACR; 14,600-12,700 yrs ago)5, with stabilisation during the subsequent millennia of atmospheric warming. Earth system and ice-sheet modelling highlights that this response was likely sustained by strong ocean-ice feedbacks4,8; however, the drivers remain uncertain. Given the coincidence of the ice-sheet changes recorded with marked shifts in atmospheric circulation9,10,11we suggest that millennial-scale Antarctic ice-sheet behaviour was initiated and sustained by global atmospheric teleconnections across the LGT. This has important ramifications ice-sheet stability under contemporary climate change, with changing atmospheric and oceanic circulation patterns. 1 Collins, M. et al. in Climate Change 2013: The Physical Science Basis. 2 Weber, M. E. et al. Nature 510, 134-138, (2014). 3 Weaver, A. J., et al., Science 299, 1709-1713, (2003). 4 Golledge, N. R. et al. Nat Commun 5, (2014). 5 Pedro, J. B. et al. Nature Geosci9. 51-55 (2015). 6 Turney, C. S. M. et al. Journal of Quaternary Science 28, 697-704 (2013). 7 Winter, K. et al. Geophys. Res. Lett.43. 5. 2019-2026 (2016). 8 Menviel, L., A. et al., Quaternary Science Reviews 30, 1155-1172 (2011). 9 Hogg

  17. Atmospheric occurrence, transport and gas-particle partitioning of polychlorinated biphenyls over the northwestern Pacific Ocean

    Science.gov (United States)

    Wu, Zilan; Lin, Tian; Li, Zhongxia; Li, Yuanyuan; Guo, Tianfeng; Guo, Zhigang

    2017-10-01

    Ship-board air samples were collected during March to May 2015 from the East China Sea (ECS) to the northwestern Pacific Ocean (NWP) to explore the atmospheric occurrence and gas-particle partitioning of polychlorinated biphenyls (PCBs) when the westerly East Asian Monsoon prevailed. Total PCB concentrations in the atmosphere ranged from 56.8 to 261 pg m-3. Higher PCB levels were observed off the coast and minor temperature-induced changes showed that continuous emissions from East Asia remain as an important source to the regional atmosphere. A significant relationship between Koa (octanol-air partition coefficient) and KP (gas-particle partition coefficient) for PCBs was observed under continental air masses, suggesting that land-derived organic aerosols affected the PCB gas-particle partitioning after long-range transport, while an absence of this correlation was identified in marine air masses. The PCB partitioning cannot be fully explained by the absorptive mechanism as the predicted KP were found to be 2-3 orders of magnitude lower than the measured Kp, while the prediction was closely matched when soot adsorption was considered. The results suggested the importance of soot carbon as a transport medium for PCBs during their long-range transport and considerable impacts of continental outflows on PCBs across the downwind area. The estimated transport mass of particulate PCBs into the ECS and NWP totals 2333 kg during the spring, constituting ca. 17% of annual emission inventories of unintentionally produced PCB in China.

  18. Ice-dynamic projections of the Greenland ice sheet in response to atmospheric and oceanic warming

    Directory of Open Access Journals (Sweden)

    J. J. Fürst

    2015-05-01

    Full Text Available Continuing global warming will have a strong impact on the Greenland ice sheet in the coming centuries. During the last decade (2000–2010, both increased melt-water runoff and enhanced ice discharge from calving glaciers have contributed 0.6 ± 0.1 mm yr−1 to global sea-level rise, with a relative contribution of 60 and 40% respectively. Here we use a higher-order ice flow model, spun up to present day, to simulate future ice volume changes driven by both atmospheric and oceanic temperature changes. For these projections, the flow model accounts for runoff-induced basal lubrication and ocean warming-induced discharge increase at the marine margins. For a suite of 10 atmosphere and ocean general circulation models and four representative concentration pathway scenarios, the projected sea-level rise between 2000 and 2100 lies in the range of +1.4 to +16.6 cm. For two low emission scenarios, the projections are conducted up to 2300. Ice loss rates are found to abate for the most favourable scenario where the warming peaks in this century, allowing the ice sheet to maintain a geometry close to the present-day state. For the other moderate scenario, loss rates remain at a constant level over 300 years. In any scenario, volume loss is predominantly caused by increased surface melting as the contribution from enhanced ice discharge decreases over time and is self-limited by thinning and retreat of the marine margin, reducing the ice–ocean contact area. As confirmed by other studies, we find that the effect of enhanced basal lubrication on the volume evolution is negligible on centennial timescales. Our projections show that the observed rates of volume change over the last decades cannot simply be extrapolated over the 21st century on account of a different balance of processes causing ice loss over time. Our results also indicate that the largest source of uncertainty arises from the surface mass balance and the underlying climate change

  19. Structure of the marine atmospheric boundary layer over an oceanic thermal front: SEMAPHORE experiment

    Science.gov (United States)

    Kwon, B. H.; BéNech, B.; Lambert, D.; Durand, P.; Druilhet, A.; Giordani, H.; Planton, S.

    1998-10-01

    The Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, the third phase of which took place between October 4 and November 17, 1993, was conducted over the oceanic Azores Current located in the Azores basin and mainly marked at the surface by a thermal front due to the gradient of the sea surface temperature (SST) of about 1° to 2°C per 100 km. The evolution of the marine atmospheric boundary layer (MABL) over the SST front was studied with two aircraft and a ship in different meteorological conditions. For each case, the influence of the incoming air direction with respect to the orientation of the oceanic front was taken into account. During the campaign, advanced very high resolution radiometer pictures did not show any relation between the SST field and the cloud cover. The MABL was systematically thicker on the warm side than on the cold side. The mean MABL structure described from aircraft data collected in a vertical plane crossing the oceanic front was characterized by (1) an atmospheric horizontal gradient of 1° to 2°C per 100 km in the whole depth of the mixed layer and (2) an increase of the wind intensity from the cold to the warm side when the synoptic wind blew from the cold side. The surface sensible heat (latent heat) flux always increased from the cold to the warm sector owing to the increase of the wind and of the temperature (specific humidity) difference between the surface and the air. Turbulence increased from the cold to the warm side in conjunction with the MABL thickening, but the normalized profiles presented the same structure, regardless of the position over the SST front. In agreement with the Action de Recherche Programme te Petite Echelle and Grande Echelle model, the mean temperature and momentum budgets were highly influenced by the horizontal temperature gradient. In particular, the strong ageostrophic influence in the MABL above the SST front seems

  20. Biological and physical controls in the Southern Ocean on past millennial-scale atmospheric CO2 changes.

    Science.gov (United States)

    Gottschalk, Julia; Skinner, Luke C; Lippold, Jörg; Vogel, Hendrik; Frank, Norbert; Jaccard, Samuel L; Waelbroeck, Claire

    2016-05-17

    Millennial-scale climate changes during the last glacial period and deglaciation were accompanied by rapid changes in atmospheric CO2 that remain unexplained. While the role of the Southern Ocean as a 'control valve' on ocean-atmosphere CO2 exchange has been emphasized, the exact nature of this role, in particular the relative contributions of physical (for example, ocean dynamics and air-sea gas exchange) versus biological processes (for example, export productivity), remains poorly constrained. Here we combine reconstructions of bottom-water [O2], export production and (14)C ventilation ages in the sub-Antarctic Atlantic, and show that atmospheric CO2 pulses during the last glacial- and deglacial periods were consistently accompanied by decreases in the biological export of carbon and increases in deep-ocean ventilation via southern-sourced water masses. These findings demonstrate how the Southern Ocean's 'organic carbon pump' has exerted a tight control on atmospheric CO2, and thus global climate, specifically via a synergy of both physical and biological processes.

  1. Near 7-day response of ocean bottom pressure to atmospheric surface pressure and winds in the northern South China Sea

    Science.gov (United States)

    Zhang, Kun; Zhu, Xiao-Hua; Zhao, Ruixiang

    2018-02-01

    Ocean bottom pressures, observed by five pressure-recording inverted echo sounders (PIESs) from October 2012 to July 2014, exhibit strong near 7-day variability in the northern South China Sea (SCS) where long-term in situ bottom pressure observations are quite sparse. This variability was strongest in October 2013 during the near two years observation period. By joint analysis with European Center for Medium-Range Weather Forecasts (ECMWF) data, it is shown that the near 7-day ocean bottom pressure variability is closely related to the local atmospheric surface pressure and winds. Within a period band near 7 days, there are high coherences, exceeding 95% significance level, of observed ocean bottom pressure with local atmospheric surface pressure and with both zonal and meridional components of the wind. Ekman pumping/suction caused by the meridional component of the wind in particular, is suggested as one driving mechanism. A Kelvin wave response to the near 7-day oscillation would propagate down along the continental slope, observed at the Qui Nhon in the Vietnam. By multiple and partial coherence analyses, we find that local atmospheric surface pressure and Ekman pumping/suction show nearly equal influence on ocean bottom pressure variability at near 7-day periods. A schematic diagram representing an idealized model gives us a possible mechanism to explain the relationship between ocean bottom pressure and local atmospheric forcing at near 7-day periods in the northern SCS.

  2. Atmospheric and precipitation chemistry over the North Atlantic Ocean: Shipboard results, April-May 1984

    Science.gov (United States)

    Church, T. M.; Tramontano, J. M.; Whelpdale, D. M.; Andreae, M. O.; Galloway, J. N.; Keene, W. C.; Knap, A. H.; Tokos, J.

    1991-10-01

    During a North Atlantic cruise from Dakar, Senegal, to Woods Hole, Massachusetts (April 14-May 11, 1984), crossing the area of 14°-48°N; 17°-70°W, we collected atmospheric aerosols (C, N, S species), gases (SO4, HNO3, dimethyl sulfide (DMS), synthetic organic chemicals), and precipitation (major inorganic/organic ions, trace metals). Air masses that had not contacted land for over 5 days had a composition close to that from the remote marine atmosphere. Oxidation of biogenic DMS to SO4= aerosol accounted for most nss-SO4= in these air masses. Air masses that had transected densely populated North America (in the westerlies) or the Mediterranean/North Africa ( in the easterlies) within 2-5 days of being sampled over the North Atlantic were enriched in acid precursor compounds and synthetic hydrocarbons relative to air that had spent longer over the North Atlantic. Strong acids and trace metals were also elevated in precipitation. Air masses that had transected regions of strong emissions within the preceding 2 days had concentrations of atmospheric pollutants approaching those typically found in continental air masses. More frequent storm tracks between the Icelandic low and the Bermuda high favored transport of North American emissions northeasterly, toward Europe. Trajectory analyses suggested that air masses sampled off the northwest African coast had passed over the Mediterranean. Composition of the aerosol and precipitation of these air masses was also indicative of continental emissions, including biomass and petroleum burning. Transport and deposition of continental emissions to the North Atlantic were significantly influencing surface atmospheric and oceanic chemistry of this region.

  3. A study of atmospheric diffusion from the LANDSAT imagery. [pollution transport over the ocean

    Science.gov (United States)

    Dejesusparada, N. (Principal Investigator); Viswanadham, Y.; Torsani, J. A.

    1981-01-01

    LANDSAT multispectral scanner data of the smoke plumes which originated in eastern Cabo Frio, Brazil and crossed over into the Atlantic Ocean, are analyzed to illustrate how high resolution LANDSAT imagery can aid meteorologists in evaluating specific air pollution events. The eleven LANDSAT images selected are for different months and years. The results show that diffusion is governed primarily by water and air temperature differences. With colder water, low level air is very stable and the vertical diffusion is minimal; but water warmer than the air induces vigorous diffusion. The applicability of three empirical methods for determining the horizontal eddy diffusivity coefficient in the Gaussian plume formula was evaluated with the estimated standard deviation of the crosswind distribution of material in the plume from the LANDSAT imagery. The vertical diffusion coefficient in stable conditions is estimated using Weinstock's formulation. These results form a data base for use in the development and validation of meso scale atmospheric diffusion models.

  4. Laboratory modelling of the transfer processes between the ocean and atmosphere in the boundary layers

    Directory of Open Access Journals (Sweden)

    Sergeev Daniil

    2017-01-01

    Full Text Available The processes of momentum and heat transfer between ocean and atmosphere in the boundary layer were investigated within laboratory modeling for a wide range of wind speed and surface wave including hurricane conditions. Experiments were carried out on the Wind-Wave Flume of the Large Thermostratified Tank of IAP RAS. A special net located under the surface at different depths allows to vary parameters of surface waves independently on wind parameters. Theory of self-similarity of air flow parameters in the flume was used to calculate values aerodynamic and heat transfer coefficients from the measured velocity and temperature profiles by Pito and hotfilm gauges respectively. Simultaneous measurements of surface elevation with system wire allow to obtain spectra and integral parameters of waves. It was demonstrated that in contrast to the drag coefficient, heat transfer coefficient is virtually independent of wind speed and wave parameters to the moment of the beginning of spray generation and then increases rapidly.

  5. Treating Sample Covariances for Use in Strongly Coupled Atmosphere-Ocean Data Assimilation

    Science.gov (United States)

    Smith, Polly J.; Lawless, Amos S.; Nichols, Nancy K.

    2018-01-01

    Strongly coupled data assimilation requires cross-domain forecast error covariances; information from ensembles can be used, but limited sampling means that ensemble derived error covariances are routinely rank deficient and/or ill-conditioned and marred by noise. Thus, they require modification before they can be incorporated into a standard assimilation framework. Here we compare methods for improving the rank and conditioning of multivariate sample error covariance matrices for coupled atmosphere-ocean data assimilation. The first method, reconditioning, alters the matrix eigenvalues directly; this preserves the correlation structures but does not remove sampling noise. We show that it is better to recondition the correlation matrix rather than the covariance matrix as this prevents small but dynamically important modes from being lost. The second method, model state-space localization via the Schur product, effectively removes sample noise but can dampen small cross-correlation signals. A combination that exploits the merits of each is found to offer an effective alternative.

  6. Advection of pollutants by internal solitary waves in oceanic and atmospheric stable stratifications

    Directory of Open Access Journals (Sweden)

    G. W. Haarlemmer

    1998-01-01

    Full Text Available When a pollutant is released into the ocean or atmosphere under turbulent conditions, even a steady release is captured by large eddies resulting in localized patches of high concentration of the pollutant. If such a cloud of pollutant subsequently enters a stable stratification-either a pycnocline or thermocline-then internal waves are excited. Since large solitary internal waves have a recirculating core, pollutants may be trapped in the sclitary wave, and advected large distances through the waveguide provided by the stratification. This paper addresses the mechanisms, through computer and physical simulation, by which a localized release of a dense pollutant results in solitary waves that trap the pollutant or disperse the pollutant faster than in the absence of the waves.

  7. Atmosphere and ocean dynamics: contributors to the European Little Ice Age?

    Energy Technology Data Exchange (ETDEWEB)

    Palastanga, V.; Schrier, G. van der; Weber, S.L. [Royal Netherlands Meteorological Institute (KNMI), P.O. Box 201, De Bilt (Netherlands); Kleinen, T. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Max Planck Institute for Meteorology, Hamburg (Germany); Briffa, K.R.; Osborn, T.J. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom)

    2011-03-15

    The role of a reduction in the Atlantic meridional overturning and that of a persistently negative North Atlantic Oscillation in explaining the coldness of the European Little Ice Age (LIA) has been assessed in two sets of numerical experiments. These experiments are performed using an intermediate complexity climate model and a full complexity GCM. The reduction in the Meridional Overturning Circulation (MOC) of ca. 25% is triggered by a conventional fresh-water hosing set-up. A persistently negative NAO winter circulation, at NAO-index value -0.5, is imposed using recently developed data-assimilation techniques applicable on paleoclimatic timescales. The hosing experiments lead to a reduction in oceanic meridional heat transport and cooler sea-surface temperatures. Next to a direct cooling effect on European climate, the change in ocean surface temperatures feedback on the atmospheric circulation modifying European climate significantly. The data-assimilation experiments showed a reduction of winter temperatures over parts of Europe, but there is little persistence into the summer season. The output of all model experiments are compared to reconstructions of winter and summer temperature based on the available temperature data for the LIA period. This demonstrates that the hypothesis of a persistently negative NAO as an explanation for the European LIA does not hold. The hosing experiments do not clearly support the hypothesis that a reduction in the MOC is the primary driver of LIA climate change. However, a reduction in the Atlantic overturning might have been a cause of the European LIA climate, depending on whether there is a strong enough feedback on the atmospheric circulation. (orig.)

  8. Atmospheric trace elements in aerosols observed over the Southern Ocean and coastal East Antarctica

    Directory of Open Access Journals (Sweden)

    Guojie Xu

    2014-11-01

    Full Text Available Atmospheric aerosol samples were collected over the Southern Ocean (SO and coastal East Antarctica (CEA during the austral summer of 2010/11. Samples were analysed for trace elements, including Na, Mg, K, Al, Fe, Mn, Ni, Cd and Se, by inductively coupled plasma mass spectrometry (ICP-MS. The mean atmospheric concentrations over the SO were 1100 ng m−3 for Na, 190 ng m−3 for Mg, 150 ng m−3 for Al, 14 ng m−3 for Fe, 0.46 ng m−3 for Mn and 0.25 ng m−3 for Se. Over CEA, the mean concentrations were 990 ng m−3 for Na, 180 ng m−3 for Mg, 190 ng m−3 for Al, 26 ng m−3 for Fe, 0.70 ng m−3 for Mn and 0.29 ng m−3 for Se. Particle size distributions, enrichment factors (EFs and correlation analysis indicate that Na, Mg and K mainly came from the marine source, while Al, Fe and Mn were mainly from the crustal source, which also contributed to Mg and K over CEA. High EFs were associated with Ni, Cd and Se, suggesting likely contributions from mixed sources from the Antarctic continent, long-range transport, marine biogenic emissions and anthropogenic emissions. Sea-salt elements (Na, Mg, K were mainly accumulated in the coarse mode, and crustal elements (Al, Fe, Mn presented a bimodal size distribution pattern. Bioactive elements (Fe, Ni, Cd were enriched in the fine mode, especially with samples collected over the SO, possibly affecting biogeochemical cycles in this oceanic region.

  9. UNIFICATION AND APPLICATIONS OF MODERN OCEANIC/ATMOSPHERIC DATA ASSIMILATION ALGORITHMS

    Institute of Scientific and Technical Information of China (English)

    QIAO Fang-li; ZHANG Shao-qing; YUAN Ye-li

    2004-01-01

    The key mathematics and applications of various modern atmospheric/oceanic data assimilation methods including Optimal Interpolation(OI),4-dimensional variational approach(4D-Var)and filters were systematically reviewed and classified.Based on the data assimilation philosophy,I.e.,using model dynamics to extract the observational information,the common character of the problem,such as the probabilistic nature of the evolution of the atmospheric/oceanic system,noisy and irregularly spaced observations,and the advantages and disadvantages of these data assimilation algorithms,were discussed.In the filtering framework,all modern data assimilation algorithms were unified: OI/3D-Var is a stationary filter,4D-Var is a linear(Kalman)filter and an ensemble of Kalman filters is able to construct a nonlinear filter.The nonlinear filter such as the Ensemble Kalman Filter(ENKF),Ensemble Adjustment Kalman Filter(EAKF)and Ensemble Transformation Kalman Filter(ETKF)can,to some extent,account for the non-Gaussian information of the prior distribution from the model.The flow-dependent covariance estimated by an ensemble filter may be introduced to OI and 4D-Var to improve these traditional algorithms.In practice,the performance of algorithms may depend on the specific numerical model and the choice of algorithm may depend on the specific problem.However,the unification of algorithms allows us to establish a unified test system to evaluate these algorithms,which provides more insights into data assimilation philosophies and helps improve data assimilation techniques.

  10. Longitudinal Biases in the Seychelles Dome Simulated by 34 Ocean-Atmosphere Coupled General Circulation Models

    Science.gov (United States)

    Nagura, M.; Sasaki, W.; Tozuka, T.; Luo, J.; Behera, S. K.; Yamagata, T.

    2012-12-01

    The upwelling dome of the southern tropical Indian Ocean is examined by using simulated results from 34 ocean-atmosphere coupled general circulation models (CGCMs) including those from the phase five of the Coupled Model Intercomparison Project (CMIP5). Among the current set of the 34 CGCMs, 12 models erroneously produce the upwelling dome in the eastern half of the basin while the observed Seychelles Dome is located in the southwestern tropical Indian Ocean (Figure 1). The annual mean Ekman pumping velocity is almost zero in the southern off-equatorial region in these models. This is in contrast with the observations that show Ekman upwelling as the cause of the Seychelles Dome. In the models that produce the dome in the eastern basin, the easterly biases are prominent along the equator in boreal summer and fall that cause shallow thermocline biases along the Java and Sumatra coasts via Kelvin wave dynamics and result in a spurious upwelling dome there. In addition, these models tend to overestimate (underestimate) the magnitude of annual (semiannual) cycle of thermocline depth variability in the dome region, which is another consequence of the easterly wind biases in boreal summer-fall. Compared to the CMIP3 models (Yokoi et al. 2009), the CMIP5 models are even worse in simulating the dome longitudes and magnitudes of annual and semiannual cycles of thermocline depth variability in the dome region. Considering the increasing need to understand regional impacts of climate modes, these results may give serious caveats to interpretation of model results and help in further model developments.; Figure 1: The longitudes of the shallowest annual-mean D20 in 5°S-12°S. The open and filled circles are for the observations and the CGCMs, respectively.

  11. Land-atmosphere-ocean interactions in the southeastern Atlantic: interannual variability

    Science.gov (United States)

    Sun, Xiaoming; Vizy, Edward K.; Cook, Kerry H.

    2018-02-01

    Land-atmosphere-ocean interactions in the southeastern South Atlantic and their connections to interannual variability are examined using a regional climate model coupled with an intermediate-level ocean model. In austral summer, zonal displacements of the South Atlantic subtropical high (SASH) can induce variations of mixed-layer currents in the Benguela upwelling region through surface wind stress curl anomalies near the Namibian coast, and an eastward shifted SASH is related to the first Pacific-South American mode. When the SASH is meridionally displaced, mixed layer vertically-integrated Ekman transport anomalies are mainly a response to the change of alongshore surface wind stress. The latitudinal shift of the SASH tends to dampen the anomalous alongshore wind by modulating the land-sea thermal contrast, while opposed by oceanic diffusion. Although the position of the SASH is closely linked to the phase of El Niño-Southern Oscillation (ENSO) and the southern annular mode (SAM) in austral summer, an overall relationship between Benguela upwelling strength and ENSO or SAM is absent. During austral winter, variations of the mixed layer Ekman transport in the Benguela upwelling region are connected to the strength of the SASH through its impact on both coastal wind stress curl and alongshore surface wind stress. Compared with austral summer, low-level cloud cover change plays a more important role. Although wintertime sea surface temperature fluctuations in the equatorial Atlantic are strong and may act to influence variability over the northern Benguela area, the surface heat budget analysis suggests that local air-sea interactions dominate.

  12. Modeling of radiation transport in coupled atmosphere-snow-ice-ocean systems

    International Nuclear Information System (INIS)

    Stamnes, K.; Hamre, B.; Stamnes, J.J.; Ryzhikov, G.; Biryulina, M.; Mahoney, R.; Hauss, B.; Sei, A.

    2011-01-01

    A radiative transfer model for coupled atmosphere-snow-ice-ocean systems (CASIO-DISORT) is used to develop accurate and efficient tools for computing the bidirectional reflectance distribution function (BRDF) of sea ice for a wide range of situations occurring in nature. These tools include a method to generate sea ice inherent optical properties (IOPs: single-scattering albedo, extinction optical depth, and scattering asymmetry parameter) for any wavelength between 300 and 4000 nm as a function of sea ice physical parameters including real and imaginary parts of the sea ice refractive index, brine pocket concentration and effective brine pocket size, air bubble concentration and effective air bubble size, volume fraction of ice impurities and impurity absorption coefficient, and sea ice thickness. The CASIO-DISORT code was used to compute look-up tables (LUTs) of the Fourier expansion coefficients of the BRDF as a function of angles of illumination and observation, sea ice IOPs, and ocean albedo. By interpolation in the LUTs one efficiently obtains accurate BRDF values. To include snow on the ice we modified DISORT2 to accept Fourier expansion coefficients for the BDRF as input instead of the BRDF itself, thereby reducing the computation time by a factor of about 60. The BRDF computed by CASIO-DISORT or retrieved from the LUTs applies to diffuse light only. To remedy this shortcoming we added a specular Gaussian beam component to the new BRDF tool and verified that it works well for BRDFs for bare and snow-covered sea ice.

  13. Role of the oceans in the atmospheric cycle of carbonyl sulfide

    International Nuclear Information System (INIS)

    Johnson, J.E.

    1985-01-01

    Carbonyl sulfide (OCS) is both the dominant sulfur gas in the remote troposphere and, along with volcanoes, a major source of sulfur for the stratospheric sulfate layer. Prior to this work the ocean was regarded as a major sink for atmospheric OCS. The purpose of this study has been to assess the magnitude of the global air-sea flux of OCS. The author designed an analytical system which was centered around a Varian-3700 gas chromatograph with a flame-photometric detector. To increase the sensitivity of the detector, the hydrogen gas for the flame was doped with sulfur hexafluoride. Air samples were concentrated in a liquid nitrogen cooled freeze-out loop, then injected into the gas chromatograph. Water samples purged with sulfur-free zero-air which was analyzed similarly. He also built a permeation tube system for chemical standardization. This equipment was taken on two oceanographic cruises on the Pacific Ocean, one in the spring of 1983 and a second in the spring of 1983. Both of these cruises included measurements of air and seawater concentrations of OCS from the equator to the Aleutian Islands. The Henry's law constant of solubility for OCS was measured in the laboratory for filtered and boiled seawater at three temperatures

  14. Identification of Holocene millennial-scale forcing in the North Atlantic area: Ocean/atmosphere contribution

    Science.gov (United States)

    Debret, M.; Masson-Delmotte, V.; Christophe, C.; de Vernal, A.; Massei, N.; Eynaud, F.; Nicolle, M.; Frank, N.; Mary, Y.; Magny, M.

    2017-12-01

    Millennial (1500-year) cycles were evidenced decades ago from the advance and retreat of glaciers but many subsequent studies failed to demonstrate the unequivocal character of such oscillation from paleoclimate time series. Hence, the identification of a persistent 1500 year periodicity remains controversial both for the last glacial episode and the Holocene. Applying wavelet analysis to Holocene climate records, we have identified synchronous millennial-scale oscillations which permit to establish a North Atlantic millennial variability index (NAV-Index), maximum at 5330 ± 245, 3560 ± 190, 1810 ± 160 cal years BP and minimum at 4430 ± 250, 2640 ± 225 and 970 ± 200 years before present. This NAV-index was compared with the millennial variability of cosmogenic 10Be isotope, a proxy of solar activity. Differences between the two sets of records suggest that an internal mechanism (Ocean/atmosphere) must be at the origin of the North Atlantic millennial scale variability. Our data document an increased coherence and magnitude of the North Atlantic millennial variability since 6000 cal. years BP, with a frequency of 1780 ± 240 years. During the early Holocene, deglacial meltwater fluxes had strong regional impact and the coupling between subpolar gyre migration and Atlantic meridional oceanic circulation observed since afterward seems to be related to the end of the Laurentide and Inuitian ice sheet meltwater discharge. Hence, we may conclude that the evolution of this millennial oscillation in the future will depend upon the Greenland stability or melting.

  15. Coupled atmosphere-ocean-wave simulations of a storm event over the Gulf of Lion and Balearic Sea

    Science.gov (United States)

    Renault, Lionel; Chiggiato, Jacopo; Warner, John C.; Gomez, Marta; Vizoso, Guillermo; Tintore, Joaquin

    2012-01-01

    The coastal areas of the North-Western Mediterranean Sea are one of the most challenging places for ocean forecasting. This region is exposed to severe storms events that are of short duration. During these events, significant air-sea interactions, strong winds and large sea-state can have catastrophic consequences in the coastal areas. To investigate these air-sea interactions and the oceanic response to such events, we implemented the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System simulating a severe storm in the Mediterranean Sea that occurred in May 2010. During this event, wind speed reached up to 25 m.s-1 inducing significant sea surface cooling (up to 2°C) over the Gulf of Lion (GoL) and along the storm track, and generating surface waves with a significant height of 6 m. It is shown that the event, associated with a cyclogenesis between the Balearic Islands and the GoL, is relatively well reproduced by the coupled system. A surface heat budget analysis showed that ocean vertical mixing was a major contributor to the cooling tendency along the storm track and in the GoL where turbulent heat fluxes also played an important role. Sensitivity experiments on the ocean-atmosphere coupling suggested that the coupled system is sensitive to the momentum flux parameterization as well as air-sea and air-wave coupling. Comparisons with available atmospheric and oceanic observations showed that the use of the fully coupled system provides the most skillful simulation, illustrating the benefit of using a fully coupled ocean-atmosphere-wave model for the assessment of these storm events.

  16. Specificity of Atmosphere Correction of Satellite Ocean Color Data in Far-Eastern Region

    Science.gov (United States)

    Trusenkova, O.; Kachur, V.; Aleksanin, A. I.

    2016-02-01

    It was carried out an error analysis of satellite reflectance coefficients (Rrs) of MODIS/AQUA colour data for two atmospheric correction algorithms (NIR, MUMM) in the Far-Eastern region. Some sets of unique data of in situ and satellite measurements have been analysed. A set has some measurements with ASD spectroradiometer for each satellite pass. The measurement allocations were selected so the Chlorophyll-a concentration has high variability. Analysis of arbitrary set demonstrated that the main error component is systematic error, and it has simple relations on Rrs values. The reasons of such error behavior are considered. The most probable explanation of the large errors of oceanic color parameters in the Far-Eastern region is the ability of high concentrations of continental aerosol. A comparison of satellite and in situ measurements at AERONET stations of USA and South Korea regions has been made. It was shown that for NIR-correction of the atmosphere influence the error values in these two regions have differences up to 10 times for almost the same water turbidity and relatively good accuracy of computation of aerosol optical thickness. The study was supported by grant Russian Scientific Foundation No. 14-50-00034, by grant of Russian Foundation of Basic Research No.15-35-21032-mol-a-ved, and by Program of Basic Research "Far East" of Far Eastern Branch of Russian Academy of Sciences.

  17. Overview Kepuasan Pelanggan: Studi Kasus Pelayanan Rijstaffel di Restoran Oasis

    OpenAIRE

    Adiati, Maria Pia; Subakti, Agung Gita

    2015-01-01

    Rijstaffel service is not common found in fine dining restaurant in Indonesia. Oasis Restaurant in Jalan Raden Saleh, Jakarta, is a restaurant that is consistent in serving rijstaffel menu. The objective of this research is to analyze the level of consumer satisfaction and service quality in rijstaffel service at Oasis Restaurant. Research used qualitative method with library research by analyzing the questionnaire distributed by Oasis on Mei 2013 with 21 respondents. The result is the indica...

  18. OVERVIEW KEPUASAN PELANGGAN: STUDI KASUS PELAYANAN RIJSTAFFEL DI RESTORAN OASIS

    OpenAIRE

    Maria Pia Adiati; Agung Gita Subakti

    2015-01-01

    Rijstaffel service is not common found in fine dining restaurant in Indonesia. Oasis Restaurant in Jalan Raden Saleh, Jakarta, is a restaurant that is consistent in serving rijstaffel menu. The objective of this research is to analyze the level of consumer satisfaction and service quality in rijstaffel service at Oasis Restaurant. Research used qualitative method with library research by analyzing the questionnaire distributed by Oasis on Mei 2013 with 21 respondents. The result i...

  19. Geochemistry of the Nsuta Mn deposit in Ghana: Implications for the Paleoproterozoic atmosphere and ocean chemistry

    Science.gov (United States)

    Goto, K. T.; Ito, T.; Suzuki, K.; Kashiwabara, T.; Takaya, Y.; Shimoda, G.; Nozaki, T.; Kiyokawa, S.; Tetteh, G. M.; Nyame, F. K.

    2013-12-01

    Oxygenation of the atmosphere and oceans has influenced the evolution of ocean chemistry and diversification of early life. A number of large manganese (Mn) deposits are distributed in the Paleoproterozoic sedimentary successions that were formed during the great oxidation event (GOE) around 2.4-2.2 Ga (Meynard, 2010). Due to the high redox potential of Mn, occurrences of Mn deposits have been regarded as important evidence for a highly oxidized environment during the Paleoproterozoic (Kirschvink et al., 2000). Furthermore, because Mn oxides strongly adsorb various elements, including bioessential elements such as Mo, formation of large Mn deposits may have affected the seawater chemical composition and ecology during the Paleoproterozoic. However, the genesis of each Mn deposit is poorly constrained, and the relationships among the formation of Mn deposits, the evolution of atmospheric and ocean chemistry, and the diversification of early life are still ambiguous. In this study, we report the Re-Os isotope compositions, rare earth element (REE) compositions, and abundance of manganophile elements in the Mn carbonate ore and host sedimentary rock samples collected from the Nsuta Mn deposit of the Birimian Supergroup, Ghana. The Nsuta deposit is one of the largest Paleoproterozoic Mn deposits, although its genesis remains controversial (Melcher et al., 1995; Mucke et al., 1999). The composite Re-Os isochron age (2149 × 130 Ma) of the Mn carbonate and sedimentary rock samples was consistent with the depositional age of the sedimentary rocks (~2.2 Ga) presumed from the U-Pb zircon age of volcanic rocks (Hirdes and Davis, 1998), suggesting that the timing of Mn ore deposition was almost equivalent to the host rock sedimentation. The PAAS-normalized REE pattern showed a positive Eu anomaly in all samples and a positive Ce anomaly only in the Mn carbonate ore. These REE patterns indicate the possible contribution of Eu-enriched fluids derived from hydrothermal activity

  20. Numerical Methods in Atmospheric and Oceanic Modelling: The Andre J. Robert Memorial Volume

    Science.gov (United States)

    Rosmond, Tom

    Most people, even including some in the scientific community, do not realize how much the weather forecasts they use to guide the activities of their daily lives depend on very complex mathematics and numerical methods that are the basis of modern numerical weather prediction (NWP). André Robert (1929-1993), to whom Numerical Methods in Atmospheric and Oceanic Modelling is dedicated, had a career that contributed greatly to the growth of NWP and the role that the atmospheric computer models of NWP play in our society. There are probably no NWP models running anywhere in the world today that do not use numerical methods introduced by Robert, and those of us who work with and use these models everyday are indebted to him.The first two chapters of the volume are chronicles of Robert's life and career. The first is a 1987 interview by Harold Ritchie, one of Robert's many proteges and colleagues at the Canadian Atmospheric Environment Service. The interview traces Robert's life from his birth in New York to French Canadian parents, to his emigration to Quebec at an early age, his education and early employment, and his rise in stature as one of the preeminent research meteorologists of our time. An amusing anecdote he relates is his impression of weather forecasts while he was considering his first job as a meteorologist in the early 1950s. A newspaper of the time placed the weather forecast and daily horoscope side by side, and Robert regarded each to have a similar scientific basis. Thankfully he soon realized there was a difference between the two, and his subsequent career certainly confirmed the distinction.

  1. Ocean-atmosphere dynamics during Hurricane Ida and Nor'Ida: An application of the coupled ocean-;atmosphere–wave–sediment transport (COAWST) modeling system

    Science.gov (United States)

    Olabarrieta, Maitane; Warner, John C.; Armstrong, Brandy N.; Zambon, Joseph B.; He, Ruoying

    2012-01-01

    The coupled ocean–atmosphere–wave–sediment transport (COAWST) modeling system was used to investigate atmosphere–ocean–wave interactions in November 2009 during Hurricane Ida and its subsequent evolution to Nor'Ida, which was one of the most costly storm systems of the past two decades. One interesting aspect of this event is that it included two unique atmospheric extreme conditions, a hurricane and a nor'easter storm, which developed in regions with different oceanographic characteristics. Our modeled results were compared with several data sources, including GOES satellite infrared data, JASON-1 and JASON-2 altimeter data, CODAR measurements, and wave and tidal information from the National Data Buoy Center (NDBC) and the National Tidal Database. By performing a series of numerical runs, we were able to isolate the effect of the interaction terms between the atmosphere (modeled with Weather Research and Forecasting, the WRF model), the ocean (modeled with Regional Ocean Modeling System (ROMS)), and the wave propagation and generation model (modeled with Simulating Waves Nearshore (SWAN)). Special attention was given to the role of the ocean surface roughness. Three different ocean roughness closure models were analyzed: DGHQ (which is based on wave age), TY2001 (which is based on wave steepness), and OOST (which considers both the effects of wave age and steepness). Including the ocean roughness in the atmospheric module improved the wind intensity estimation and therefore also the wind waves, surface currents, and storm surge amplitude. For example, during the passage of Hurricane Ida through the Gulf of Mexico, the wind speeds were reduced due to wave-induced ocean roughness, resulting in better agreement with the measured winds. During Nor'Ida, including the wave-induced surface roughness changed the form and dimension of the main low pressure cell, affecting the intensity and direction of the winds. The combined wave age- and wave steepness

  2. A New Coupled Ocean-Waves-Atmosphere Model Designed for Tropical Storm Studies: Example of Tropical Cyclone Bejisa (2013-2014) in the South-West Indian Ocean

    Science.gov (United States)

    Pianezze, J.; Barthe, C.; Bielli, S.; Tulet, P.; Jullien, S.; Cambon, G.; Bousquet, O.; Claeys, M.; Cordier, E.

    2018-03-01

    Ocean-Waves-Atmosphere (OWA) exchanges are not well represented in current Numerical Weather Prediction (NWP) systems, which can lead to large uncertainties in tropical cyclone track and intensity forecasts. In order to explore and better understand the impact of OWA interactions on tropical cyclone modeling, a fully coupled OWA system based on the atmospheric model Meso-NH, the oceanic model CROCO, and the wave model WW3 and called MSWC was designed and applied to the case of tropical cyclone Bejisa (2013-2014). The fully coupled OWA simulation shows good agreement with the literature and available observations. In particular, simulated significant wave height is within 30 cm of measurements made with buoys and altimeters. Short-term (right place (in the eyewall of the tropical cyclone) and with the right size distribution, which is critical for cloud microphysics.

  3. Mercury in the atmosphere, snow and melt water ponds in the North Atlantic Ocean during Arctic summer.

    Science.gov (United States)

    Aspmo, Katrine; Temme, Christian; Berg, Torunn; Ferrari, Christophe; Gauchard, L Pierre-Alexis; Fain, Xavier; Wibetoe, Grethe

    2006-07-01

    Atmospheric mercury speciation measurements were performed during a 10 week Arctic summer expedition in the North Atlantic Ocean onboard the German research vessel RV Polarstern between June 15 and August 29, 2004. This expedition covered large areas of the North Atlantic and Arctic Oceans between latitudes 54 degrees N and 85 degrees N and longitudes 16 degrees W and 16 degrees E. Gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and mercury associated with particles (Hg-P) were measured during this study. In addition, total mercury in surface snow and meltwater ponds located on sea ice floes was measured. GEM showed a homogeneous distribution over the open North Atlantic Ocean (median 1.53 +/- 0.12 ng/m3), which is in contrast to the higher concentrations of GEM observed over sea ice (median 1.82 +/- 0.24 ng/m3). It is hypothesized that this results from either (re-) emission of mercury contained in snow and ice surfaces that was previously deposited during atmospheric mercury depletion events (AMDE) in the spring or evasion from the ocean due to increased reduction potential at high latitudes during Arctic summer. Measured concentrations of total mercury in surface snow and meltwater ponds were low (all samples RGM and Hg-P without a significant diurnal variability. These results indicate that the production and deposition of these reactive mercury species do not significantly contribute to the atmospheric mercury cycle in the North Atlantic Ocean during the Arctic summer.

  4. Seasonal Variations of the Earth's Gravitational Field: An Analysis of Atmospheric Pressure, Ocean Tidal, and Surface Water Excitation

    Science.gov (United States)

    Dong, D,; Gross, R.S.; Dickey, J.

    1996-01-01

    Monthly mean gravitational field parameters (denoted here as C(sub even)) that represent linear combinations of the primarily even degree zonal spherical harmonic coefficients of the Earth's gravitational field have been recovered using LAGEOS I data and are compared with those derived from gridded global surface pressure data of the National meteorological center (NMC) spanning 1983-1992. The effect of equilibrium ocean tides and surface water variations are also considered. Atmospheric pressure and surface water fluctuations are shown to be the dominant cause of observed annual C(sub even) variations. Closure with observations is seen at the 1sigma level when atmospheric pressure, ocean tide and surface water effects are include. Equilibrium ocean tides are shown to be the main source of excitation at the semiannual period with closure at the 1sigma level seen when both atmospheric pressure and ocean tide effects are included. The inverted barometer (IB) case is shown to give the best agreement with the observation series. The potential of the observed C(sub even) variations for monitoring mass variations in the polar regions of the Earth and the effect of the land-ocean mask in the IB calculation are discussed.

  5. Continuous flow IRMS application to CH4, MNHCS, and N2O in the atmosphere and the oceans

    International Nuclear Information System (INIS)

    Yoshida, N.; Tsunogai, U.; Toyoda, S.

    2001-01-01

    The application of CF-IRMS to measurement of methane (CH4), non-methane hydrocarbons (NMHCS), and nitrous oxide (N 2 O) is outlined and preliminary information on isotopic variations in the atmosphere and oceans is presented. Labelling of these compounds is expected to provide a robust method for tracing sources, sinks and controlling processes in the environment. (author)

  6. Collaborative project. Ocean-atmosphere interaction from meso-to planetary-scale. Mechanisms, parameterization, and variability

    Energy Technology Data Exchange (ETDEWEB)

    Small, Richard [National Center for Atmospheric Research, Boulder, CO (United States); Bryan, Frank [National Center for Atmospheric Research, Boulder, CO (United States); Tribbia, Joseph [National Center for Atmospheric Research, Boulder, CO (United States); Park, Sungsu [National Center for Atmospheric Research, Boulder, CO (United States); Dennis, John [National Center for Atmospheric Research, Boulder, CO (United States); Saravanan, R. [National Center for Atmospheric Research, Boulder, CO (United States); Schneider, Niklas [National Center for Atmospheric Research, Boulder, CO (United States); Kwon, Young-Oh [National Center for Atmospheric Research, Boulder, CO (United States)

    2015-06-11

    This project aims to improve long term global climate simulations by resolving ocean mesoscale activity and the corresponding response in the atmosphere. The main computational objectives are; i) to perform and assess Community Earth System Model (CESM) simulations with the new Community Atmospheric Model (CAM) spectral element dynamical core; ii) use static mesh refinement to focus on oceanic fronts; iii) develop a new Earth System Modeling tool to investigate the atmospheric response to fronts by selectively filtering surface flux fields in the CESM coupler. The climate research objectives are 1) to improve the coupling of ocean fronts and the atmospheric boundary layer via investigations of dependency on model resolution and stability functions: 2) to understand and simulate the ensuing tropospheric response that has recently been documented in observations: and 3) to investigate the relationship of ocean frontal variability to low frequency climate variability and the accompanying storm tracks and extremes in high resolution simulations. This is a collaborative multi-institution project consisting of computational scientists, climate scientists and climate model developers. It specifically aims at DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation.

  7. Observations of Recent Arctic Sea Ice Volume Loss and Its Impact on Ocean-Atmosphere Energy Exchange and Ice Production

    Science.gov (United States)

    Kurtz, N. T.; Markus, T.; Farrell, S. L.; Worthen, D. L.; Boisvert, L. N.

    2011-01-01

    Using recently developed techniques we estimate snow and sea ice thickness distributions for the Arctic basin through the combination of freeboard data from the Ice, Cloud, and land Elevation Satellite (ICESat) and a snow depth model. These data are used with meteorological data and a thermodynamic sea ice model to calculate ocean-atmosphere heat exchange and ice volume production during the 2003-2008 fall and winter seasons. The calculated heat fluxes and ice growth rates are in agreement with previous observations over multiyear ice. In this study, we calculate heat fluxes and ice growth rates for the full distribution of ice thicknesses covering the Arctic basin and determine the impact of ice thickness change on the calculated values. Thinning of the sea ice is observed which greatly increases the 2005-2007 fall period ocean-atmosphere heat fluxes compared to those observed in 2003. Although there was also a decline in sea ice thickness for the winter periods, the winter time heat flux was found to be less impacted by the observed changes in ice thickness. A large increase in the net Arctic ocean-atmosphere heat output is also observed in the fall periods due to changes in the areal coverage of sea ice. The anomalously low sea ice coverage in 2007 led to a net ocean-atmosphere heat output approximately 3 times greater than was observed in previous years and suggests that sea ice losses are now playing a role in increasing surface air temperatures in the Arctic.

  8. THE ATMOSPHERIC CYCLING AND AIR-SEA EXCHANGE OF MERCURY SPECIES IN THE SOUTH AND EQUATORIAL ATLANTIC OCEAN. (R829796)

    Science.gov (United States)

    Measurements of gas-, particle- and precipitation-phases of atmospheric mercury(Hg) were made in the South and equatorial Atlantic Ocean as part of the 1996IOC Trace Metal Baseline Study (Montevideo, Uruguay to Barbados). Total gaseousmercury (TGM) ranged from ...

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

    Digital Repository Service at National Institute of Oceanography (India)

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

    and the corresponding atmospheric circulation over this region has profound influence on the global weather and climate. In the past, several authors have made important contributions in the form of atlases mostly using ship data (Baumgartner and Reichel, 1975... available to interested users for non-commercial scientific research. For details of how to access the fields see: http:// www.mpimet.mpg.de/Depts/Physik/HOAPS. 1 Chapter I Introduction Oceans play a very important role in the global climate system...

  10. Ertel Potential Vorticity versus Bernoulli Streamfunction in Earth's Southern Ocean: Comparison with the Atmospheres of Earth, Mars, Jupiter and Saturn

    Science.gov (United States)

    Dowling, Timothy E.; Stanley, Geoff; Bradley, Mary Elizabeth; Marshall, David P.

    2017-10-01

    We are working to expand the comparative planetology of vorticity-streamfunction correlations established for the atmospheres of Earth, Mars, Jupiter and Saturn to include Earth’s Antarctic Circumpolar Current (ACC), which is the only oceanic jet that encircles the planet. Interestingly, the ACC and its eddies scale like atmospheric jets and eddies on Jupiter and Saturn---the Southern Ocean is a “giant planet” with a zonal jet stream. Our input is the Southern Ocean State Estimate (SOSE; Mazloff et al 2010, J. Phys. Ocean. 40, 880-899), an optimal combination of observations and primitive-equation model that spans 2005-2010. Two hurdles not encountered in atmospheric work arise from the nonlinear equation of state of ocean water: non-zero helicity, which prevents the existence of truly neutral (analogous to adiabatic) surfaces, and the lack of a geostrophic streamfunction in general. We follow de Szoeke et al (2000, J. Phys. Ocean. 30, 2830-2852) to overcome these hurdles, regionally, by using orthobaric density as the vertical coordinate. In agreement with results for all atmospheres analyzed to date, scatter plots of Ertel potential vorticity, Q, versus Bernoulli streamfunction, B, on orthobaric density surfaces in the Southern Ocean are well correlated. The general shape of the correlation is like a hockey stick, with the “blade” corresponding to a broad horizontal region that spans the ACC, and the “handle” corresponding to shallow water. The same linear-regression Q versus B model employed for Mars is applied to the ACC (“blade”) signal. Results include that the deeper water on the equatorward side of the ACC is most prone to shear instability, and elsewhere the ACC is “supersonic” such that the net propagation of vorticity waves is eastward, not the usual westward. During the 6-year span of the SOSE data, there is a steady drift of the correlation to larger values at the top of the vertical profile, and to smaller values in the middle of

  11. Disentangling the Roles of Atmospheric and Oceanic Forcing on the Last Deglaciation of the Greenland Ice Sheet

    Science.gov (United States)

    Keisling, B. A.; Deconto, R. M.

    2017-12-01

    Today the Greenland Ice Sheet loses mass via both oceanic and atmospheric processes. However, the relative importance of these mass balance components is debated, especially their potential impact on ongoing and future mass imbalance. Discerning the impact of oceanic versus atmospheric forcing during past periods of mass loss provides potential insight into the future behavior of the ice sheet. Here we present an ensemble of Greenland Ice Sheet simulations of the last deglaciation, designed to assess separately the roles of the ocean and the atmosphere in driving mass loss over the last twenty thousand years. We use twenty-eight different ocean forcing scenarios along with a cutting-edge reconstruction of time-evolving atmospheric conditions based on climate model output and δ15N-based temperature reconstructions to generate a range of ice-sheet responses during the deglaciation. We then compare the simulated timing of ice-retreat in individual catchments with estimates based on both 10Be (exposure) and 14C (minimum-limiting) dates. These experiments allow us to identify the ocean forcing scenario that best match the data on a local-to-regional (i.e., 100-1000 km) scales, providing an assessment of the relative importance of ocean and atmospheric forcing components around the periphery of Greenland. We use these simulations to quantify the importance of the three major mass balance terms (calving, oceanic melting, and surface melting) and assess the uncertainty of the relative influence of these factors during the most recent periods of major ice loss. Our results show that mass balance components around different sectors of the ice sheet respond differently to forcing, with oceanic components driving the majority of retreat in south and east Greenland and atmospheric forcing dominating in west and north Greenland In addition, we target three areas at high spatial resolution ( 1 km) around Greenland currently undergoing substantial change (Jakobshavn, Petermann

  12. Impact of resolving the diurnal cycle in an ocean-atmosphere GCM. Pt. 1: a diurnally forced OGCM

    Energy Technology Data Exchange (ETDEWEB)

    Bernie, D.J. [University of Reading, National Centre for Atmospheric Science - Climate, Department of Meteorology, Reading (United Kingdom); Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, IPSL, Paris (France); Met Office Hadley Centre, Exeter, EX1 3PB (United Kingdom); Guilyardi, E. [University of Reading, National Centre for Atmospheric Science - Climate, Department of Meteorology, Reading (United Kingdom); Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, IPSL, Paris (France); Madec, G. [Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, IPSL, Paris (France); Slingo, J.M.; Woolnough, S.J. [University of Reading, National Centre for Atmospheric Science - Climate, Department of Meteorology, Reading (United Kingdom)

    2007-11-15

    The diurnal cycle is a fundamental time scale in the climate system, at which the upper ocean and atmosphere are routinely observed to vary. Current climate models, however, are not configured to resolve the diurnal cycle in the upper ocean or the interaction of the ocean and atmosphere on these time scales. This study examines the diurnal cycle of the tropical upper ocean and its climate impacts. In the present paper, the first of two, a high vertical resolution ocean general circulation model (OGCM), with modified physics, is developed which is able to resolve the diurnal cycle of sea surface temperature (SST) and current variability in the upper ocean. It is then validated against a satellite derived parameterization of diurnal SST variability and in-situ current observations. The model is then used to assess rectification of the intraseasonal SST response to the Madden-Julian oscillation (MJO) by the diurnal cycle of SST. Across the equatorial Indo-Pacific it is found that the diurnal cycle increases the intraseasonal SST response to the MJO by around 20%. In the Pacific, the diurnal cycle also modifies the exchange of momentum between equatorially divergent Ekman currents and the meridionally convergent geostrophic currents beneath, resulting in a 10% increase in the strength of the Ekman cells and equatorial upwelling. How the thermodynamic and dynamical impacts of the diurnal cycle effect the mean state, and variability, of the climate system cannot be fully investigated in the constrained design of ocean-only experiments presented here. The second part of this study, published separately, addresses the climate impacts of the diurnal cycle in the coupled system by coupling the OGCM developed here to an atmosphere general circulation model. (orig.)

  13. A Unified Air-Sea Interface in Fully Coupled Atmosphere-Wave-Ocean Models for Data Assimilation and Ensemble Prediction

    Science.gov (United States)

    Chen, Shuyi; Curcic, Milan; Donelan, Mark; Campbell, Tim; Smith, Travis; Chen, Sue; Allard, Rick; Michalakes, John

    2014-05-01

    The goals of this study are to 1) better understand the physical processes controlling air-sea interaction and their impact on coastal marine and storm predictions, 2) explore the use of coupled atmosphere-ocean observations in model verification and data assimilation, and 3) develop a physically based and computationally efficient coupling at the air-sea interface that is flexible for use in a multi-model system and portable for transition to the next generation research and operational coupled atmosphere-wave-ocean-land models. We have developed a unified air-sea interface module that couples multiple atmosphere, wave, and ocean models using the Earth System Modeling Framework (ESMF). This standardized coupling framework allows researchers to develop and test air-sea coupling parameterizations and coupled data assimilation, and to better facilitate research-to-operation activities. It also allows for future ensemble forecasts using coupled models that can be used for coupled data assimilation and assessment of uncertainties in coupled model predictions. The current component models include two atmospheric models (WRF and COAMPS), two ocean models (HYCOM and NCOM), and two wave models (UMWM and SWAN). The coupled modeling systems have been tested and evaluated using the coupled air-sea observations (e.g., GPS dropsondes and AXBTs, drifters and floats) collected in recent field campaigns in the Gulf of Mexico and tropical cyclones in the Atlantic and Pacific basins. This talk will provide an overview of the unified air-sea interface model and fully coupled atmosphere-wave-ocean model predictions over various coastal regions and tropical cyclones in the Pacific and Atlantic basins including an example from coupled ensemble prediction of Superstorm Sandy (2012).

  14. An atmosphere-ocean GCM modelling study of the climate response to changing Arctic seaways in the early Cenozoic.

    Science.gov (United States)

    Roberts, C. D.; Legrande, A. N.; Tripati, A. K.

    2008-12-01

    The report of fossil Azolla (a freshwater aquatic fern) in sediments from the Lomonosov Ridge suggests low salinity conditions occurred in the Arctic Ocean in the early Eocene. Restricted passages between the Arctic Ocean and the surrounding oceans are hypothesized to have caused this Arctic freshening. We investigate this scenario using a water-isotope enabled atmosphere-ocean general circulation model with Eocene boundary conditions including 4xCO2, 7xCH4, altered bathymetry and topography, and an estimated distribution of Eocene vegetational types. In one experiment, oceanic exchange between the Arctic Ocean and other ocean basins was restricted to two shallow (~250 m) seaways, one in the North Atlantic, the Greenland-Norwegian seaway, and the second connecting the Arctic Ocean with the Tethys Ocean, the Turgai Straits. In the restricted configuration, the Greenland-Norwegian seaway was closed and exchange through the Turgai Straits was limited to a depth of ~60 m. The simulations suggest that the severe restriction of Arctic seaways in the early Eocene may have been sufficient to freshen Arctic Ocean surface waters, conducive to Azolla blooms. When exchange with the Arctic Ocean is limited, salinities in the upper several hundred meters of the water column decrease by ~10 psu. In some regions, surface salinity is within 2-3 psu of the reported maximum modern conditions tolerated by Azolla (~5 psu). In the restricted scenario, salt is stored preferentially in the North Atlantic and Tethys oceans, resulting in enhanced meridional overturning, increased poleward heat transport in the North Atlantic western boundary current, and warming of surface and intermediate waters in the North Atlantic by several degrees. Increased sensible and latent heat fluxes from the North Atlantic Ocean, combined with a reduction in cloud albedo, also lead to an increase in surface air temperature of over much of North America, Greenland and Eurasia. Our work is consistent with

  15. Using Real-Time Oceanic and Atmospheric Data in the Classroom

    Science.gov (United States)

    Culbertson, Britta

    2014-05-01

    While serving as an Einstein Fellow at the National Oceanic and Atmospheric Administration (NOAA), I conducted a research project based on the question, "How can science teachers use real-time oceanic and atmospheric data in their classrooms?" In the United States, new national science standards called the Next Generation Science Standards (NGSS) have been created. These standards provide more emphasis on the analysis of data and on modeling than previous state or national standards. Teachers are more tech-savvy than ever before and the internet provides free access to numerous scientific datasets. These data are useful when teachers have limited time and/or equipment to have students conduct their own experiments. However, the time it takes for practicing educators, even those with a scientific background, to understand how to access these data and use them in a meaningful way is a huge barrier. I wanted to find a way for teachers to make use of this readily available information and to create an online community where educators share best practices and lesson examples. I began by researching all of the websites hosted by NOAA that provide free, online access to real-time scientific data. I sorted the sites into categories based on their ease of usability for the non-scientist (e.g. teachers and their students). I gave several presentations on the use of real-time data in the classroom to teachers at National Science Teachers Association conferences and gathered teacher feedback on the successes and struggles of using data in the classroom. I began researching best practices for data use with the ultimate goal of creating a framework for matching available datasets from NOAA to the Next Generation Science Standards. After working on a NOAA research vessel, I developed a lesson using online data from the Alaska Fisheries Science Center Groundfish Survey. The overarching questions for this lesson are "How can pre-existing, large datasets help science students to

  16. Geophysical excitation of LOD/UT1 estimated from the output of the global circulation models of the atmosphere - ERA-40 reanalysis and of the ocean - OMCT

    Science.gov (United States)

    Korbacz, A.; Brzeziński, A.; Thomas, M.

    2008-04-01

    We use new estimates of the global atmospheric and oceanic angular momenta (AAM, OAM) to study the influence on LOD/UT1. The AAM series was calculated from the output fields of the atmospheric general circulation model ERA-40 reanalysis. The OAM series is an outcome of global ocean model OMCT simulation driven by global fields of the atmospheric parameters from the ERA- 40 reanalysis. The excitation data cover the period between 1963 and 2001. Our calculations concern atmospheric and oceanic effects in LOD/UT1 over the periods between 20 days and decades. Results are compared to those derived from the alternative AAM/OAM data sets.

  17. Ocean-Ice-Atmosphere Interactions off Sabrina and Adelie Coasts During NBP1402 and AU1402

    Science.gov (United States)

    Orsi, A. H.; Zielinski, N. J.; Webb, C.; Huber, B. A.

    2015-12-01

    Diverse interactions of winds, currents and ice around Antarctica dictate how, where and when the world's densest waters form, massive floating ice shelves and glaciers melt, gases are exchanged at the sea surface, and primary productivity. Compelled by recent rate estimates of East Antarctic Ice Sheet mass loss, we contrast the paths and mixing histories of oceanic waters reaching the continental ice edge off the Sabrina and Adelie coasts relying on a the first synoptic shipboard measurements made by U.S. (NBP1402) and Australian (AU1402) scientists. Analysis of historical hydrography and sea ice concentration fields within the Mertz Polynya indicates the apparent effect of evolving ocean-ice- atmosphere interactions on the characteristics of local Shelf Water (SW) sources. A polynya dominated water mass structure similar to that observed off the Adelie Coast before the removal of the Mertz Ice Tongue was expected to the west of the Dalton Ice Tongue (DIT). However, there was no evidence of dense SW off Sabrina Coast during both summer cruises of 2014 and 2015, thus lessening the region's preconceived influence to global meridional overturning. Present sea ice production within the eastern Dalton Polynya is overshadowed by freshwater input to relatively stable interior upper waters. The Antarctic Coastal Current (ACoC) picks up distinct meltwater contributions along the DIT western flank and in front of the Moscow University Ice Shelf (MUIS) and Totten Glacier (TG). Unlike over other highly influential margins to global sea level rise, the main evidence of inflow and mixing of relatively warm oceanic waters is reduced to relatively cold thermocline water (< 0.3°C) from the continental slope. This source water enters the eastern trough off Sabrina Coast and is swiftly steered poleward by complex underlying topography. Meltwater export from beneath the MUIS and TG is observed at newly discovered trenches that effectively constrain sub-cavity inflow to low salinity

  18. Onboard measurement system of atmospheric carbon monoxide over the Pacific Ocean by voluntary observing ships

    Science.gov (United States)

    Nara, H.; Tanimoto, H.; Nojiri, Y.; Mukai, H.; Machida, T.; Tohjima, Y.

    2011-07-01

    Long-term monitoring of carbon monoxide (CO) mixing ratios in the atmosphere over the Pacific Ocean is being carried out on commercial cargo vessels participating in the National Institute for Environmental Studies Voluntary Observing Ships program. The program provides a regular platform for measurement of atmospheric CO along four cruising routes: from Japan to Oceania, from Japan to the United States, from Japan to Canada, and from Japan to Southeast Asia. Flask samples are collected during every cruise for subsequent analysis in the laboratory, and in 2005, continuous shipboard CO measurements were initiated on three of the routes. Here, we describe the system we developed for onboard measurement of CO mixing ratios with a commercially available gas filter correlation CO analyzer. The fully automated system measures CO in ambient air, and the detector sensitivity and background signals are calibrated by referencing the measurements to a CO-in-air standard gas (~1 ppmv) and to CO-free air scrubbed with a catalyst, respectively. We examined the artificial production of CO in the high-pressure working gas standards (CO balanced with purified air at ppmv levels) during storage by referencing the measurements to CO standard gases maintained as our primary scale before and after use on the ships. The onboard performance of the continuous CO measurement system was evaluated by comparing its data with data from laboratory analyses of flask samples using gas chromatography with a reduction gas detector. The reasonably good consistency between the two independent measurement methods demonstrated the good performance of both methods over the course of 3-5 yr. The continuous measurement system was more useful than the flask sampling method for regionally polluted air masses, which were often encountered on Southeast Asian cruises.

  19. LOSCAR: Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model v2.0.4

    Directory of Open Access Journals (Sweden)

    R. E. Zeebe

    2012-01-01

    Full Text Available The LOSCAR model is designed to efficiently compute the partitioning of carbon between ocean, atmosphere, and sediments on time scales ranging from centuries to millions of years. While a variety of computationally inexpensive carbon cycle models are already available, many are missing a critical sediment component, which is indispensable for long-term integrations. One of LOSCAR's strengths is the coupling of ocean-atmosphere routines to a computationally efficient sediment module. This allows, for instance, adequate computation of CaCO3 dissolution, calcite compensation, and long-term carbon cycle fluxes, including weathering of carbonate and silicate rocks. The ocean component includes various biogeochemical tracers such as total carbon, alkalinity, phosphate, oxygen, and stable carbon isotopes. LOSCAR's configuration of ocean geometry is flexible and allows for easy switching between modern and paleo-versions. We have previously published applications of the model tackling future projections of ocean chemistry and weathering, pCO2 sensitivity to carbon cycle perturbations throughout the Cenozoic, and carbon/calcium cycling during the Paleocene-Eocene Thermal Maximum. The focus of the present contribution is the detailed description of the model including numerical architecture, processes and parameterizations, tuning, and examples of input and output. Typical CPU integration times of LOSCAR are of order seconds for several thousand model years on current standard desktop machines. The LOSCAR source code in C can be obtained from the author by sending a request to loscar.model@gmail.com.

  20. Characteristics of Atmosphere-Ocean CO2 Exchange due to Typhoon Activities over the East Asian Region

    Science.gov (United States)

    Lee, G.; Cho, C. H.; Lim, D. H.; Sun, M.; Lee, J.; Byun, Y. H.; Lee, J.

    2014-12-01

    Although the oceans are generally known as a net carbon sink in global sense, it is expected that CO₂release from oceans can occur locally depending on specific weather. This study addresses investigation of change in CO2 exchange between atmosphere and ocean due to typhoon activities, using "Carbon Tracker-Asia (CTA)". The CTA has constructed and managed at National Institute of Meteorological Research(NIMR) based on Carbon Tracker developed by NOAA. In order to examine effect of typhoon on change in air-sea CO2 exchange, we selected several cases which typhoon approached to Korean peninsula in the summertime and their tracks are similar to each other. Also, we analyzed difference between CO2 flux along typhoon tracks and other adjacent region not to be directly affected by typhoon in these cases. There is a difference in ocean fluxes around 15 gC/m²yr over strong typhoon areas compared to other areas. This difference varied with the wind speeds, the correlation coefficient between the ocean and the wind flux was found 0.7. Changes in carbon flux to affect the concentration of CO₂ in the atmosphere near surface instantly.

  1. The stability of the thermohaline circulation in a coupled ocean-atmosphere general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Schiller, A. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Mikolajewicz, U. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Voss, R. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)

    1996-02-01

    The stability of the Atlantic thermohaline circulation against meltwater input is investigated in a coupled ocean-atmosphere general circulation model. The meltwater input to the Labrador Sea is increased linearly for 250 years to a maximum input of 0.625 Sv and then reduced again to 0 (both instantaneously and slowly decreasing over 250 years). The resulting freshening forces a shutdown of the formation of North Atlantic deepwater and a subsequent reversal of the thermohaline circulation of the Atlantic, filling the deep Atlantic with Antarctic bottom water. The change in the overturning pattern causes a drastic reduction of the Atlantic northward heat transport, resulting in a strong cooling with maximum amplitude over the northern North Atlantic and a southward shift of the sea-ice margin in the Atlantic. Due to the increased meridional temperature gradient, the Atlantic intertropical convergence zone is displaced southward and the westerlies in the northern hemisphere gain strength. We identify four main feedbacks affecting the stability of the thermohaline circulation: the change in the overturning circulation of the Atlantic leads to longer residence times of the surface waters in high northern latitudes, which allows them to accumulate more precipitation and runoff from the continents, which results in an increased stability in the North Atlantic.

  2. Instability of combined gravity-inertial-Rossby waves in atmospheres and oceans

    Directory of Open Access Journals (Sweden)

    J. F. McKenzie

    2011-06-01

    Full Text Available The properties of the instability of combined gravity-inertial-Rossby waves on a β-plane are investigated. The wave-energy exchange equation shows that there is an exchange of energy with the background stratified medium. The energy source driving the instability lies in the background enthalpy released by the gravitational buoyancy force. It is shown that if the phase speed of the westward propagating low frequency-long wavelength Rossby wave exceeds the Poincaré-Kelvin (or "equivalent" shallow water wave speed, instability arises from the merging of Rossby and Poincaré modes. There are two key parameters in this instability condition; namely, the equatorial/rotational Mach (or Froude number M and the latitude θ0 of the β-plane. In general waves equatorward of a critical latitude for given M can be driven unstable, with corresponding growth rates of the order of a day or so. Although these conclusions may only be safely drawn for short wavelengths corresponding to a JWKB wave packet propagating internally and located far from boundaries, nevertheless such a local instability may play a significant role in atmosphere-ocean dynamics.

  3. Simulations of future climate with a coupled atmosphere-ocean general circulation model

    International Nuclear Information System (INIS)

    Stendel, M.; Schmith, T.; Hesselbjerg Christensen, J.

    2001-01-01

    A coupled atmosphere/ocean general circulation model to study the time-dependent climate response to changing concentrations of greenhouse gases, chlorofluorocarbons and aerosols according to the new IPCC SRES scenarios A2 and B2 has been used. The results of these experiments are compared to an unforced 300-year control experiment. The changes in the last three decades of the scenario simulations (2071-2100) are furthermore compared to the simulation of present-day climate (1961-1990). In accordance with previous experiments we find that greenhouse warming is reduced when aerosol effects are considered. Sulfur emissions, however, are lower than in the IS92a scenario. Consequently, the greenhouse warming effect, which leads to a bigger temperature increase than in the GSDIO experiment can outweigh the aerosol cooling effect. The result shows that there still are serious difficulties and uncertainties in this type of model simulation. Those are partially due to oversimplifications in the model, concerning the radiative properties of aerosols in particular, and therefore the indirect aerosol effect. Another inherent problem, however, is the uncertainty in the scenarios themselves. This is the case for short-lived substances with an inhomogeneous spatial and temporal distribution, such as aerosols. Therefore, on a decadal horizon, changes in the emissions of those substance can exert a significant effect on anthropogenic climate change. (LN)

  4. Ocean-atmosphere forcing of centennial hydroclimatic variability in the Pacific Northwest

    Science.gov (United States)

    Steinman, Byron A.; Abbott, Mark B.; Mann, Michael E.; Ortiz, Joseph D.; Feng, Song; Pompeani, David P.; Stansell, Nathan D.; Anderson, Lesleigh; Finney, Bruce P.; Bird, Broxton W.

    2014-01-01

    Reconstructing centennial timescale hydroclimate variability during the late Holocene is critically important for understanding large-scale patterns of drought and their relationship with climate dynamics. We present sediment oxygen isotope records spanning the last two millennia from 10 lakes, as well as climate model simulations, indicating that the Little Ice Age was dry relative to the Medieval Climate Anomaly in much of the Pacific Northwest of North America. This pattern is consistent with observed associations between the El Niño Southern Oscillation (ENSO), the Northern Annular Mode and drought as well as with proxy-based reconstructions of Pacific ocean-atmosphere variations over the past 1000 years. The large amplitude of centennial variability indicated by the lake data suggests that regional hydroclimate is characterized by longer-term shifts in ENSO-like dynamics, and that an improved understanding of the centennial timescale relationship between external forcing and drought conditions is necessary for projecting future hydroclimatic conditions in western North America.

  5. Monte Carlo climate change forecasts with a global coupled ocean-atmosphere model

    International Nuclear Information System (INIS)

    Cubasch, U.; Santer, B.D.; Hegerl, G.; Hoeck, H.; Maier-Reimer, E.; Mikolajwicz, U.; Stoessel, A.; Voss, R.

    1992-01-01

    The Monte Carlo approach, which has increasingly been used during the last decade in the field of extended range weather forecasting, has been applied for climate change experiments. Four integrations with a global coupled ocean-atmosphere model have been started from different initial conditions, but with the same greenhouse gas forcing according to the IPCC scenario A. All experiments have been run for a period of 50 years. The results indicate that the time evolution of the global mean warming depends strongly on the initial state of the climate system. It can vary between 6 and 31 years. The Monte Carlo approach delivers information about both the mean response and the statistical significance of the response. While the individual members of the ensemble show a considerable variation in the climate change pattern of temperature after 50 years, the ensemble mean climate change pattern closely resembles the pattern obtained in a 100 year integration and is, at least over most of the land areas, statistically significant. The ensemble averaged sea-level change due to thermal expansion is significant in the global mean and locally over wide regions of the Pacific. The hydrological cycle is also significantly enhanced in the global mean, but locally the changes in precipitation and soil moisture are masked by the variability of the experiments. (orig.)

  6. Analysis of runoff for the Baltic basin with an integrated Atmospheric-Ocean-Hydrology Model

    Directory of Open Access Journals (Sweden)

    K.-G. Richter

    2006-01-01

    Full Text Available A fully integrated Atmospheric-Ocean-Hydrology Model (BALTIMOS = Baltic Integrated Model System has been developed using existing model components. Experiment and model design has been adapted to the Baltic basin with a catchment area of approximately 1 750 000 km2. A comprehensive model validation has been completed using large meteorological and hydrological measurement database. Comparing the calculated runoff from the integrated and non-integrated model system with measurements for three different representative subbasins and the entire Baltic basin, the effect of the integrated model is described. The results display a good agreement between measured and calculated runoff. The effect of the integrated model is rather negligible looking at computed mean values: There is no significant difference between mean monthly runoff of the integrated and non-integrated model during the year with the exception of spring. There is a delay of one month with regard to peak runoff for the non-integrated model in spring caused by different interactive processes during the melting period.

  7. Estimating the marine signal in the near infrared for atmospheric correction of satellite ocean-color imagery over turbid waters

    Science.gov (United States)

    Bourdet, Alice; Frouin, Robert J.

    2014-11-01

    The classic atmospheric correction algorithm, routinely applied to second-generation ocean-color sensors such as SeaWiFS, MODIS, and MERIS, consists of (i) estimating the aerosol reflectance in the red and near infrared (NIR) where the ocean is considered black (i.e., totally absorbing), and (ii) extrapolating the estimated aerosol reflectance to shorter wavelengths. The marine reflectance is then retrieved by subtraction. Variants and improvements have been made over the years to deal with non-null reflectance in the red and near infrared, a general situation in estuaries and the coastal zone, but the solutions proposed so far still suffer some limitations, due to uncertainties in marine reflectance modeling in the near infrared or difficulty to extrapolate the aerosol signal to the blue when using observations in the shortwave infrared (SWIR), a spectral range far from the ocean-color wavelengths. To estimate the marine signal (i.e., the product of marine reflectance and atmospheric transmittance) in the near infrared, the proposed approach is to decompose the aerosol reflectance in the near infrared to shortwave infrared into principal components. Since aerosol scattering is smooth spectrally, a few components are generally sufficient to represent the perturbing signal, i.e., the aerosol reflectance in the near infrared can be determined from measurements in the shortwave infrared where the ocean is black. This gives access to the marine signal in the near infrared, which can then be used in the classic atmospheric correction algorithm. The methodology is evaluated theoretically from simulations of the top-of-atmosphere reflectance for a wide range of geophysical conditions and angular geometries and applied to actual MODIS imagery acquired over the Gulf of Mexico. The number of discarded pixels is reduced by over 80% using the PC modeling to determine the marine signal in the near infrared prior to applying the classic atmospheric correction algorithm.

  8. Sensitivity of open-water ice growth and ice concentration evolution in a coupled atmosphere-ocean-sea ice model

    Science.gov (United States)

    Shi, Xiaoxu; Lohmann, Gerrit

    2017-09-01

    A coupled atmosphere-ocean-sea ice model is applied to investigate to what degree the area-thickness distribution of new ice formed in open water affects the ice and ocean properties. Two sensitivity experiments are performed which modify the horizontal-to-vertical aspect ratio of open-water ice growth. The resulting changes in the Arctic sea-ice concentration strongly affect the surface albedo, the ocean heat release to the atmosphere, and the sea-ice production. The changes are further amplified through a positive feedback mechanism among the Arctic sea ice, the Atlantic Meridional Overturning Circulation (AMOC), and the surface air temperature in the Arctic, as the Fram Strait sea ice import influences the freshwater budget in the North Atlantic Ocean. Anomalies in sea-ice transport lead to changes in sea surface properties of the North Atlantic and the strength of AMOC. For the Southern Ocean, the most pronounced change is a warming along the Antarctic Circumpolar Current (ACC), owing to the interhemispheric bipolar seasaw linked to AMOC weakening. Another insight of this study lies on the improvement of our climate model. The ocean component FESOM is a newly developed ocean-sea ice model with an unstructured mesh and multi-resolution. We find that the subpolar sea-ice boundary in the Northern Hemisphere can be improved by tuning the process of open-water ice growth, which strongly influences the sea ice concentration in the marginal ice zone, the North Atlantic circulation, salinity and Arctic sea ice volume. Since the distribution of new ice on open water relies on many uncertain parameters and the knowledge of the detailed processes is currently too crude, it is a challenge to implement the processes realistically into models. Based on our sensitivity experiments, we conclude a pronounced uncertainty related to open-water sea ice growth which could significantly affect the climate system sensitivity.

  9. Impact of resolving the diurnal cycle in an ocean-atmosphere GCM. Pt. 2. A diurnally coupled CGCM

    Energy Technology Data Exchange (ETDEWEB)

    Bernie, D.J. [Met Office Hadley Centre, Exeter (United Kingdom); University of Reading, National Centre for Atmospheric Science-Climate, Department of Meteorology, Reading (United Kingdom); Numeriques, IPSL, Laboratoire d' Oceanographie et du Climat, Experimentation et Approches, Paris (France); Guilyardi, E. [University of Reading, National Centre for Atmospheric Science-Climate, Department of Meteorology, Reading (United Kingdom); Numeriques, IPSL, Laboratoire d' Oceanographie et du Climat, Experimentation et Approches, Paris (France); Madec, G. [Numeriques, IPSL, Laboratoire d' Oceanographie et du Climat, Experimentation et Approches, Paris (France); Slingo, J.M.; Woolnough, S.J.; Cole, J. [University of Reading, National Centre for Atmospheric Science-Climate, Department of Meteorology, Reading (United Kingdom)

    2008-12-15

    Coupled ocean atmosphere general circulation models (GCM) are typically coupled once every 24 h, excluding the diurnal cycle from the upper ocean. Previous studies attempting to examine the role of the diurnal cycle of the upper ocean and particularly of diurnal SST variability have used models unable to resolve the processes of interest. In part 1 of this study a high vertical resolution ocean GCM configuration with modified physics was developed that could resolve the diurnal cycle in the upper ocean. In this study it is coupled every 3 h to atmospheric GCM to examine the sensitivity of the mean climate simulation and aspects of its variability to the inclusion of diurnal ocean-atmosphere coupling. The inclusion of the diurnal cycle leads to a tropics wide increase in mean sea surface temperature (SST), with the strongest signal being across the equatorial Pacific where the warming increases from 0.2 C in the central and western Pacific to over 0.3 C in the eastern equatorial Pacific. Much of this warming is shown to be a direct consequence of the rectification of daily mean SST by the diurnal variability of SST. The warming of the equatorial Pacific leads to a redistribution of precipitation from the Inter tropical convergence zone (ITCZ) toward the equator. In the western Pacific there is an increase in precipitation between Papa new guinea and 170 E of up to 1.2 mm/day, improving the simulation compared to climatology. Pacific sub tropical cells are increased in strength by about 10%, in line with results of part 1 of this study, due to the modification of the exchange of momentum between the equatorially divergent Ekman currents and the geostropic convergence at depth, effectively increasing the dynamical response of the tropical Pacific to zonal wind stresses. During the spring relaxation of the Pacific trade winds, a large diurnal cycle of SST increases the seasonal warming of the equatorial Pacific. When the trade winds then re-intensify, the increase in

  10. Concentrations and (delta)13C values of atmospheric CO2 from oceanic atmosphere through time: polluted and non-polluted areas

    International Nuclear Information System (INIS)

    Longinelli, Antonio; Selmo, Enrico; Lenaz, Renzo; Ori, Carlo

    2005-01-01

    CO 2 is one of the primary agents of global climate changes. The increase of atmospheric CO 2 concentration is essentially related to human-induced emissions and, particularly, to the burning of fossil fuel whose (delta) 13 C values are quite negative. Consequently, an increase of the CO 2 concentration in the atmosphere should be paralleled by a decrease of its (delta) 13 C. Continuous and/or spot measurements of CO 2 concentrations were repeatedly carried out during the last decade and in the same period of the year along hemispheric courses from Italy to Antarctica on a vessel of the Italian National Research Program in Antarctica. During these expeditions, discrete air samples were also collected in 4-l Pyrex flasks in order to carry out precise carbon isotope analyses on atmospheric CO 2 from different areas, including theoretically 'clean' open ocean areas, with the main purpose of comparing these open ocean results with the results obtained by the National Oceanic and Atmospheric Administration/World Meteorological Organization (NOAA/WMO) at land-based stations. According to the data obtained for these two variables, a relatively large atmospheric pollution is apparent in the Mediterranean area where the CO 2 concentration has reached the value of 384 ppmv while quite negative (delta) 13 C values have been measured only occasionally. In this area, southerly winds probably help to reduce the effect of atmospheric pollution even though, despite a large variability of CO 2 concentrations, these values are consistently higher than those measured in open ocean areas by a few ppmv to about 10 ppmv. A marked, though non-continuous, pollution is apparent in the area of the Bab-el-Mandeb strait where (delta) 13 C values considerably more negative than in the Central and Southern Red Sea were measured. The concentration of atmospheric CO 2 over the Central Indian Ocean increased from about 361 ppmv at the end of 1996 to about 373 ppmv at the end of 2003 (mean growth

  11. Trace-Element Evidence for an Aqueous Atmospheric Origin of Desert Varnish: implications for the aqueous atmospheric input flux into the ocean

    Science.gov (United States)

    Thiagarajan, N.; Lee, C.

    2003-12-01

    Desert varnish is a slow-growing dark patina commonly found on rock surfaces in arid environments. Varnishes consist of about 30% Mn and Fe oxides accompanied by oxides of Si, Al, Mg, K and Ca, which occur primarily in the form of clays. Although it is generally agreed that varnishes have an atmospheric origin, their exact formation mechanism remains highly debated. Two endmember hypotheses are gradual accumulation of wind-blown dust followed by diagenesis, and direct chemical precipitation of dissolved elements from atmospheric aerosols. To rule out one of these hypotheses, we investigated the trace-element systematics of varnishes, in particular, focusing on those elements that have contrasting solubilities in aqueous environments. If our trace element analyses are consistent with the varnishes being derived from dissolved atmospheric constituents then the data can be used to quantify the paleofluxes of the soluble fraction of atmospheric aerosols to various depositional environments. For example, this will have implications for the transport of metals to the ocean that are immediately biologically available. We collected varnishes deposited on smooth basaltic lava flow surfaces in the Cima Volcanic Field (Mojave Desert) and in Death Valley, California. The chosen lava flows retain original flow surface structure and are topographical highs; the effects of erosion are hence minimal. Varnishes were scraped off with a quartz rod to minimize trace element contamination and the trace element compositions were then determined by ICP-MS using an external synthetic standard for calibration. Our analyses show that the rare-earth elements (REEs), Co, Ni, and Pb are enriched 1.5 to 10 times relative to the upper continental crust (UCC) and that Nb, Ti, Ta, Hf, Th, Rb and Cs are depleted to varying degrees relative to UCC and the REEs. These fractionations can be explained by their differing chemical behaviors in aqueous environments. The extreme depletion in Rb and Cs

  12. Fates, Budgets, and Health Implications of Macondo Spill Volatile Hydrocarbons in the Ocean and Atmosphere of the Gulf of Mexico

    Science.gov (United States)

    Leifer, I.; Barletta, B.; Blake, D. R.; Blake, N. J.; Bradley, E. S.; Meinardi, S.; Lehr, B.; Luyendyk, B. P.; Roberts, D. A.; Rowland, F. S.

    2010-12-01

    The Macondo Oil Spill released unprecedented oil and gas to the ocean, estimated at 63000 bbl/day, which dispersed and dissolved during rise (Technical Flow Rate Team Report, 2010); yet, most of the oil reached the sea surface as oil slicks that then evolved due to weathering and dispersant application (Mass Balance Report, 2010). Remote sensing (near infrared imaging spectrometry) allowed quantification of thick surface oil, values of which were incorporated into an overall oil budget calculation. Remote sensing data, atmospheric samples, and numerical modeling, strongly suggest significant volatile loss during rise, yet measured atmospheric concentrations were high. Scaling atmospheric measurements to the total oil spill implies very high, extensive, and persistent levels of atmospheric petroleum hydrocarbon exposure with strong health implications to on-site workers and to coastal residents from wind advection.

  13. Direct night-time ejection of particle-phase reduced biogenic sulfur compounds from the ocean to the atmosphere.

    Science.gov (United States)

    Gaston, Cassandra J; Furutani, Hiroshi; Guazzotti, Sergio A; Coffee, Keith R; Jung, Jinyoung; Uematsu, Mitsuo; Prather, Kimberly A

    2015-04-21

    The influence of oceanic biological activity on sea spray aerosol composition, clouds, and climate remains poorly understood. The emission of organic material and gaseous dimethyl sulfide (DMS) from the ocean represents well-documented biogenic processes that influence particle chemistry in marine environments. However, the direct emission of particle-phase biogenic sulfur from the ocean remains largely unexplored. Here we present measurements of ocean-derived particles containing reduced sulfur, detected as elemental sulfur ions (e.g., (32)S(+), (64)S2(+)), in seven different marine environments using real-time, single particle mass spectrometry; these particles have not been detected outside of the marine environment. These reduced sulfur compounds were associated with primary marine particle types and wind speeds typically between 5 and 10 m/s suggesting that these particles themselves are a primary emission. In studies with measurements of seawater properties, chlorophyll-a and atmospheric DMS concentrations were typically elevated in these same locations suggesting a biogenic source for these sulfur-containing particles. Interestingly, these sulfur-containing particles only appeared at night, likely due to rapid photochemical destruction during the daytime, and comprised up to ∼67% of the aerosol number fraction, particularly in the supermicrometer size range. These sulfur-containing particles were detected along the California coast, across the Pacific Ocean, and in the southern Indian Ocean suggesting that these particles represent a globally significant biogenic contribution to the marine aerosol burden.

  14. Impacts of the Mesoscale Ocean-Atmosphere Coupling on the Peru-Chile Ocean Dynamics: The Current-Induced Wind Stress Modulation

    Science.gov (United States)

    Oerder, V.; Colas, F.; Echevin, V.; Masson, S.; Lemarié, F.

    2018-02-01

    The ocean dynamical responses to the surface current-wind stress interaction at the oceanic mesoscale are investigated in the South-East Pacific using a high-resolution regional ocean-atmosphere coupled model. Two simulations are compared: one includes the surface current in the wind stress computation while the other does not. In the coastal region, absolute wind velocities are different between the two simulations but the wind stress remains very similar. As a consequence, the mean regional oceanic circulation is almost unchanged. On the contrary, the mesoscale activity is strongly reduced when taking into account the effect of the surface current on the wind stress. This is caused by a weakening of the eddy kinetic energy generation near the coast by the wind work and to intensified offshore eddy damping. We show that, above coherent eddies, the current-stress interaction generates eddy damping through Ekman pumping and eddy kinetic energy dissipation through wind work. This alters significantly the coherent eddy vertical structures compared with the control simulation, weakening the temperature and vorticity anomalies and increasing strongly the vertical velocity anomalies associated to eddies.

  15. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from METEOR, FRANKLIN and other platforms in the North Atlantic Ocean and World-Wide Distribution from 1967-01-11 to 1991-04-22 (NODC Accession 9500038)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 14 sets of Conductivity, Temperature and Depth (CTD) data were collected in from various parts of the World in North Atlantic Ocean as part of World Ocean...

  16. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from UNKNOWN PLATFORMS OF AUSTRALIA in the South Atlantic Ocean from 1972-02-01 to 1977-11-15 (NCEI Accession 9000036)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains ocean station and current data collected by Water & Sewerage Board in South Atlantic Ocean and submitted by Mr.K.H.J. Robin. The physical...

  17. Distinct mechanisms are responsible for osteopenia and growth retardation in OASIS-deficient mice.

    Science.gov (United States)

    Murakami, Tomohiko; Hino, Shin-Ichiro; Nishimura, Riko; Yoneda, Toshiyuki; Wanaka, Akio; Imaizumi, Kazunori

    2011-03-01

    Old astrocyte specifically induced substance (OASIS), which is a new type of endoplasmic reticulum (ER) stress transducer, is a basic leucine zipper transcription factor of the CREB/ATF family that contains a transmembrane domain and is processed by regulated intramembrane proteolysis in response to ER stress. OASIS is selectively expressed in certain types of cells such as astrocytes and osteoblasts. We have previously demonstrated that OASIS activates transcription of the type I collagen gene Col1a1 and contributes to the secretion of bone matrix proteins in osteoblasts, and that OASIS-/- mice exhibit osteopenia and growth retardation. In the present study, we examined whether osteopenia in OASIS-/- mice is rescued by OASIS introduction into osteoblasts. We generated OASIS-/- mice that specifically expressed OASIS in osteoblasts using a 2.3-kb osteoblast-specific type I collagen promoter (OASIS-/-;Tg mice). Histological analysis of OASIS-/-;Tg mice revealed that osteopenia in OASIS-/- mice was rescued by osteoblast-specific expression of the OASIS transgene. The decreased expression levels of type I collagen mRNAs in the bone tissues of OASIS-/- mice were recovered by the OASIS transgene accompanied by the rescue of an abnormal expansion of the rough ER in OASIS-/- osteoblasts. In contrast, growth retardation in OASIS-/- mice did not improve in OASIS-/-;Tg mice. Interestingly, the serum levels of growth hormone (GH) and insulin-like growth factor (IGF)-1 were downregulated in OASIS-/- mice compared with those in wild-type mice. These decreased GH and IGF-1 levels in OASIS-/- mice did not change when OASIS was introduced into osteoblasts. Taken together, these results indicate that OASIS regulates skeletal development by osteoblast-dependent and -independent mechanisms. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. The size distribution of marine atmospheric aerosol with regard to primary biological aerosol particles over the South Atlantic Ocean

    Science.gov (United States)

    Matthias-Maser, Sabine; Brinkmann, Jutta; Schneider, Wilhelm

    The marine atmosphere is characterized by particles which originate from the ocean and by those which reached the air by advection from the continent. The bubble-burst mechanism produces both sea salt as well as biological particles. The following article describes the determination of the size distribution of marine aerosol particles with special emphasis on the biological particles. Th data were obtained on three cruises with the German Research Vessel "METEOR" crossing the South Atlantic Ocean. The measurements showed that biological particles amount to 17% in number and 10% in volume concentration. Another type of particle became obvious in the marine atmosphere, the biologically contaminated particle, i.e. particles which consist partly (approximately up to one-third) of biological matter. Their concentration in the evaluated size class ( r>2 μm) is higher than the concentration of the pure biological particles. The concentrations vary over about one to two orders of magnitude during all cruises.

  19. Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: a multi model linear feedback analysis

    International Nuclear Information System (INIS)

    Roy, Tilla; Bopp, Laurent; Gehlen, Marion; Cadule, Patricia; Schneider, Birgit; Frolicher, Thomas L.; Segschneider, Joachim; Tjiputra, Jerry; Heinze, Christoph; Joos, Fortunat

    2011-01-01

    The increase in atmospheric CO 2 over this century depends on the evolution of the oceanic air-sea CO 2 uptake, which will be driven by the combined response to rising atmospheric CO 2 itself and climate change. Here, the future oceanic CO 2 uptake is simulated using an ensemble of coupled climate-carbon cycle models. The models are driven by CO 2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high-emission scenario. A linear feedback analysis successfully separates the regional future (2010-2100) oceanic CO 2 uptake into a CO 2 -induced component, due to rising atmospheric CO 2 concentrations, and a climate-induced component, due to global warming. The models capture the observation based magnitude and distribution of anthropogenic CO 2 uptake. The distributions of the climate-induced component are broadly consistent between the models, with reduced CO 2 uptake in the sub polar Southern Ocean and the equatorial regions, owing to decreased CO 2 solubility; and reduced CO 2 uptake in the mid-latitudes, owing to decreased CO 2 solubility and increased vertical stratification. The magnitude of the climate-induced component is sensitive to local warming in the southern extra-tropics, to large freshwater fluxes in the extra-tropical North Atlantic Ocean, and to small changes in the CO 2 solubility in the equatorial regions. In key anthropogenic CO 2 uptake regions, the climate-induced component offsets the CO 2 - induced component at a constant proportion up until the end of this century. This amounts to approximately 50% in the northern extra-tropics and 25% in the southern extra-tropics and equatorial regions. Consequently, the detection of climate change impacts on anthropogenic CO 2 uptake may be difficult without monitoring additional tracers, such as oxygen. (authors)

  20. Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: a multi model linear feedback analysis

    International Nuclear Information System (INIS)

    Roy, Tilla; Bopp, Laurent; Gehlen, Marion; Cadule, Patricia

    2011-01-01

    The increase in atmospheric CO 2 over this century depends on the evolution of the oceanic air-sea CO 2 uptake, which will be driven by the combined response to rising atmospheric CO 2 itself and climate change. Here, the future oceanic CO 2 uptake is simulated using an ensemble of coupled climate-carbon cycle models. The models are driven by CO 2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high-emission scenario. A linear feedback analysis successfully separates the regional future (2010-2100) oceanic CO 2 uptake into a CO 2 -induced component, due to rising atmospheric CO 2 concentrations, and a climate-induced component, due to global warming. The models capture the observation based magnitude and distribution of anthropogenic CO 2 uptake. The distributions of the climate-induced component are broadly consistent between the models, with reduced CO 2 uptake in the sub-polar Southern Ocean and the equatorial regions, owing to decreased CO 2 solubility; and reduced CO 2 uptake in the mid latitudes, owing to decreased CO 2 solubility and increased vertical stratification. The magnitude of the climate-induced component is sensitive to local warming in the southern extra tropics, to large freshwater fluxes in the extra tropical North Atlantic Ocean, and to small changes in the CO 2 solubility in the equatorial regions. In key anthropogenic CO 2 uptake regions, the climate-induced component offsets the CO 2 - induced component at a constant proportion up until the end of this century. This amounts to approximately 50% in the northern extra tropics and 25% in the southern extra tropics and equatorial regions. Consequently, the detection of climate change impacts on anthropogenic CO 2 uptake may be difficult without monitoring additional tracers, such as oxygen. (authors)

  1. The monitoring of atmospheric mercury species in the Southern Indian Ocean at Amsterdam Island (38°S

    Directory of Open Access Journals (Sweden)

    Barret M.

    2013-04-01

    Full Text Available The role of oceans in the global cycle of mercury is still poorly characterized, mainly because of a lack a long-term data on atmospheric mercury concentrations in the remote Southern Ocean. In the frame of GMOS (Global Mercury Observation System, we present here the first results from a new monitoring station at Amsterdam Island in the Southern Indian Ocean. For the period January to April 2012, we recorded mean concentration of gaseous elemental mercury (GEM, reactive gaseous mercury (RGM and particulate-bounded mercury (PHg of 1.03 ng m−3, 0.37 and 0.34 pg m−3 respectively. While GEM concentrations showed little variations, RGM and PHg exhibited fast variations with alternation of value below the instrumental detection limit and maximum values up to 4 pg m−3.

  2. Detecting Historical Vegetation Changes in the Dunhuang Oasis Protected Area Using Landsat Images

    Directory of Open Access Journals (Sweden)

    Xiuxia Zhang

    2017-09-01

    Full Text Available Abstract: Given its proximity to an artificial oasis, the Donghu Nature Reserve in the Dunhuang Oasis has faced environmental pressure and vegetation disturbances in recent decades. Satellite vegetation indices (VIs can be used to detect such changes in vegetation if the satellite images are calibrated to surface reflectance (SR values. The aim of this study was to select a suitable VI based on the Landsat Climate Data Record (CDR products and the absolute radiation-corrected results of Landsat L1T images to detect the spatio-temporal changes in vegetation for the Donghu Reserve during 1986–2015. The results showed that the VI difference (ΔVI images effectively reduced the changes in the source images. Compared with the other VIs, the soil-adjusted vegetation index (SAVI displayed greater robustness to atmospheric effects in the two types of SR images and was more responsive to vegetation changes caused by human factors. From 1986 to 2015, the positive changes in vegetation dominated the overall change trend, with changes in vegetation in the reserve decreasing during 1990–1995, increasing until 2005–2010, and then decreasing again. The vegetation changes were mainly distributed at the edge of the artificial oasis outside the reserve. The detected changes in vegetation in the reserve highlight the increased human pressure on the reserve.

  3. On the division of contribution of the atmosphere and ocean in the radiation of the earth for the tasks of remote sensing and climate

    Science.gov (United States)

    Sushkevich, T. A.; Strelkov, S. A.; Maksakova, S. V.

    2017-11-01

    We are talking about the national achievements of the world level in theory of radiation transfer in the system atmosphere-oceans and about the modern scientific potential developing in Russia, which adequately provides a methodological basis for theoretical and computational studies of radiation processes and radiation fields in the natural environments with the use of supercomputers and massively parallel processing for problems of remote sensing and the climate of Earth. A model of the radiation field in system "clouds cover the atmosphere-ocean" to the separation of the contributions of clouds, atmosphere and ocean.

  4. Modeling long-term carbon residue in the ocean-atmosphere system following large CO2 emissions

    Science.gov (United States)

    Towles, N. J.; Olson, P.; Gnanadesikan, A.

    2013-12-01

    We use the LOSCAR carbon cycle model (Zeebe et al., 2009; Zeebe, 2012) to calculate the residual carbon in the ocean and atmosphere following large CO2 emissions. We consider the system response to CO2 emissions ranging from 100 to 20000 PgC, and emission durations from 100 yr to 100 kyr, subject to a wide range of system parameters such as the strengths of silicate weathering and the oceanic biological carbon pump. We define the carbon gain factor as the ratio of residual carbon in the ocean-atmosphere to the total emitted carbon. For moderate sized emissions shorter than about 50 kyr, we find that the carbon gain factor grows during the emission and peaks at about 1.7, primarily due to the erosion of carbonate marine sediments. In contrast, for longer emissions, the carbon gain factor peaks at a smaller value, and for very large emissions (more than 5000 PgC), the gain factor decreases with emission size due to carbonate sediment exhaustion. This gain factor is sensitive to model parameters such as low latitude efficiency of the biological pump. The timescale for removal of the residual carbon (reducing the carbon gain factor to zero) depends strongly on the assumed sensitivity of silicate weathering to atmospheric pCO2, and ranges from less than one million years to several million years.

  5. Atmosphere surface storm track response to resolved ocean mesoscale in two sets of global climate model experiments

    Science.gov (United States)

    Small, R. Justin; Msadek, Rym; Kwon, Young-Oh; Booth, James F.; Zarzycki, Colin

    2018-05-01

    It has been hypothesized that the ocean mesoscale (particularly ocean fronts) can affect the strength and location of the overlying extratropical atmospheric storm track. In this paper, we examine whether resolving ocean fronts in global climate models indeed leads to significant improvement in the simulated storm track, defined using low level meridional wind. Two main sets of experiments are used: (i) global climate model Community Earth System Model version 1 with non-eddy-resolving standard resolution or with ocean eddy-resolving resolution, and (ii) the same but with the GFDL Climate Model version 2. In case (i), it is found that higher ocean resolution leads to a reduction of a very warm sea surface temperature (SST) bias at the east coasts of the U.S. and Japan seen in standard resolution models. This in turn leads to a reduction of storm track strength near the coastlines, by up to 20%, and a better location of the storm track maxima, over the western boundary currents as observed. In case (ii), the change in absolute SST bias in these regions is less notable, and there are modest (10% or less) increases in surface storm track, and smaller changes in the free troposphere. In contrast, in the southern Indian Ocean, case (ii) shows most sensitivity to ocean resolution, and this coincides with a larger change in mean SST as ocean resolution is changed. Where the ocean resolution does make a difference, it consistently brings the storm track closer in appearance to that seen in ERA-Interim Reanalysis data. Overall, for the range of ocean model resolutions used here (1° versus 0.1°) we find that the differences in SST gradient have a small effect on the storm track strength whilst changes in absolute SST between experiments can have a larger effect. The latter affects the land-sea contrast, air-sea stability, surface latent heat flux, and the boundary layer baroclinicity in such a way as to reduce storm track activity adjacent to the western boundary in the N

  6. Forcing of global ocean models using an atmospheric boundary layer model: assessing consequences for the simulation of the AMOC

    Science.gov (United States)

    Abel, Rafael; Boening, Claus

    2015-04-01

    Current practice in the atmospheric forcing of ocean model simulations can lead to unphysical behaviours. The problem lies in the bulk formulation of the turbulent air-sea fluxes in conjunction with a prescribed, and unresponsive, atmospheric state as given, e.g., by reanalysis products. This forcing formulation corresponds to assuming an atmosphere with infinite heat capacity, and effectively damps SST anomalies even on basin scales. It thus curtails an important negative feedback between meridional ocean heat transport and SST in the North Atlantic, rendering simulations of the AMOC in such models excessively sensitive to details in the freshwater fluxes. As a consequence, such simulations are known for spurious drift behaviors which can only partially controlled by introducing some (and sometimes strong) unphysical restoring of sea surface salinity. There have been several suggestions during the last 20 years for at least partially alleviating the problem by including some simplified model of the atmospheric boundary layer (AML) which allows a feedback of SST anomalies on the near-surface air temperature and humidity needed to calculate the surface fluxes. We here present simulations with a simple, only thermally active AML formulation (based on the 'CheapAML' proposed by Deremble et al., 2013) implemented in a global model configuration based on NEMO (ORCA05). In a suite of experiments building on the CORE-bulk forcing methodology, we examine some general features of the AML-solutions (in which only the winds are prescribed) in comparison to solutions with a prescribed atmosperic state. The focus is on the North Atlantic, where we find that the adaptation of the atmospheric temperature the simulated ocean state can lead to strong local modifications in the surface heat fluxes in frontal regions (e.g., the 'Northwest Corner'). We particularly assess the potential of the AML-forcing concept for obtaining AMOC-simulations with reduced spurious drift, without

  7. Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences

    Directory of Open Access Journals (Sweden)

    H. Angot

    2016-07-01

    Full Text Available Under the framework of the Global Mercury Observation System (GMOS project, a 3.5-year record of atmospheric gaseous elemental mercury (Hg(0 has been gathered at Dumont d'Urville (DDU, 66°40′ S, 140°01′ E, 43 m above sea level on the East Antarctic coast. Additionally, surface snow samples were collected in February 2009 during a traverse between Concordia Station located on the East Antarctic plateau and DDU. The record of atmospheric Hg(0 at DDU reveals particularities that are not seen at other coastal sites: a gradual decrease of concentrations over the course of winter, and a daily maximum concentration around midday in summer. Additionally, total mercury concentrations in surface snow samples were particularly elevated near DDU (up to 194.4 ng L−1 as compared to measurements at other coastal Antarctic sites. These differences can be explained by the more frequent arrival of inland air masses at DDU than at other coastal sites. This confirms the influence of processes observed on the Antarctic plateau on the cycle of atmospheric mercury at a continental scale, especially in areas subject to recurrent katabatic winds. DDU is also influenced by oceanic air masses and our data suggest that the ocean plays a dual role on Hg(0 concentrations. The open ocean may represent a source of atmospheric Hg(0 in summer whereas the sea-ice surface may provide reactive halogens in spring that can oxidize Hg(0. This paper also discusses implications for coastal Antarctic ecosystems and for the cycle of atmospheric mercury in high southern latitudes.

  8. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from OSHORO MARU in the Bay of Bengal, North Pacific Ocean and North Atlantic Ocean from 1987-11-27 to 1988-09-04 (NODC Accession 9700003)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hydrochemical, hydrophysical, and other data were collected from the OSHORO MARU from November 27, 1987 to September 4, 1988. Data were submitted by Katsuji...

  9. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from THOMAS G. THOMPSON in the TOGA Area - Pacific, North Pacific Ocean and South Pacific Ocean from 1992-03-19 to 1992-09-24 (NODC Accession 9700039)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hydrochemical, hydrophysical, and other data were collected from the THOMAS G. THOMPSON from March 19, 1992 to September 24, 1992. Data were submitted by Dr. Curt...

  10. A Study of Oceans and Atmospheric Interactions Associated with Tropical Cyclone Activity using Earth Observing Technology

    Science.gov (United States)

    Abdullah, Warith; Reddy, Remata

    From October 22nd to 30th, 2012 Hurricane Sandy was a huge storm of many abnormalities causing an estimated 50 billion dollars in damage. Tropical storm development states systems’ energy as product of warm sea surface temperatures (SST’s) and tropical cyclone heat potential (TCHP). Advances in Earth Observing (EO) technology, remote sensing and proxy remote sensing have allowed for accurate measurements of SST and TCHP information. In this study, we investigated rapid intensification of Sandy through EO applications for precipitable water vapor (PWAT), SST’s and TCHP during the period of October 27th. These data were obtained from NASA and NOAA satellites and NOAA National Buoy data center (NDBC). The Sensible Heat (Qs) fluxes were computed to determine available energy resulting from ocean-atmosphere interface. Buoy 41010, 120 NM east of Cape Canaveral at 0850 UTC measured 22.3 °C atmospheric temperatures and 27 °C SST, an interface of 4.7 °C. Sensible heat equation computed fluxes of 43.7 W/m2 at 982.0 mb central pressure. Sandy formed as late-season storm and near-surface air temperatures averaged > 21 °C according to NOAA/ESRL NCEP/NCAR reanalysis at 1000 mb and GOES 13 (EAST) geostationary water vapor imagery shows approaching cold front during October 27th. Sandy encountered massive dry air intrusion to S, SE and E quadrants of storm while travelling up U.S east coast but experienced no weakening. Cool, dry air intrusion was considered for PWAT investigation from closest sounding station during Oct. 27th 0900 - 2100 UTC at Charleston, SC station 72208. Measured PWAT totaled 42.97 mm, indicating large energy potential supply to the storm. The Gulf Stream was observed using NASA Short-term Prediction Research and Transition Center (SPoRT) MODIS SST analysis. The results show 5 °C warmer above average than surrounding cooler water, with > 25 °C water extent approximately 400 NM east of Chesapeake Bay and eddies > 26 °C. Results from sensible heat

  11. Flexible global ocean-atmosphere-land system model. A modeling tool for the climate change research community

    International Nuclear Information System (INIS)

    Zhou, Tianjun; Yu, Yongqiang; Liu, Yimin; Wang, Bin

    2014-01-01

    First book available on systematic evaluations of the performance of the global climate model FGOALS. Covers the whole field, ranging from the development to the applications of this climate system model. Provide an outlook for the future development of the FGOALS model system. Offers brief introduction about how to run FGOALS. Coupled climate system models are of central importance for climate studies. A new model known as FGOALS (the Flexible Global Ocean-Atmosphere-Land System model), has been developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (LASG/IAP, CAS), a first-tier national geophysical laboratory. It serves as a powerful tool, both for deepening our understanding of fundamental mechanisms of the climate system and for making decadal prediction and scenario projections of future climate change. ''Flexible Global Ocean-Atmosphere-Land System Model: A Modeling Tool for the Climate Change Research Community'' is the first book to offer systematic evaluations of this model's performance. It is comprehensive in scope, covering both developmental and application-oriented aspects of this climate system model. It also provides an outlook of future development of FGOALS and offers an overview of how to employ the model. It represents a valuable reference work for researchers and professionals working within the related areas of climate variability and change.

  12. AccuRT: A versatile tool for radiative transfer simulations in the coupled atmosphere-ocean system

    Science.gov (United States)

    Hamre, Børge; Stamnes, Snorre; Stamnes, Knut; Stamnes, Jakob

    2017-02-01

    Reliable, accurate, and efficient modeling of the transport of electromagnetic radiation in turbid media has important applications in the study of the Earth's climate by remote sensing. For example, such modeling is needed to develop forward-inverse methods used to quantify types and concentrations of aerosol and cloud particles in the atmosphere, the dissolved organic and particulate biogeochemical matter in lakes, rivers, coastal, and open-ocean waters. It is also needed to simulate the performance of remote sensing detectors deployed on aircraft, balloons, and satellites as well as radiometric detectors deployed on buoys, gliders and other aquatic observing systems. Accurate radiative transfer modeling is also required to compute irradiances and scalar irradiances that are used to compute warming/cooling and photolysis rates in the atmosphere and primary production and warming/cooling rates in the water column. AccuRT is a radiative transfer model for the coupled atmosphere-water system that is designed to be a versatile tool for researchers in the ocean optics and remote sensing communities. It addresses the needs of researchers interested in analyzing irradiance and radiance measurements in the field and laboratory as well as those interested in making simulations of the top-of-the-atmosphere radiance in support of remote sensing algorithm development.

  13. Flexible global ocean-atmosphere-land system model. A modeling tool for the climate change research community

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Tianjun; Yu, Yongqiang; Liu, Yimin; Wang, Bin (eds.) [Chinese Academy of Sciences, Beijing, (China). Inst. of Atmospheric Physics

    2014-04-01

    First book available on systematic evaluations of the performance of the global climate model FGOALS. Covers the whole field, ranging from the development to the applications of this climate system model. Provide an outlook for the future development of the FGOALS model system. Offers brief introduction about how to run FGOALS. Coupled climate system models are of central importance for climate studies. A new model known as FGOALS (the Flexible Global Ocean-Atmosphere-Land System model), has been developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences (LASG/IAP, CAS), a first-tier national geophysical laboratory. It serves as a powerful tool, both for deepening our understanding of fundamental mechanisms of the climate system and for making decadal prediction and scenario projections of future climate change. ''Flexible Global Ocean-Atmosphere-Land System Model: A Modeling Tool for the Climate Change Research Community'' is the first book to offer systematic evaluations of this model's performance. It is comprehensive in scope, covering both developmental and application-oriented aspects of this climate system model. It also provides an outlook of future development of FGOALS and offers an overview of how to employ the model. It represents a valuable reference work for researchers and professionals working within the related areas of climate variability and change.

  14. Overview Kepuasan Pelanggan: Studi Kasus Pelayanan Rijstaffel di Restoran Oasis

    Directory of Open Access Journals (Sweden)

    Maria Pia Adiati

    2016-08-01

    Full Text Available Rijstaffel service is not common found in fine dining restaurant in Indonesia. Oasis Restaurant in Jalan Raden Saleh, Jakarta, is a restaurant that is consistent in serving rijstaffel menu. The objective of this research is to analyze the level of consumer satisfaction and service quality in rijstaffel service at Oasis Restaurant. Research used qualitative method with library research by analyzing the questionnaire distributed by Oasis on Mei 2013 with 21 respondents. The result is the indicators which got excellence point were service, ambience, value for money, food; and the indicator which got good point was home band and vocal group.

  15. Coupled ocean-atmosphere surface variability and its climate impacts in the tropical Atlantic region

    Science.gov (United States)

    Fontaine, B.; Janicot, Serge; Roucou, P.

    This study examines time evolution and statistical relationships involving the two leading ocean-atmosphere coupled modes of variability in the tropical Atlantic and some climate anomalies over the tropical 120°W-60°W region using selected historical files (75-y near global SSTs and precipitation over land), more recent observed data (30-y SST and pseudo wind stress in the tropical Atlantic) and reanalyses from the US National Centers for Environmental Prediction (NCEP/NCAR) reanalysis System on the period 1968-1997: surface air temperature, sea level pressure, moist static energy content at 850 hPa, precipitable water and precipitation. The first coupled mode detected through singular value decomposition of the SST and pseudo wind-stress data over the tropical Atlantic (30°N-20°S) expresses a modulation in the thermal transequatorial gradient of SST anomalies conducted by one month leading wind-stress anomalies mainly in the tropical north Atlantic during northern winter and fall. It features a slight dipole structure in the meridional plane. Its time variability is dominated by a quasi-decadal signal well observed in the last 20-30 ys and, when projected over longer-term SST data, in the 1920s and 1930s but with shorter periods. The second coupled mode is more confined to the south-equatorial tropical Atlantic in the northern summer and explains considerably less wind-stress/SST cross-covariance. Its time series features an interannual variability dominated by shorter frequencies with increased variance in the 1960s and 1970s before 1977. Correlations between these modes and the ENSO-like Nino3 index lead to decreasing amplitude of thermal anomalies in the tropical Atlantic during warm episodes in the Pacific. This could explain the nonstationarity of meridional anomaly gradients on seasonal and interannual time scales. Overall the relationships between the oceanic component of the coupled modes and the climate anomaly patterns denote thermodynamical

  16. North Atlantic atmospheric and ocean inter-annual variability over the past fifty years - Dominant patterns and decadal shifts

    Science.gov (United States)

    Hauser, Tristan; Demirov, Entcho; Zhu, Jieshun; Yashayaev, Igor

    2015-03-01

    The atmosphere and ocean of the North Atlantic have undergone significant changes in the past century. To understand these changes, their mechanisms, and their regional implications requires a quantitative understanding of processes in the coupled ocean and atmosphere system. Central to this understanding is the role played by the dominant patterns of ocean and atmospheric variability which define coherent variations in physical characteristics over large areas. Cluster analysis is used in this article to identify the patterns of the North Atlantic atmospheric variability in the subseasonal and interannual spectral intervals. Four dominant subseasonal weather regimes are defined using Bayesian Gaussian mixture models. All correlation patterns of the Sea Level Pressure (SLP) anomalies with the membership probability time series for the weather regimes show similarities with the dipole structure typical for the North Atlantic Oscillation (NAO). The SLP patterns of two of the regimes represent the opposite phases NAO+ and NAO-. The two other weather regimes, the Atlantic Ridge (AR) and Scandinavian-Greenland dipole (SG), have dipole spatial structures with the northern and southern centers of action shifted with respect to the NAO pattern. These two patterns define blocking structures over Scandinavia and near the southern tip of Greenland, respectively. The storm tracks typical for the four regimes resemble the well known paths for positive/negative phases of NAO for the NAO+/NAO- weather regimes, and paths influenced by blocking off the south Greenland tip for AR and over Scandinavia for SG. The correlation patterns of momentum and heat fluxes to the ocean for the four regimes have tripole structures with positive (warm) downward heat flux anomalies over the Subpolar North Atlantic (SPNA) for the NAO- and the AR and negative heat flux anomalies over the SPNA for the NAO+. The downward heat flux anomalies associated with the SG are negative over the Labrador Sea and

  17. Development and performance of a new version of the OASIS coupler, OASIS3-MCT_3.0

    Directory of Open Access Journals (Sweden)

    A. Craig

    2017-09-01

    Full Text Available OASIS is coupling software developed primarily for use in the climate community. It provides the ability to couple different models with low implementation and performance overhead. OASIS3-MCT is the latest version of OASIS. It includes several improvements compared to OASIS3, including elimination of a separate hub coupler process, parallelization of the coupling communication and run-time grid interpolation, and the ability to easily reuse mapping weight files. OASIS3-MCT_3.0 is the latest release and includes the ability to couple between components running sequentially on the same set of tasks as well as to couple within a single component between different grids or decompositions such as physics, dynamics, and I/O. OASIS3-MCT has been tested with different configurations on up to 32 000 processes, with components running on high-resolution grids with up to 1.5 million grid cells, and with over 10 000 2-D coupling fields. Several new features will be available in OASIS3-MCT_4.0, and some of those are also described.

  18. Development and performance of a new version of the OASIS coupler, OASIS3-MCT_3.0

    Science.gov (United States)

    Craig, Anthony; Valcke, Sophie; Coquart, Laure

    2017-09-01

    OASIS is coupling software developed primarily for use in the climate community. It provides the ability to couple different models with low implementation and performance overhead. OASIS3-MCT is the latest version of OASIS. It includes several improvements compared to OASIS3, including elimination of a separate hub coupler process, parallelization of the coupling communication and run-time grid interpolation, and the ability to easily reuse mapping weight files. OASIS3-MCT_3.0 is the latest release and includes the ability to couple between components running sequentially on the same set of tasks as well as to couple within a single component between different grids or decompositions such as physics, dynamics, and I/O. OASIS3-MCT has been tested with different configurations on up to 32 000 processes, with components running on high-resolution grids with up to 1.5 million grid cells, and with over 10 000 2-D coupling fields. Several new features will be available in OASIS3-MCT_4.0, and some of those are also described.

  19. Archive of Geosample Data and Information from the Oregon State University (OSU) College of Earth, Ocean and Atmospheric Sciences (CEOAS) Marine Geology Repository (MGR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Oregon State University Marine Geology Repository (OSU-MGR) is a partner in the Index to Marine and Lacustrine Geological Samples (IMLGS) database, contributing...

  20. Quality-Controlled Underway Oceanographic and Meteorological Data from the Center for Ocean-Atmospheric Predictions Center (COAPS) - Shipboard Automated Meteorological and Oceanographic System (SAMOS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Florida State University has been operating a data assembly center (DAC) to collect, quality evaluate, and distribute Shipboard Automated Meteorological and...

  1. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GYRE in the North Atlantic Ocean from 1977-02-10 to 1977-03-07 (NODC Accession 7800459)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf Study (OCS) Benchmark Study in the North Atlantic which ran from February 10 to March 7, 1977 from...

  2. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GILLISS in the North Atlantic Ocean from 1977-05-05 to 1977-09-02 (NODC Accession 7800461)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf Study (OCS) benchmark study in the North Atlantic which ran May 5 to September 2, 1977 from the R/V...

  3. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from KNORR in the North Atlantic Ocean from 1977-11-22 to 1977-12-04 (NODC Accession 7800462)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf Study (OCS) benchmark study in the North Atlantic which ran November to December 1977 from the R/V...

  4. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GYRE in the North Atlantic Ocean from 1977-05-05 to 1977-05-25 (NODC Accession 7800460)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf study (OCS) benchmark study in the North Atlantic which ran during the month of May 77 from the R/V...

  5. The crucial role of ocean-atmosphere coupling on the Indian monsoon anomalous response during dipole events

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, R.; Swapna, P.; Ayantika, D.C.; Mujumdar, M. [Indian Institute of Tropical Meteorology, Climate and Global Modelling Division, Pune (India); Sundaram, Suchithra [Indian Institute of Tropical Meteorology, Climate and Global Modelling Division, Pune (India); Universite Catholique de Louvain, Institut d' Astronomie de Geophysique G. Lemaitre, Louvain-La-Neuve (Belgium); Kumar, Vinay [Indian Institute of Tropical Meteorology, Climate and Global Modelling Division, Pune (India); Florida State University, Department of Meteorology, Tallahassee, FL (United States)

    2011-07-15

    This paper examines an issue concerning the simulation of anomalously wet Indian summer monsoons like 1994 which co-occurred with strong positive Indian Ocean Dipole (IOD) conditions in the tropical Indian Ocean. Contrary to observations it has been noticed that standalone atmospheric general circulation models (AGCM) forced with observed SST boundary condition, consistently depicted a decrease of the summer monsoon rainfall during 1994 over the Indian region. Given the ocean-atmosphere coupling during IOD events, we have examined whether the failure of standalone AGCM simulations in capturing wet Indian monsoons like 1994 can be remedied by including a simple form of coupling that allows the monsoon circulation to dynamically interact with the IOD anomalies. With this view, we have performed a suite of simulations by coupling an AGCM to a slab-ocean model with spatially varying mixed-layer-depth (MLD) specified from observations for the 1994 IOD; as well as four other cases (1983, 1997, 2006, 2007). The specification of spatially varying MLD from observations allows us to constrain the model to observed IOD conditions. It is seen that the inclusion of coupling significantly improves the large-scale circulation response by strengthening the monsoon cross-equatorial flow; leading to precipitation enhancement over the subcontinent and rainfall decrease over south-eastern tropical Indian Ocean - in a manner broadly consistent with observations. A plausible physical mechanism is suggested to explain the monsoonal response in the coupled frame-work. These results warrant the need for improved monsoon simulations with fully coupled models to be able to better capture the observed monsoon interannual variability. (orig.)

  6. Consistent past half-century trends in the atmosphere, the sea ice and the ocean at high southern latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Goosse, Hugues; Montety, Anne de; Crespin, Elisabeth [Universite Catholique de Louvain, Institut d' Astronomie et de Geophysique G. Lemaitre, Louvain-la-Neuve (Belgium); Lefebvre, Wouter [Universite Catholique de Louvain, Institut d' Astronomie et de Geophysique G. Lemaitre, Louvain-la-Neuve (Belgium); The Vlaams Instituut voor Technologisch Onderzoek (VITO), Mol (Belgium); Orsi, Alejandro H. [Texas A and M University, Department of Oceanography, College Station, TX (United States)

    2009-12-15

    Simulations performed with the climate model LOVECLIM, aided with a simple data assimilation technique that forces a close matching of simulated and observed surface temperature variations, are able to reasonably reproduce the observed changes in the lower atmosphere, sea ice and ocean during the second half of the twentieth century. Although the simulated ice area slightly increases over the period 1980-2000, in agreement with observations, it decreases by 0.5 x 10{sup 6} km{sup 2} between early 1960s and early 1980s. No direct and reliable sea ice observations are available to firmly confirm this simulated decrease, but it is consistent with the data used to constrain model evolution as well as with additional independent data in both the atmosphere and the ocean. The simulated reduction of the ice area between the early 1960s and early 1980s is similar to the one simulated over that period as a response to the increase in greenhouse gas concentrations in the atmosphere while the increase in ice area over the last decades of the twentieth century is likely due to changes in atmospheric circulation. However, the exact contribution of external forcing and internal variability in the recent changes cannot be precisely estimated from our results. Our simulations also reproduce the observed oceanic subsurface warming north of the continental shelf of the Ross Sea and the salinity decrease on the Ross Sea continental shelf. Parts of those changes are likely related to the response of the system to the external forcing. Modifications in the wind pattern, influencing the ice production/melting rates, also play a role in the simulated surface salinity decrease. (orig.)

  7. The Role of the Indian Ocean Sector for Prediction of the Coupled Indo-Pacific System: Impact of Atmospheric Coupling

    Science.gov (United States)

    Hackert, E. C.; Busalacchi, A. J.; Carton, J.; Murtugudde, R.; Arkin, P.; Evans, M. N.

    2017-01-01

    Indian Ocean (IO) dynamics impact ENSO predictability by influencing wind and precipitation anomalies in the Pacific. To test if the upstream influence of the IO improves ENSO validation statistics, a combination of forced ocean, atmosphere, and coupled models are utilized. In one experiment, the full tropical Indo-Pacific region atmosphere is forced by observed interannual SST anomalies. In the other, the IO is forced by climatological SST. Differences between these two forced atmospheric model experiments spotlight a much richer wind response pattern in the Pacific than previous studies that used idealized forcing and simple linear atmospheric models. Weak westerlies are found near the equator similar to earlier literature. However, at initialization strong easterlies between 30 deg. S to 10 deg. S and 0 deg. N to 25 deg. N and equatorial convergence of the meridional winds across the entire Pacific are unique findings from this paper. The large-scale equatorial divergence west of the dateline and northeasterly-to-northwesterly cross-equatorial flow converging on the equator east of the dateline in the Pacific are generated from interannual IO SST coupling. In addition, off-equatorial downwelling curl impacts large-scale oceanic waves (i.e., Rossby waves reflect as western boundary Kelvin waves). After 3 months, these downwelling equatorial Kelvin waves propagate across the Pacific and strengthen the NINO3 SST. Eventually Bjerknes feedbacks take hold in the eastern Pacific which allows this warm anomaly to grow. Coupled forecasts for NINO3 SST anomalies for 1993-2014 demonstrate that including interannual IO forcing significantly improves predictions for 3-9 month lead times.

  8. The role of the Indian Ocean sector for prediction of the coupled Indo-Pacific system: Impact of atmospheric coupling

    Science.gov (United States)

    Hackert, E. C.; Busalacchi, A. J.; Carton, J.; Murtugudde, R.; Arkin, P.; Evans, M. N.

    2017-04-01

    Indian Ocean (IO) dynamics impact ENSO predictability by influencing wind and precipitation anomalies in the Pacific. To test if the upstream influence of the IO improves ENSO validation statistics, a combination of forced ocean, atmosphere, and coupled models are utilized. In one experiment, the full tropical Indo-Pacific region atmosphere is forced by observed interannual SST anomalies. In the other, the IO is forced by climatological SST. Differences between these two forced atmospheric model experiments spotlight a much richer wind response pattern in the Pacific than previous studies that used idealized forcing and simple linear atmospheric models. Weak westerlies are found near the equator similar to earlier literature. However, at initialization strong easterlies between 30°S-10°S and 0°N-25°N and equatorial convergence of the meridional winds across the entire Pacific are unique findings from this paper. The large-scale equatorial divergence west of the dateline and northeasterly-to-northwesterly cross-equatorial flow converging on the equator east of the dateline in the Pacific are generated from interannual IO SST coupling. In addition, off-equatorial downwelling curl impacts large-scale oceanic waves (i.e., Rossby waves reflect as western boundary Kelvin waves). After 3 months, these downwelling equatorial Kelvin waves propagate across the Pacific and strengthen the NINO3 SST. Eventually Bjerknes feedbacks take hold in the eastern Pacific which allows this warm anomaly to grow. Coupled forecasts for NINO3 SST anomalies for 1993-2014 demonstrate that including interannual IO forcing significantly improves predictions for 3-9 month lead times.

  9. Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO/sub 2/ during the past decades

    Energy Technology Data Exchange (ETDEWEB)

    Revelle, R; Suess, H E

    1957-01-01

    From a comparison of C/sup 14//C/sup 12/ and C/sup 13//C/sup 12/ ratios in wood and in marine material and from a slight decrease of the C/sup 14/ concentration in terrestrial plants over the past 50 years it can be concluded that the average lifetime of a CO/sub 2/ molecule in the atmosphere before it is dissolved into the sea is of the order of 10 years. This means that most of the CO/sub 2/ released by artificial fuel combustion since the beginning of the industrial revolution must have been absorbed by the oceans. The increase of atmospheric CO/sub 2/ from this cause is at present small but may become significant during future decades of industrial fuel combustion continues to rise exponentially. Present data on the total amount of CO/sub 2/ in the atmosphere, on the rates and mechanisms of exchange, and on possible fluctuations in terrestrial and marine organic carbon, are inadequate for accurate measurement of future changes in atmospheric CO/sub 2/. An opportunity exists during the international geophysical year to obtain much of the necessary information.

  10. Computer simulations of large asteroid impacts into oceanic and continental sites--preliminary results on atmospheric, cratering and ejecta dynamics

    Science.gov (United States)

    Roddy, D.J.; Schuster, S.H.; Rosenblatt, M.; Grant, L.B.; Hassig, P.J.; Kreyenhagen, K.N.

    1987-01-01

    Computer simulations have been completed that describe passage of a 10-km-diameter asteroid through the Earth's atmosphere and the subsequent cratering and ejecta dynamics caused by impact of the asteroid into both oceanic and continental sites. The asteroid was modeled as a spherical body moving vertically at 20 km/s with a kinetic energy of 2.6 ?? 1030 ergs (6.2 ?? 107 Mt ). Detailed material modeling of the asteroid, ocean, crustal units, sedimentary unit, and mantle included effects of strength and fracturing, generic asteroid and rock properties, porosity, saturation, lithostatic stresses, and geothermal contributions, each selected to simulate impact and geologic conditions that were as realistic as possible. Calculation of the passage of the asteroid through a U.S. Standard Atmosphere showed development of a strong bow shock wave followed by a highly shock compressed and heated air mass. Rapid expansion of this shocked air created a large low-density region that also expanded away from the impact area. Shock temperatures in air reached ???20,000 K near the surface of the uplifting crater rim and were as high as ???2000 K at more than 30 km range and 10 km altitude. Calculations to 30 s showed that the shock fronts in the air and in most of the expanding shocked air mass preceded the formation of the crater, ejecta, and rim uplift and did not interact with them. As cratering developed, uplifted rim and target material were ejected into the very low density, shock-heated air immediately above the forming crater, and complex interactions could be expected. Calculations of the impact events showed equally dramatic effects on the oceanic and continental targets through an interval of 120 s. Despite geologic differences in the targets, both cratering events developed comparable dynamic flow fields and by ???29 s had formed similar-sized transient craters ???39 km deep and ???62 km across. Transient-rim uplift of ocean and crust reached a maximum altitude of nearly

  11. Evaluation of a present-day climate simulation with a new coupled atmosphere-ocean model GENMOM

    Directory of Open Access Journals (Sweden)

    J. R. Alder

    2011-02-01

    Full Text Available We present a new, non-flux corrected AOGCM, GENMOM, that combines the GENESIS version 3 atmospheric GCM (Global Environmental and Ecological Simulation of Interactive Systems and MOM2 (Modular Ocean Model version 2 nominally at T31 resolution. We evaluate GENMOM by comparison with reanalysis products (e.g., NCEP2 and three models used in the IPCC AR4 assessment. GENMOM produces a global temperature bias of 0.6 °C. Atmospheric features such as the jet stream structure and major semi-permanent sea level pressure centers are well simulated as is the mean planetary-scale wind structure that is needed to produce the correct position of stormtracks. Most ocean surface currents are reproduced except where they are not resolvable at T31 resolution. Overall, GENMOM captures reasonably well the observed gradients and spatial distributions of annual surface temperature and precipitation and the simulations are on par with other AOGCMs. Deficiencies in the GENMOM simulations include a warm bias in the surface temperature over the southern oceans, a split in the ITCZ and weaker-than-observed overturning circulation.

  12. The Ocean Colour Climate Change Initiative: I. A Methodology for Assessing Atmospheric Correction Processors Based on In-Situ Measurements

    Science.gov (United States)

    Muller, Dagmar; Krasemann, Hajo; Brewin, Robert J. W.; Deschamps, Pierre-Yves; Doerffer, Roland; Fomferra, Norman; Franz, Bryan A.; Grant, Mike G.; Groom, Steve B.; Melin, Frederic; hide

    2015-01-01

    The Ocean Colour Climate Change Initiative intends to provide a long-term time series of ocean colour data and investigate the detectable climate impact. A reliable and stable atmospheric correction procedure is the basis for ocean colour products of the necessary high quality. In order to guarantee an objective selection from a set of four atmospheric correction processors, the common validation strategy of comparisons between in-situ and satellite derived water leaving reflectance spectra, is extended by a ranking system. In principle, the statistical parameters such as root mean square error, bias, etc. and measures of goodness of fit, are transformed into relative scores, which evaluate the relationship of quality dependent on the algorithms under study. The sensitivity of these scores to the selected database has been assessed by a bootstrapping exercise, which allows identification of the uncertainty in the scoring results. Although the presented methodology is intended to be used in an algorithm selection process, this paper focusses on the scope of the methodology rather than the properties of the individual processors.

  13. Metrological challenges for measurements of key climatological observables: oceanic salinity and pH, and atmospheric humidity. Part 1: overview

    Science.gov (United States)

    Feistel, R.; Wielgosz, R.; Bell, S. A.; Camões, M. F.; Cooper, J. R.; Dexter, P.; Dickson, A. G.; Fisicaro, P.; Harvey, A. H.; Heinonen, M.; Hellmuth, O.; Kretzschmar, H.-J.; Lovell-Smith, J. W.; McDougall, T. J.; Pawlowicz, R.; Ridout, P.; Seitz, S.; Spitzer, P.; Stoica, D.; Wolf, H.

    2016-02-01

    Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest ‘greenhouse’ gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organizations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology.

  14. OASIS: An automotive analysis and safety engineering instrument

    International Nuclear Information System (INIS)

    Mader, Roland; Armengaud, Eric; Grießnig, Gerhard; Kreiner, Christian; Steger, Christian; Weiß, Reinhold

    2013-01-01

    In this paper, we describe a novel software tool named OASIS (AutOmotive Analysis and Safety EngIneering InStrument). OASIS supports automotive safety engineering with features allowing the creation of consistent and complete work products and to simplify and automate workflow steps from early analysis through system development to software development. More precisely, it provides support for (a) model creation and reuse, (b) analysis and documentation and (c) configuration and code generation. We present OASIS as a part of a tool chain supporting the application of a safety engineering workflow aligned with the automotive safety standard ISO 26262. In particular, we focus on OASIS' (1) support for property checking and model correction as well as its (2) support for fault tree generation and FMEA (Failure Modes and Effects Analysis) table generation. Finally, based on the case study of hybrid electric vehicle development, we demonstrate that (1) and (2) are able to strongly support FTA (Fault Tree Analysis) and FMEA

  15. Millennial-scale changes in atmospheric CO2 levels linked to the Southern Ocean carbon isotope gradient and dust flux

    Science.gov (United States)

    Ziegler, Martin; Diz, Paula; Hall, Ian R.; Zahn, Rainer

    2013-06-01

    The rise in atmospheric CO2 concentrations observed at the end of glacial periods has, at least in part, been attributed to the upwelling of carbon-rich deep water in the Southern Ocean. The magnitude of outgassing of dissolved CO2, however, is influenced by the biological fixation of upwelled inorganic carbon and its transfer back to the deep sea as organic carbon. The efficiency of this biological pump is controlled by the extent of nutrient utilization, which can be stimulated by the delivery of iron by atmospheric dust particles. Changes in nutrient utilization should be reflected in the δ13C gradient between intermediate and deep waters. Here we use the δ13C values of intermediate- and bottom-dwelling foraminifera to reconstruct the carbon isotope gradient between thermocline and abyssal water in the subantarctic zone of the South Atlantic Ocean over the past 360,000 years. We find millennial-scale oscillations of the carbon isotope gradient that correspond to changes in dust flux and atmospheric CO2 concentrations as reported from Antarctic ice cores. We interpret this correlation as a relationship between the efficiency of the biological pump and fertilization by dust-borne iron. As the correlation is exponential, we suggest that the sensitivity of the biological pump to dust-borne iron fertilization may be increased when the background dust flux is low.

  16. The Influence of Air-Sea Fluxes on Atmospheric Aerosols During the Summer Monsoon Over the Tropical Indian Ocean

    Science.gov (United States)

    Zavarsky, Alex; Booge, Dennis; Fiehn, Alina; Krüger, Kirstin; Atlas, Elliot; Marandino, Christa

    2018-01-01

    During the summer monsoon, the western tropical Indian Ocean is predicted to be a hot spot for dimethylsulfide emissions, the major marine sulfur source to the atmosphere, and an important aerosol precursor. Other aerosol relevant fluxes, such as isoprene and sea spray, should also be enhanced, due to the steady strong winds during the monsoon. Marine air masses dominate the area during the summer monsoon, excluding the influence of continentally derived pollutants. During the SO234-2/235 cruise in the western tropical Indian Ocean from July to August 2014, directly measured eddy covariance DMS fluxes confirm that the area is a large source of sulfur to the atmosphere (cruise average 9.1 μmol m-2 d-1). The directly measured fluxes, as well as computed isoprene and sea spray fluxes, were combined with FLEXPART backward and forward trajectories to track the emissions in space and time. The fluxes show a significant positive correlation with aerosol data from the Terra and Suomi-NPP satellites, indicating a local influence of marine emissions on atmospheric aerosol numbers.

  17. 76 FR 54217 - Membership of the National Oceanic and Atmospheric Administration Performance Review Board

    Science.gov (United States)

    2011-08-31

    ... Koch Director, Office of Education. Maureen E. Wylie Chief Financial Officer, Office of the Chief Financial Officer. Charles S. Baker Deputy Assistant Administrator, NESDIS National Environmental Satellite... Financial Officer National Ocean Service. David Robinson Associate Director for Management Resources...

  18. 76 FR 59662 - Membership of the National Oceanic and Atmospheric Administration Performance Review Board

    Science.gov (United States)

    2011-09-27

    ... Koch Director, Office of Education, Office of Education. Maureen E. Wylie Chief Financial Officer, Office of the Chief Financial Officer. Charles S. Baker Deputy Assistant Administrator, NESDIS, National.... Cartwright.... Chief Financial Officer, National Ocean Service. David Robinson Associate Director for...

  19. A bio-optical model suitable for use in forward and inverse coupled atmosphere-ocean radiative transfer models

    International Nuclear Information System (INIS)

    Zhang Kexin; Li Wei; Eide, Hans; Stamnes, Knut

    2007-01-01

    A simple, yet complete bio-optical model for the inherent optical properties (IOPs) of oceanic waters is developed. This bio-optical model is specifically designed for use in comprehensive, multiple scattering radiative transfer models for the coupled atmosphere-ocean system. Such models can be used to construct next-generation algorithms for simultaneous retrieval of aerosol and marine parameters. The computed remote sensing reflectance R rs (λ) is validated against field measurements of R rs (λ) compiled in the SeaBASS data base together with simultaneous chlorophyll concentrations (C) ranging from 0.03 to 100mgm -3 . This connection between R rs and C is used to construct a chlorophyll concentration retrieval algorithm that yields reliable results for a large range of chlorophyll concentrations. The overall performance of a MODIS/VIIRS chlorophyll concentration retrieval algorithm is found to be less satisfactory

  20. Oasis: online analysis of small RNA deep sequencing data.

    Science.gov (United States)

    Capece, Vincenzo; Garcia Vizcaino, Julio C; Vidal, Ramon; Rahman, Raza-Ur; Pena Centeno, Tonatiuh; Shomroni, Orr; Suberviola, Irantzu; Fischer, Andre; Bonn, Stefan

    2015-07-01

    Oasis is a web application that allows for the fast and flexible online analysis of small-RNA-seq (sRNA-seq) data. It was designed for the end user in the lab, providing an easy-to-use web frontend including video tutorials, demo data and best practice step-by-step guidelines on how to analyze sRNA-seq data. Oasis' exclusive selling points are a differential expression module that allows for the multivariate analysis of samples, a classification module for robust biomarker detection and an advanced programming interface that supports the batch submission of jobs. Both modules include the analysis of novel miRNAs, miRNA targets and functional analyses including GO and pathway enrichment. Oasis generates downloadable interactive web reports for easy visualization, exploration and analysis of data on a local system. Finally, Oasis' modular workflow enables for the rapid (re-) analysis of data. Oasis is implemented in Python, R, Java, PHP, C++ and JavaScript. It is freely available at http://oasis.dzne.de. stefan.bonn@dzne.de Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

  1. A numerical investigation of the atmosphere-ocean thermal contrast over the coastal upwelling region of Cabo Frio, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Dourado, M. [Departamento de Meteorologia, Universidade Federal de Pelotas, Pelotas RS (Brazil)]. E-mail: marcelo_dourado@ufpel.edu.br; Pereira de Oliveira, A. [Departamento de Ciencias Atmosfericas, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, (Brazil)

    2008-01-15

    An one-dimensional atmospheric second order closure model, coupled to an oceanic mixed layer model, is used to investigate the short term variation of the atmospheric and oceanic boundary layers in the coastal upwelling area of Cabo Frio, Brazil (23 degrees Celsius S, 42 degrees Celsius 08' W). The numerical simulations were carried out to evaluate the impact caused by the thermal contrast between atmosphere and ocean on the vertical extent and other properties of both atmospheric and oceanic boundary layers. The numerical simulations were designed taking as reference the observations carried out during the passage of a cold front that disrupted the upwelling regime in Cabo Frio in July of 1992. The simulations indicated that in 10 hours the mechanical mixing, sustained by a constant background flow of 10 m s-1, increases the atmospheric boundary layer in 214 m when the atmosphere is initially 2 K warmer than the ocean (positive thermal contrast observed during upwelling regime). For an atmosphere initially -2 K colder than the ocean (negative thermal contrast observed during passage of the cold front), the incipient thermal convection intensifies the mechanical mixing increasing the vertical extent of the atmospheric boundary layer in 360 m. The vertical evolution of the atmospheric boundary layer is consistent with the observations carried out in Cabo Frio during upwelling condition. When the upwelling is disrupted, the discrepancy between the simulated and observed atmospheric boundary layer heights in Cabo Frio during July of 1992 increases considerably. During the period of 10 hours, the simulated oceanic mixed layer deepens 2 m and 5.4 m for positive and negative thermal contrasts of 2 K and -2 K, respectively. In the latter case, the larger vertical extent of the oceanic mixed layer is due to the presence of thermal convection in the atmospheric boundary layer, which in turn is associated to the absence of upwelling caused by the passage of cold fronts

  2. Bi-decadal variability excited in the coupled ocean-atmosphere system by strong tropical volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Zanchettin, D.; Lorenz, S.; Lohmann, K.; Jungclaus, J.H. [Max Planck Institute for Meteorology, Ocean in the Earth System Department, Hamburg (Germany); Timmreck, C. [Max Planck Institute for Meteorology, Atmosphere in the Earth System Department, Hamburg (Germany); Graf, H.-F. [University of Cambridge, Centre for Atmospheric Science, Cambridge (United Kingdom); Rubino, A. [Ca' Foscari University, Department of Environmental Sciences, Venice (Italy); Krueger, K. [Leibniz-Institute of Marine Sciences, IFM-GEOMAR, Kiel (Germany)

    2012-07-15

    Decadal and bi-decadal climate responses to tropical strong volcanic eruptions (SVEs) are inspected in an ensemble simulation covering the last millennium based on the Max Planck Institute - Earth system model. An unprecedentedly large collection of pre-industrial SVEs (up to 45) producing a peak annual-average top-of-atmosphere radiative perturbation larger than -1.5 Wm{sup -2} is investigated by composite analysis. Post-eruption oceanic and atmospheric anomalies coherently describe a fluctuation in the coupled ocean-atmosphere system with an average length of 20-25 years. The study provides a new physically consistent theoretical framework to interpret decadal Northern Hemisphere (NH) regional winter climates variability during the last millennium. The fluctuation particularly involves interactions between the Atlantic meridional overturning circulation and the North Atlantic gyre circulation closely linked to the state of the winter North Atlantic Oscillation. It is characterized by major distinctive details. Among them, the most prominent are: (a) a strong signal amplification in the Arctic region which allows for a sustained strengthened teleconnection between the North Pacific and the North Atlantic during the first post-eruption decade and which entails important implications from oceanic heat transport and from post-eruption sea ice dynamics, and (b) an anomalous surface winter warming emerging over the Scandinavian/Western Russian region around 10-12 years after a major eruption. The simulated long-term climate response to SVEs depends, to some extent, on background conditions. Consequently, ensemble simulations spanning different phases of background multidecadal and longer climate variability are necessary to constrain the range of possible post-eruption decadal evolution of NH regional winter climates. (orig.)

  3. Impact of a realistic river routing in coupled ocean-atmosphere simulations of the Last Glacial Maximum climate

    Energy Technology Data Exchange (ETDEWEB)

    Alkama, Ramdane [IPSL, Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette Cedex (France); Universite Pierre et Marie Curie, Structure et fonctionnement des systemes hydriques continentaux (Sisyphe), Paris (France); Kageyama, M.; Ramstein, G.; Marti, O.; Swingedouw, D. [IPSL, Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette Cedex (France); Ribstein, P. [Universite Pierre et Marie Curie, Structure et fonctionnement des systemes hydriques continentaux (Sisyphe), Paris (France)

    2008-06-15

    The presence of large ice sheets over North America and North Europe at the Last Glacial Maximum (LGM) strongly impacted Northern hemisphere river pathways. Despite the fact that such changes may significantly alter the freshwater input to the ocean, modified surface hydrology has never been accounted for in coupled ocean-atmosphere general circulation model simulations of the LGM climate. To reconstruct the LGM river routing, we use the ICE-5G LGM topography. Because of the uncertainties in the extent of the Fennoscandian ice sheet in the Eastern part of the Kara Sea, we consider two more realistic river routing scenarios. The first scenario is characterised by the presence of an ice dammed lake south of the Fennoscandian ice sheet, and corresponds to the ICE-5G topography. This lake is fed by the Ob and Yenisei rivers. In the second scenario, both these rivers flow directly into the Arctic Ocean, which is more consistent with the latest QUEEN ice sheet margin reconstructions. We study the impact of these changes on the LGM climate as simulated by the IPSL{sub C}M4 model and focus on the overturning thermohaline circulation. A comparison with a classical LGM simulation performed using the same model and modern river basins as designed in the PMIP2 exercise leads to the following conclusions: (1) The discharge into the North Atlantic Ocean is increased by 2,000 m{sup 3}/s between 38 and 54 N in both simulations that contain LGM river routing, compared to the classical LGM experiment. (2) The ice dammed lake is shown to have a weak impact, relative to the classical simulation, both in terms of climate and ocean circulation. (3) In contrast, the North Atlantic deep convection and meridional overturning are weaker than during the classical LGM run if the Ob and Yenisei rivers flow directly into the Arctic Ocean. The total discharge into the Arctic Ocean is increased by 31,000 m{sup 3}/s, relative to the classical LGM simulation. Consequentially, northward ocean heat

  4. Influence of various forcings on global climate in historical times using a coupled atmosphere-ocean general circulation model

    DEFF Research Database (Denmark)

    Stendel, Martin; Mogensen, Irene A.; Christensen, Jens H.

    2006-01-01

    The results of a simulation of the climate of the last five centuries with a state-of-the-art coupled atmosphere-ocean general circulation model are presented. The model has been driven with most relevant forcings, both natural (solar variability, volcanic aerosol) and anthropogenic (greenhouse...... gases, sulphate aerosol, land-use changes). In contrast to previous GCM studies, we have taken into account the latitudinal dependence of volcanic aerosol and the changing land cover for a period covering several centuries. We find a clear signature of large volcanic eruptions in the simulated...

  5. Cosmogenic 32P and 33P in the Atmosphere and Oligotrophic Ocean and Applications to the Study of Phosphorus Cycling

    Science.gov (United States)

    1993-02-01

    Ed.) , pp53-82. Poet, S.E., Moore H.E., and EA. Martell, 1972. Lead- 210 , bismuth 210 and polonium 210 in the atmosphere: accurate ratio measurement...in the ocean food web. The residence time of P in macrozooplankton was estimated to range from 40 to 60 days. A grazing rate of macrozooplankton of...A.F and M.W. Silver, 1988. Primary production, sinking fluxes and the microbial food web. Deep Sea Res., 35:473-490. Perry, M. J. and R. W. Eppley

  6. Development of a GPS buoy system for monitoring tsunami, sea waves, ocean bottom crustal deformation and atmospheric water vapor

    Science.gov (United States)

    Kato, Teruyuki; Terada, Yukihiro; Nagai, Toshihiko; Koshimura, Shun'ichi

    2010-05-01

    bottom positions with a few centimeters in accuracy. The system is now operational for more than ten sites along the Japanese coasts. Currently, however, the measurements are not continuous but have been done once to several times a year using a boat. If a GPS and acoustic system is placed on a buoy, ocean bottom position could be monitored in near real-time and continuous manner. This will allow us to monitor more detailed and short term crustal deformations at the sea bottom. Another application plan is for an atmospheric research. Previous researchers have shown that GPS is capable of measuring atmospheric water vapor through estimating tropospheric zenith delay measurements of GPS at the sea surface. Information of water vapor content and its temporal variation over sea surface will much contribute to weather forecast on land which has mostly been conducted only by land observations. Considering that the atmospheric mass moves from west to east in general in and around Japanese islands, information of water vapor together with other atmospheric data from an array of GPS buoy placed in the west of Japanese Islands, will much improve weather forecast. We try to examine if this is also feasible. As a conclusion of a series of GPS buoy experiments, we could assert that GPS buoy system will be a powerful tool to monitor ocean surface and much contribute to provide safe and secure life of people.

  7. LIFETIME AND SPECTRAL EVOLUTION OF A MAGMA OCEAN WITH A STEAM ATMOSPHERE: ITS DETECTABILITY BY FUTURE DIRECT IMAGING

    Energy Technology Data Exchange (ETDEWEB)

    Hamano, Keiko; Kawahara, Hajime; Abe, Yutaka [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Onishi, Masanori [Department of Earth and Planetary Sciences, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501 (Japan); Hashimoto, George L., E-mail: keiko@eps.s.u-tokyo.ac.jp [Department of Earth Sciences, Okayama University, 3-1-1 Tsushima-Naka, Kita, Okayama, 700-8530 (Japan)

    2015-06-20

    We present the thermal evolution and emergent spectra of solidifying terrestrial planets along with the formation of steam atmospheres. The lifetime of a magma ocean and its spectra through a steam atmosphere depends on the orbital distance of the planet from the host star. For a Type I planet, which is formed beyond a certain critical distance from the host star, the thermal emission declines on a timescale shorter than approximately 10{sup 6} years. Therefore, young stars should be targets when searching for molten planets in this orbital region. In contrast, a Type II planet, which is formed inside the critical distance, will emit significant thermal radiation from near-infrared atmospheric windows during the entire lifetime of the magma ocean. The K{sub s} and L bands will be favorable for future direct imaging because the planet-to-star contrasts of these bands are higher than approximately 10{sup −7}–10{sup −8}. Our model predicts that, in the Type II orbital region, molten planets would be present over the main sequence of the G-type host star if the initial bulk content of water exceeds approximately 1 wt%. In visible atmospheric windows, the contrasts of the thermal emission drop below 10{sup −10} in less than 10{sup 5} years, whereas those of the reflected light remain 10{sup −10} for both types of planets. Since the contrast level is comparable to those of reflected light from Earth-sized planets in the habitable zone, the visible reflected light from molten planets also provides a promising target for direct imaging with future ground- and space-based telescopes.

  8. Tropical cyclones in two atmospheric (re)analyses and their response in two oceanic reanalyses

    Digital Repository Service at National Institute of Oceanography (India)

    Jourdain, N.C.; Barnier, B.; Ferry, N.; Vialard, J.; Menkes, C.E.; Lengaigne, M.; Parent, L.

    composites in Fig. 7). We focus our description of the mechanisms on strong TCs in GLORYS1 to emphasize the major issues in the ocean reanalyses, and GLORYS2 is not shown because it has a very similar temperature response to GLORYS1. In the top 30 m and over...

  9. South African mid-summer seasonal rainfall prediction performance by a coupled ocean-atmosphere model

    CSIR Research Space (South Africa)

    Landman, WA

    2011-01-01

    Full Text Available . 2000; Goddard and Mason, 2002). Such a so-called two-tiered procedure to predict the outcome of the rainfall season has been employed in South Africa for a number of years already (e.g., Landman et al., 2001). The advent of fully coupled ocean...

  10. Atmospheric deposition and surface stratification as controls of contrasting chlorophyll abundance in the North Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Patra, P.K.; DileepKumar, M.; Mahowald, N.; Sarma, V.V.S.S.

    Intense upwelling during summer and convection in winter are believed to drive higher biological productivity in the Arabian Sea than in the Bay of Bengal. Although the Arabian Sea receives substantial atmospheric deposition of dust aerosols, its...

  11. Atmospheric research in Southern Africa and Indian Ocean: a South Africa-France bilateral collaborative programme

    CSIR Research Space (South Africa)

    Sivakumar, V

    2009-09-01

    Full Text Available to be employed, university or institutes involved and French and South African co-ordinators for investigating the structure and dynamics of the atmosphere by utilising different in-situ, space-borne and model simulation techniques....

  12. Understanding the nature of atmospheric acid processing of mineral dusts in supplying bioavailable phosphorus to the oceans.

    Science.gov (United States)

    Stockdale, Anthony; Krom, Michael D; Mortimer, Robert J G; Benning, Liane G; Carslaw, Kenneth S; Herbert, Ross J; Shi, Zongbo; Myriokefalitakis, Stelios; Kanakidou, Maria; Nenes, Athanasios

    2016-12-20

    Acidification of airborne dust particles can dramatically increase the amount of bioavailable phosphorus (P) deposited on the surface ocean. Experiments were conducted to simulate atmospheric processes and determine the dissolution behavior of P compounds in dust and dust precursor soils. Acid dissolution occurs rapidly (seconds to minutes) and is controlled by the amount of H + ions present. For H + 10 -4 mol/g of dust, the amount of P (and calcium) released has a direct proportionality to the amount of H + consumed until all inorganic P minerals are exhausted and the final pH remains acidic. Once dissolved, P will stay in solution due to slow precipitation kinetics. Dissolution of apatite-P (Ap-P), the major mineral phase in dust (79-96%), occurs whether calcium carbonate (calcite) is present or not, although the increase in dissolved P is greater if calcite is absent or if the particles are externally mixed. The system was modeled adequately as a simple mixture of Ap-P and calcite. P dissolves readily by acid processes in the atmosphere in contrast to iron, which dissolves more slowly and is subject to reprecipitation at cloud water pH. We show that acidification can increase bioavailable P deposition over large areas of the globe, and may explain much of the previously observed patterns of variability in leachable P in oceanic areas where primary productivity is limited by this nutrient (e.g., Mediterranean).

  13. Complete synthetic seismograms based on a spherical self-gravitating Earth model with an atmosphere-ocean-mantle-core structure

    Science.gov (United States)

    Wang, Rongjiang; Heimann, Sebastian; Zhang, Yong; Wang, Hansheng; Dahm, Torsten

    2017-09-01

    A hybrid method is proposed to calculate complete synthetic seismograms based on a spherically symmetric and self-gravitating Earth with a multilayered structure of atmosphere, ocean, mantle, liquid core and solid core. For large wavelengths, a numerical scheme is used to solve the geodynamic boundary-value problem without any approximation on the deformation and gravity coupling. With decreasing wavelength, the gravity effect on the deformation becomes negligible and the analytical propagator scheme can be used. Many useful approaches are used to overcome the numerical problems that may arise in both analytical and numerical schemes. Some of these approaches have been established in the seismological community and the others are developed for the first time. Based on the stable and efficient hybrid algorithm, an all-in-one code QSSP is implemented to cover the complete spectrum of seismological interests. The performance of the code is demonstrated by various tests including the curvature effect on teleseismic body and surface waves, the appearance of multiple reflected, teleseismic core phases, the gravity effect on long period surface waves and free oscillations, the simulation of near-field displacement seismograms with the static offset, the coupling of tsunami and infrasound waves, and free oscillations of the solid Earth, the atmosphere and the ocean. QSSP is open source software that can be used as a stand-alone FORTRAN code or may be applied in combination with a Python toolbox to calculate and handle Green's function databases for efficient coding of source inversion problems.

  14. Global existence and regularity for the 3D stochastic primitive equations of the ocean and atmosphere with multiplicative white noise

    Science.gov (United States)

    Debussche, A.; Glatt-Holtz, N.; Temam, R.; Ziane, M.

    2012-07-01

    The primitive equations (PEs) are a basic model in the study of large scale oceanic and atmospheric dynamics. These systems form the analytical core of the most advanced general circulation models. For this reason and due to their challenging nonlinear and anisotropic structure, the PEs have recently received considerable attention from the mathematical community. On the other hand, in view of the complex multi-scale nature of the earth's climate system, many uncertainties appear that should be accounted for in the basic dynamical models of atmospheric and oceanic processes. In the climate community stochastic methods have come into extensive use in this connection. For this reason there has appeared a need to further develop the foundations of nonlinear stochastic partial differential equations in connection with the PEs and more generally. In this work we study a stochastic version of the PEs. We establish the global existence and uniqueness of strong, pathwise solutions for these equations in dimension 3 for the case of a nonlinear multiplicative noise. The proof makes use of anisotropic estimates, L^{p}_{t}L^{q}_{x} estimates on the pressure and stopping time arguments.

  15. Global existence and regularity for the 3D stochastic primitive equations of the ocean and atmosphere with multiplicative white noise

    International Nuclear Information System (INIS)

    Debussche, A; Glatt-Holtz, N; Temam, R; Ziane, M

    2012-01-01

    The primitive equations (PEs) are a basic model in the study of large scale oceanic and atmospheric dynamics. These systems form the analytical core of the most advanced general circulation models. For this reason and due to their challenging nonlinear and anisotropic structure, the PEs have recently received considerable attention from the mathematical community. On the other hand, in view of the complex multi-scale nature of the earth's climate system, many uncertainties appear that should be accounted for in the basic dynamical models of atmospheric and oceanic processes. In the climate community stochastic methods have come into extensive use in this connection. For this reason there has appeared a need to further develop the foundations of nonlinear stochastic partial differential equations in connection with the PEs and more generally. In this work we study a stochastic version of the PEs. We establish the global existence and uniqueness of strong, pathwise solutions for these equations in dimension 3 for the case of a nonlinear multiplicative noise. The proof makes use of anisotropic estimates, L p t L q x estimates on the pressure and stopping time arguments

  16. Oceanic and atmospheric conditions associated with the pentad rainfall over the southeastern peninsular India during the North-East Indian Monsoon season

    Science.gov (United States)

    Shanmugasundaram, Jothiganesh; Lee, Eungul

    2018-03-01

    The association of North-East Indian Monsoon rainfall (NEIMR) over the southeastern peninsular India with the oceanic and atmospheric conditions over the adjacent ocean regions at pentad time step (five days period) was investigated during the months of October to December for the period 1985-2014. The non-parametric correlation and composite analyses were carried out for the simultaneous and lagged time steps (up to four lags) of oceanic and atmospheric variables with pentad NEIMR. The results indicated that NEIMR was significantly correlated: 1) positively with both sea surface temperature (SST) led by 1-4 pentads (lag 1-4 time steps) and latent heat flux (LHF) during the simultaneous, lag 1 and 2 time steps over the equatorial western Indian Ocean, 2) positively with SST but negatively with LHF (less heat flux from ocean to atmosphere) during the same and all the lagged time steps over the Bay of Bengal. Consistently, during the wet NEIMR pentads over the southeastern peninsular India, SST significantly increased over the Bay of Bengal during all the time steps and the equatorial western Indian Ocean during the lag 2-4 time steps, while the LHF decreased over the Bay of Bengal (all time steps) and increased over the Indian Ocean (same, lag 1 and 2). The investigation on ocean-atmospheric interaction revealed that the enhanced LHF over the equatorial western Indian Ocean was related to increased atmospheric moisture demand and increased wind speed, whereas the reduced LHF over the Bay of Bengal was associated with decreased atmospheric moisture demand and decreased wind speed. The vertically integrated moisture flux and moisture transport vectors from 1000 to 850 hPa exhibited that the moisture was carried away from the equatorial western Indian Ocean to the strong moisture convergence regions of the Bay of Bengal during the same and lag 1 time steps of wet NEIMR pentads. Further, the moisture over the Bay of Bengal was transported to the southeastern peninsular

  17. Changing characteristics of streamflow in the Midwest and its relation to oceanic-atmospheric oscillations

    Science.gov (United States)

    Thakur, B.; Pathak, P.; Kalra, A.; Ahmad, S.

    2016-12-01

    The identification of primary drivers of streamflow may prove beneficial in forecasting streamflow in the Midwestern U.S. In the past researches, streamflow in the region have been strongly correlated with El Niño-Southern Oscillation (ENSO), Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO). The present study takes in to account the pre-defined Pacific and Atlantic Ocean regions (e.g., ENSO, PDO, AMO) along with new regions with an intent to identify new significantly correlated regions. This study assesses the interrelationship between sea surface temperatures (SST) anomalies in the Pacific and Atlantic Ocean and seasonal streamflow in the Midwestern U.S. Average Pacific and Atlantic Ocean SST anomalies, were calculated for 2 different 3 month series: September-November and December-February so as to create a lead time varying from 3 to 9 months. Streamflow were averaged for three seasons: spring (April-June), spring-summer (April-August) and summer (June-August). The correlation between streamflow and SST is analyzed using singular value decomposition for a period of 1960-2013. The result of the study showed several regions-other than the known Pacific and Atlantic Ocean regions- that were significantly correlated with streamflow stations. Higher correlation between the climate indices and streamflow were observed as the lead time decreased. The identification of the associations between SST and streamflow and significant SST regions in the Pacific and Atlantic Ocean may enhance the skill of streamflow predictability and water management in the region.

  18. Causes and consequences of mid–21st-century rapid ice loss events simulated by the Rossby centre regional atmosphere-ocean model

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Paquin

    2013-08-01

    Full Text Available Recent observations and modelling studies suggest that the Arctic climate is undergoing important transition. One manifestation of this change is seen in the rapid sea-ice cover decrease as experienced in 2007 and 2012. Although most numerical climate models cannot adequately reproduce the recent changes, some models produce similar Rapid Ice Loss Events (RILEs during the mid–21st-century. This study presents an analysis of four specific RILEs clustered around 2040 in three transient climate projections performed with the coupled Rossby Centre regional Atmosphere-Ocean model (RCAO. The analysis shows that long-term thinning causes increased vulnerability of the Arctic Ocean sea-ice cover. In the Atlantic sector, pre-conditioning (thinning of sea ice combined with anomalous atmospheric and oceanic heat transport causes large ice loss, while in the Pacific sector of the Arctic Ocean sea-ice albedo feedback appears important, particularly along the retreating sea-ice margin. Although maximum sea-ice loss occurs in the autumn, response in surface air temperature occurs in early winter, caused by strong increase in ocean-atmosphere surface energy fluxes, mainly the turbulent fluxes. Synchronicity of the events around 2040 in the projections is caused by a strong large-scale atmospheric circulation anomaly at the Atlantic lateral boundary of the regional model. The limited impact on land is caused by vertical propagation of the surface heat anomaly rather than horizontal, caused by the absence of low-level temperature inversion over the ocean.

  19. Ocean to continent transfer of atmospheric Se as revealed by epiphytic lichens

    International Nuclear Information System (INIS)

    Wen Hanjie; Carignan, Jean

    2009-01-01

    There is still a long-term debate concerning the relative contributions of naturally emitted and anthropogenic Se at the regional and local scales. Here, Se and heavy metal concentrations are reported for epiphytic lichens collected in coastal and inland areas from the USA, Canada and France for assessing atmospheric Se source. Correlations found between Se and Cl in lichens confirmed the major marine biogenic source for atmospheric Se. Continental samples do not show systematic relationships between Se and other metal (Pb, Cu, In ...) contents, even for lichens collected in the vicinity of smelters or close to urban areas. Our results suggest that, although anthropogenic Se may be present, the marine biogenic Se source is a major contributor to atmospheric Se for our sampling locations. The contribution of naturally emitted atmospheric Se may be significant in urban and industrial areas and should be taken into account for further studies. - Although anthropogenic Se may be present, the contribution of naturally emitted atmospheric Se may be significant in urban and industrial areas and should be taken into account for further studies.

  20. Atlantic multidecadal oceanic variability and its influence on the atmosphere in a climate model

    Energy Technology Data Exchange (ETDEWEB)

    Msadek, Rym; Frankignoul, Claude [Universite Pierre et Marie Curie, Paris 6, LOCEAN/IPSL, Paris (France)

    2009-07-15

    The mechanisms controlling the decadal to multidecadal variability of the Atlantic Meridional Overturning Circulation (MOC) and its influence on the atmosphere are investigated using a control simulation with the IPSL-CM4 climate model. The multidecadal fluctuations of the MOC are mostly driven by deep convection in the subpolar gyre, which occurs south of Iceland in the model. The latter is primarily influenced by the anomalous advection of salinity due to changes in the East Atlantic Pattern (EAP), which is the second mode of atmospheric variability in the North Atlantic region. The North Atlantic Oscillation is the dominant mode, but it plays a secondary role in the MOC fluctuations. During summer, the MOC variability is shown to have a significant impact on the atmosphere in the North Atlantic-European sector. The MOC influence is due to an interhemispheric sea surface temperature (SST) anomaly with opposite signs in the two hemispheres but largest amplitude in the northern one. The SST pattern driven by the MOC mostly resembles the model Atlantic Multidecadal Oscillation (AMO) and bears some similarity with the observed one. It is shown that the AMO reflects both the MOC influence and the local atmospheric forcing. Hence, the MOC influence on climate is best detected using lagged relations between climatic fields. The atmospheric response resembles the EAP, in a phase that might induce a weak positive feedback on the MOC. (orig.)

  1. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from SAMUDERA in the Molucca Sea, Indian Ocean and other waters from 1973-03-06 to 1993-03-27 (NODC Accession 9700146)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton, phytoplankton, nutrients, and other data were collected from bottle and net casts in the Pacific Ocean (Indonesia) from the Samudera from 06 March 1973...

  2. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from DISCOVERY and CHARLES DARWIN in the NE Atlantic, North Atlantic Ocean and Norwegian Sea from 1988-05-21 to 1990-07-20 (NODC Accession 9600083)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Conductivity, Temperature and Depth (CTD) and other data were collected in NE Atlantic (limit-40 W) as part of Global Ocean Data Archeaology and Rescue (GODAR)...

  3. Temperature profile and other data collected using microstructure profiler (JMSP) from the HAKUHO-MARU as part of the Coupled Ocean-Atmosphere Response Experiment (COARE), from 01 November 1992 - 30 November 1992 (NODC Accession 9600028)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and other data were collected using microstructure profiler (JMSP) from the HAKUHO-MARU in the TOGA Area - Pacific Ocean (30 N to 30 S) from...

  4. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from AIRCRAFT and ATLANTIS II in the North Atlantic Ocean from 1989-04-21 to 1992-04-15 (NODC Accession 9200089)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The accession contains Bathythermograph (XBT and Aerial XBT) data collected as part of Joint Global Ocean Flux Study (JGOFS) / North Atlantic Bloom Survey (NABS)in...

  5. The Navy’s Coupled Atmosphere-Ocean-Wave Prediction System

    Science.gov (United States)

    2011-04-15

    7300 Security, Code 1226 Office of Counsel,Code 1008.3 ADOR/Director NCST E. R. Franchi , 7000 Public Affairs (Unclassified/ Unlimited Only...Office as both a global model and relocatable regional model. The wave components of the system are run operationally at production centers at both...utilizes meteorological observations including radiosondes, satellite data, ship reports, and ocean observations with time-dependent global

  6. International Symposium on Acoustic Remote Sensing of the Atmosphere and Oceans (2nd).

    Science.gov (United States)

    1983-09-26

    work to develop a model the volume wave to form the boundary which relates hydrodynamical features of 6 ~A the ocean-air interface to ambient noise...is my belief oscillating bubbles, splashing waves and that the sodar work is not well known in water droplets, bubble cavitation , the Navy acoustics...Temperature," in accumulate in the same locations. Major Proceedings, InternationaZ Symposi- pollutants include oil spills, drilling w on Remote Sensing of

  7. Atmospheric, Non-Tidal Oceanic and Hydrological Loading Effects Observed with GPS Measurements

    Science.gov (United States)

    Boy, J. P.; Memin, A.; Watson, C.; Tregoning, P.

    2014-12-01

    The Copernicus Programme, being Europe's Earth Observation and Monitoring Programme led by the European Union, aims to provide, on a sustainable basis, reliable and timely services related to environmental and security issues. The Sentinel-3 mission forms part of the Copernicus Space Component. Its main objectives, building on the heritage and experience of the European Space Agency's (ESA) ERS and ENVISAT missions, are to measure sea-surface topography, sea- and land-surface temperature and ocean- and land-surface colour in support of ocean forecasting systems, and for environmental and climate monitoring. The series of Sentinel-3 satellites will ensure global, frequent and near-real time ocean, ice and land monitoring, with the provision of observation data in routine, long term (up to 20 years of operations) and continuous fashion, with a consistent quality and a high level of reliability and availability. The Sentinel-3 missions will be jointly operated by ESA and EUMETSAT. ESA will be responsible for the operations, maintenance and evolution of the Sentinel-3 ground segment on land related products and EUMETSAT for the marine products. The Sentinel-3 ground segment systematically acquires, processes and distributes a set of pre-defined core data products. Sentinel-3A is foreseen to be launched at the beginning of November 2015. The paper will give an overview on the mission, its instruments and objectives, the data products provided, the mechanisms to access the mission's data, and if available first results.

  8. Oasis dynamics change and its influence on landscape pattern on Jinta oasis in arid China from 1963a to 2010a: Integration of multi-source satellite images

    Science.gov (United States)

    Xie, Yuchu; Gong, Jie; Sun, Peng; Gou, Xiaohua

    2014-12-01

    As one of the vital research highlights of global land use and cover change, oasis change and its interaction with landscape pattern have been regarded as an important content of regional environmental change research in arid areas. Jinta oasis, a typical agricultural oasis characterized by its dramatic exploitation and use of water and land resources in Hexi corridor, northwest arid region in China, was selected as a case to study the spatiotemporal oasis change and its effects on oasis landscape pattern. Based on integration of Keyhole satellite photographs, KATE-200 photographs, Landsat MSS, TM and ETM+ images, we evaluated and analyzed the status, trend and spatial pattern change of Jinta oasis and the characteristics of landscape pattern change by a set of mathematical models and combined this information with landscape metrics and community surveys. During the period of 1963a-2010a, Jinta oasis expanded gradually with an area increase of 219.15 km2, and the conversion between oasis and desert was frequent with a state of “imbalance-balance-extreme imbalance conditions”. Moreover, most of the changes took place in the ecotone between oasis and desert and the interior of oasis due to the reclamation of abandoned land, such as Yangjingziwan and Xiba townships. Furthermore, the area, size and spatial distribution of oasis were influenced by human activities and resulted in fundamental changes of oasis landscape pattern. The fractal characteristics, dispersion degree and fragmentation of Jinta oasis decreased and the oasis landscape tended to be simple and uniform. Oasis change trajectories and its landscape pattern were mainly influenced by water resource utilization, policies (especially land policies), demographic factors, technological advancements, as well as regional economic development. We found that time series analysis of multi-source remote sensing images and the application of an oasis change model provided a useful approach to monitor oasis change

  9. Validation of SWEEP for creep, saltation, and suspension in a desert-oasis ecotone

    Science.gov (United States)

    Wind erosion in the desert-oasis ecotone can accelerate desertification and thus impacts oasis ecological security. Little is known about the susceptibility of the desert-oasis ecotone to wind erosion in the Tarim Basin even though the ecotone is a major source of windblown dust in China. The object...

  10. Deuterium in the water cycle of the Schirmacher Oasis (Dronning Maud Land, East Antarctica). A data compilation

    International Nuclear Information System (INIS)

    Kowski, P.; Richter, W.

    1988-01-01

    The Schirmacher Oasis (Dronning Maud Land) - one of the rock deserts of the South Polar region - is situated on the coast of the Antarctic continent, between inland and shelf ice. The data compilation contains results of deuterium studies from different parts of the local water cycle and is arranged according to the main parts: precipitation and atmospheric moisture, both collected near Novolazarevskaya Station, lake water, surface snow and ice, shallow drill cores of snow and ice, and from melt water runoff. Finally, monthly means of precipitation and atmospheric moisture are given. (author)

  11. Southern hemisphere climate variability as represented by an ocean-atmosphere coupled model

    CSIR Research Space (South Africa)

    Beraki, A

    2012-09-01

    Full Text Available in the atmospheric circulation. The ability of predicting these modes of climate variability on longer timescales is vital. Potential predictability is usually measured as a signal-to-noise contrast between the slowly evolving and chaotic components of the climate...

  12. Evaluation of Shortwave Infrared Atmospheric Correction for Ocean Color Remote Sensing of Chesapeake Bay

    Science.gov (United States)

    Werdell, P. Jeremy; Franz, Bryan A.; Bailey, Sean W.

    2010-01-01

    The NASA Moderate Resolution Imaging Spectroradiometer onboard the Aqua platform (MODIS-Aqua) provides a viable data stream for operational water quality monitoring of Chesapeake Bay. Marine geophysical products from MODIS-Aqua depend on the efficacy of the atmospheric correction process, which can be problematic in coastal environments. The operational atmospheric correction algorithm for MODIS-Aqua requires an assumption of negligible near-infrared water-leaving radiance, nL(sub w)(NIR). This assumption progressively degrades with increasing turbidity and, as such, methods exist to account for non-negligible nL(sub w)(NIR) within the atmospheric correction process or to use alternate radiometric bands where the assumption is satisfied, such as those positioned within shortwave infrared (SWIR) region of the spectrum. We evaluated a decade-long time-series of nL(sub w)(lambda) from MODIS-Aqua in Chesapeake Bay derived using NIR and SWIR bands for atmospheric correction. Low signal-to-noise ratios (SNR) for the SWIR bands of MODIS-Aqua added noise errors to the derived radiances, which produced broad, flat frequency distributions of nL(sub w)(lambda) relative to those produced using the NIR bands. The SWIR approach produced an increased number of negative nL(sub w)(lambda) and decreased sample size relative to the NIR approach. Revised vicarious calibration and regional tuning of the scheme to switch between the NIR and SWIR approaches may improve retrievals in Chesapeake Bay, however, poor SNR values for the MODIS-Aqua SWIR bands remain the primary deficiency of the SWIR-based atmospheric correction approach.

  13. Oasis-an innovative system for alpha spectroscopy

    International Nuclear Information System (INIS)

    Seymour, R.; Richards, W.; Knight, K.; El-Sayad, G.

    1995-01-01

    Until recently, instrumental alpha spectroscopy has behind the technical developments of instrumentation and software that are available for low background o c/ counting, liquid scintillation, and gamma spectroscopy instruments. We report in this paper, the development of Oasis, a new family of alpha spectroscopy systems from oxford instruments Inc., Nuclear measurements Group. The Oasis instruments incorporate many hardware and software innovations providing an automated and integrated production environment for alpha spectroscopy. These instruments are needed because of the large number of samples to be measured and the required throughput of production laboratories processing these samples. Oasis is also useful for facilities because of their sophisticated vacuum control, management, and analysis features. One of the most important innovations is the electronic vacuum system and cartesian diver. Many additional features contribute to improving accuracy, lowering cost per sample, improving sample throughput, and ensuring accountability of laboratory results. 5 figs

  14. Oasis-an innovative system for alpha spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Seymour, R; Richards, W; Knight, K; El-Sayad, G [Oxford Instruments Inc., P.O. Box 2560, Oak Ridge, TN 37831-2560 (United States)

    1995-10-01

    Until recently, instrumental alpha spectroscopy has behind the technical developments of instrumentation and software that are available for low background o c/ counting, liquid scintillation, and gamma spectroscopy instruments. We report in this paper, the development of Oasis, a new family of alpha spectroscopy systems from oxford instruments Inc., Nuclear measurements Group. The Oasis instruments incorporate many hardware and software innovations providing an automated and integrated production environment for alpha spectroscopy. These instruments are needed because of the large number of samples to be measured and the required throughput of production laboratories processing these samples. Oasis is also useful for facilities because of their sophisticated vacuum control, management, and analysis features. One of the most important innovations is the electronic vacuum system and cartesian diver. Many additional features contribute to improving accuracy, lowering cost per sample, improving sample throughput, and ensuring accountability of laboratory results. 5 figs.

  15. Can an Atmospherically Forced Ocean Model Accurately Simulate Sea Surface Temperature During ENSO Events?

    Science.gov (United States)

    2010-01-01

    Ruth H. Preller, 7300 Security, Code 1226 Office of Counsel.Code 1008.3 ADOR/Director NCST E. R. Franchi , 7000 Public Affairs (Unclassified...Ruth H. Prellcr. 7300 Security. Code 1226 Office nl Cot nsal.Co’de’""" 10OB.3 ADORfOireMO,’ NCST. E. R. Franchi , 7000 Public Affairs ftMCl»SS/»d...over the global ocean. Similarly, the monthly mean MODAS SST climatology is based on Advanced Very-High Resolution Radiometer (AVHRR) Multi

  16. On the relationship between the early spring Indian Ocean's sea surface temperature (SST) and the Tibetan Plateau atmospheric heat source in summer

    Science.gov (United States)

    Ji, Chenxu; Zhang, Yuanzhi; Cheng, Qiuming; Li, Yu; Jiang, Tingchen; San Liang, X.

    2018-05-01

    In this study, we evaluated the effects of springtime Indian Ocean's sea surface temperature (SST) on the Tibetan Plateau's role as atmospheric heat source (AHS) in summer. The SST data of the National Oceanic and Atmospheric Administration (NOAA), European Centre for Medium-Range Weather Forecasts (ECMWF) and the Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST) and the reanalysis data of the National Center for Environmental Prediction (NCEP) and National Center for Atmospheric Research (NCAR) for 33 years (from 1979 to 2011) were used to analyze the relationship between the Indian Ocean SST and the Tibetan Plateau's AHS in summer, using the approaches that include correlation analysis, and lead-lag analysis. Our results show that some certain strong oceanic SSTs affect the summer plateau heat, specially finding that the early spring SSTs of the Indian Ocean significantly affect the plateau's ability to serve as a heat source in summer. Moreover, the anomalous atmospheric circulation and transport of water vapor are related to the Plateau heat variation.

  17. Fluxes of Ethanol Between the Atmosphere and Oceanic Surface Waters; Implications for the Fate of Biofuel Ethanol Released into the Environment

    Science.gov (United States)

    Avery, G. B., Jr.; Shimizu, M. S.; Willey, J. D.; Mead, R. N.; Skrabal, S. A.; Kieber, R. J.; Lathrop, T. E.; Felix, J. D. D.

    2017-12-01

    The use of ethanol as a transportation fuel has increased significantly during the past decade in the US. Some ethanol escapes the combustion process in internal combustion engines resulting in its release to the atmosphere. Ethanol can be oxidized photochemically to acetaldehyde and then converted to peroxyacetyl nitrate contributing to air pollution. Therefore it is important to determine the fate ethanol released to the atmosphere. Because of its high water solubility the oceans may act as a sink for ethanol depending on its state of saturation with respect to the gas phase. The purpose of the current study was to determine the relative saturation of oceanic surface waters by making simultaneous measurements of gas phase and surface water concentrations. Data were obtained from four separate cruises ranging from estuarine to open ocean locations in the coast of North Carolina, USA. The majority of estuarine sites were under saturated in ethanol with respect to the gas phase (11-50% saturated) representing a potential sink. Coastal surface waters tended to be supersaturated (135 - 317%) representing a net flux of ethanol to the atmosphere. Open ocean samples were generally at saturation or slightly below saturation (76-99%) indicating equilibrium between the gas and aqueous phases. The results of this study underscore to variable role the oceans play in mitigating the increases in atmospheric ethanol from increased biofuel usage and their impact on air quality.

  18. Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: A multi-model linear feedback analysis

    OpenAIRE

    Roy Tilla; Bopp Laurent; Gehlen Marion; Schneider Birgitt; Cadule Patricia; Frölicher Thomas; Segschneider Jochen; Tijputra Jerry; Heinze Christoph; Joos Fortunat

    2011-01-01

    The increase in atmospheric CO2 over this century depends on the evolution of the oceanic air–sea CO2 uptake which will be driven by the combined response to rising atmospheric CO2 itself and climate change. Here the future oceanic CO2 uptake is simulated using an ensemble of coupled climate–carbon cycle models. The models are driven by CO2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high emission scenario. A linear feedback analysis successfully sep...

  19. Role of upper-most crustal composition in the evolution of the Precambrian ocean-atmosphere system

    Science.gov (United States)

    Large, R. R.; Mukherjee, I.; Zhukova, I.; Corkrey, R.; Stepanov, A.; Danyushevsky, L. V.

    2018-04-01

    Recent research has emphasized the potential relationships between supercontinent cycles, mountain building, nutrient flux, ocean-atmosphere chemistry and the origin of life. The composition of the Upper-Most Continental Crust (UMCC) also figures prominently in these relationships, and yet little detailed data on each component of this complex relationship has been available for assessment. Here we provide a new set of data on the trace element concentrations, including the Rare Earth Elements (REE), in the matrix of 52 marine black shale formations spread globally through the Archean and Proterozoic. The data support previous studies on the temporal geochemistry of shales, but with some important differences. Results indicate a change in provenance of the black shales (upper-most crustal composition), from more mafic in the Archean prior to 2700 Ma, to more felsic from 2700 to 2200 Ma, followed by a return to mafic compositions from 2200 to 1850 Ma. Around 1850 to 1800 Ma there is a rapid change to uniform felsic compositions, which remained for a billion years to 800 Ma. The shale matrix geochemistry supports the assertion that the average upper-most continental source rocks for the shales changed from a mix of felsic, mafic and ultramafic prior to 2700 Ma to more felsic after 1850 Ma, with an extended transition period between. The return to more mafic UMCC from 2200 to 1850 Ma is supported by the frequency of Large Igneous Provinces (LIPs) and banded iron formations, which suggest a peak in major mantle-connected plume events and associated Fe-rich hydrothermal activity over this period. Support for the change to felsic UMCC around 1850 Ma is provided by previous geological data which shows that felsic magmas, including, A-type granites and K-Th-U-rich granites intruded vast areas of the continental crust, peaking around 1850 Ma and declining to 1000 Ma. The implications of this change in UMCC are far reaching and may go some way to explain the distinct

  20. Designing and Implementing a Computational Methods Course for Upper-level Undergraduates and Postgraduates in Atmospheric and Oceanic Sciences

    Science.gov (United States)

    Nelson, E.; L'Ecuyer, T. S.; Douglas, A.; Hansen, Z.

    2017-12-01

    In the modern computing age, scientists must utilize a wide variety of skills to carry out scientific research. Programming, including a focus on collaborative development, has become more prevalent in both academic and professional career paths. Faculty in the Department of Atmospheric and Oceanic Sciences at the University of Wisconsin—Madison recognized this need and recently approved a new course offering for undergraduates and postgraduates in computational methods that was first held in Spring 2017. Three programming languages were covered in the inaugural course semester and development themes such as modularization, data wrangling, and conceptual code models were woven into all of the sections. In this presentation, we will share successes and challenges in developing a research project-focused computational course that leverages hands-on computer laboratory learning and open-sourced course content. Improvements and changes in future iterations of the course based on the first offering will also be discussed.

  1. Effect of Gravity Waves from Small Islands in the Southern Ocean on the Southern Hemisphere Atmospheric Circulation

    Science.gov (United States)

    Garfinkel, C. I.; Oman, L. D.

    2018-01-01

    The effect of small islands in the Southern Ocean on the atmospheric circulation in the Southern Hemisphere is considered with a series of simulations using the NASA Goddard Earth Observing System Chemistry-Climate Model in which the gravity wave stress generated by these islands is increased to resemble observed values. The enhanced gravity wave drag leads to a 2 K warming of the springtime polar stratosphere, partially ameliorating biases in this region. Resolved wave drag declines in the stratospheric region in which the added orographic gravity waves deposit their momentum, such that changes in gravity waves are partially compensated by changes in resolved waves, though resolved wave drag increases further poleward. The orographic drag from these islands has impacts for surface climate, as biases in tropospheric jet position are also partially ameliorated. These results suggest that these small islands are likely contributing to the missing drag near 60 degrees S in the upper stratosphere evident in many data assimilation products.

  2. Ice at the Interface: Atmosphere-Ice-Ocean Boundary Layer Processes and Their Role in Polar Change---Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Hunke, Elizabeth C. [Los Alamos National Laboratory

    2012-07-23

    The atmosphere-ocean boundary layer in which sea ice resides includes many complex processes that require a more realistic treatment in GCMs, particularly as models move toward full earth system descriptions. The primary purpose of the workshop was to define and discuss such coupled processes from observational and modeling points of view, including insight from both the Arctic and Antarctic systems. The workshop met each of its overarching goals, including fostering collaboration among experimentalists, theorists and modelers, proposing modeling strategies, and ascertaining data availability and needs. Several scientific themes emerged from the workshop, such as the importance of episodic or extreme events, precipitation, stratification above and below the ice, and the marginal ice zone, whose seasonal Arctic migrations now traverse more territory than in the past.

  3. Comparison of length of day with oceanic and atmospheric angular momentum series

    Czech Academy of Sciences Publication Activity Database

    Kouba, J.; Vondrák, Jan

    2005-01-01

    Roč. 79, 4-5 (2005), s.256-268 ISSN 0949-7714 R&D Projects: GA AV ČR IAA3003205; GA MŠk LC506 Institutional research plan: CEZ:AV0Z10030501 Keywords : Earth rotation * length of day * atmospheric angular momentum Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.205, year: 2005

  4. Sea Salt Aerosol, Atmospheric Radon and Meteorological Observations in the Western South Atlantic Ocean (February 1981).

    Science.gov (United States)

    1983-09-28

    approximately isokinetic sampling conditions. The blower motor for the hi-vol was separated from the filter holder unit by a one- meter length of flexible...bridge bulkhead about 15 m above sea level and within 3 meters of the ARCAS inlet. The flow rate through the 20 cm x 25 cm glass fiber filters was...materials, atmospheric pressure, soil moisture and vegetative cover (Larson and Bressan, 1980). Radon concentrations measured a few meters above

  5. Analyzing coastal turbidity under complex terrestrial loads characterized by a 'stress connectivity matrix' with an atmosphere-watershed-coastal ocean coupled model

    Science.gov (United States)

    Yamamoto, Takahiro; Nadaoka, Kazuo

    2018-04-01

    Atmospheric, watershed and coastal ocean models were integrated to provide a holistic analysis approach for coastal ocean simulation. The coupled model was applied to coastal ocean in the Philippines where terrestrial sediment loads provided from several adjacent watersheds play a major role in influencing coastal turbidity and are partly responsible for the coastal ecosystem degradation. The coupled model was validated using weather and hydrologic measurement to examine its potential applicability. The results revealed that the coastal water quality may be governed by the loads not only from the adjacent watershed but also from the distant watershed via coastal currents. This important feature of the multiple linkages can be quantitatively characterized by a "stress connectivity matrix", which indicates the complex underlying structure of environmental stresses in coastal ocean. The multiple stress connectivity concept shows the potential advantage of the integrated modelling approach for coastal ocean assessment, which may also serve for compensating the lack of measured data especially in tropical basins.

  6. The interaction of the cretaceous-tertiary extinction bolide with the atmosphere, ocean, and solid earth

    Science.gov (United States)

    Okeefe, J. D.; Ahrens, T. J.

    1981-01-01

    A number of investigations, including those reported by Orth et al. (1981), have provided physical evidence for the impact of an extraterrestrial object on earth 65 million years ago. This time corresponds to the end of the cretaceous period. This impact could, therefore, be responsible for the observed extinction of biological species at the end of the Mesozoic era. Among the species becoming extinct are found also flying and walking dinosaurs, which include all land animals that had masses greater than 25 kg. The present investigation is concerned with a study of the possibilities for the collision of earth with 10 km-size object, and the consequences produced by such a collision. It is found that the penetration of the atmosphere by the bolide creates a temporary hole in the atmosphere. The resulting flow fields can inject melt droplets and finely commuted solid particles into the atmosphere. Short-term effects of heating, followed by dust induced worldwide cooling, may provide several mechanisms for the observed extinction of the species.

  7. Forcing of the wintertime atmospheric circulation by the multidecadal fluctuations of the North Atlantic ocean

    International Nuclear Information System (INIS)

    Peings, Yannick; Magnusdottir, Gudrun

    2014-01-01

    The North Atlantic sea surface temperature exhibits fluctuations on the multidecadal time scale, a phenomenon known as the Atlantic Multidecadal Oscillation (AMO). This letter demonstrates that the multidecadal fluctuations of the wintertime North Atlantic Oscillation (NAO) are tied to the AMO, with an opposite-signed relationship between the polarities of the AMO and the NAO. Our statistical analyses suggest that the AMO signal precedes the NAO by 10–15 years with an interesting predictability window for decadal forecasting. The AMO footprint is also detected in the multidecadal variability of the intraseasonal weather regimes of the North Atlantic sector. This observational evidence is robust over the entire 20th century and it is supported by numerical experiments with an atmospheric global climate model. The simulations suggest that the AMO-related SST anomalies induce the atmospheric anomalies by shifting the atmospheric baroclinic zone over the North Atlantic basin. As in observations, the positive phase of the AMO results in more frequent negative NAO—and blocking episodes in winter that promote the occurrence of cold extreme temperatures over the eastern United States and Europe. Thus, it is plausible that the AMO plays a role in the recent resurgence of severe winter weather in these regions and that wintertime cold extremes will be promoted as long as the AMO remains positive. (paper)

  8. Atmospheric pollutant and other data from the TRIDENT and tower as part of the International Decade of Ocean Exploration (IDOE) from 1972-02-01 to 1972-09-01 (NCEI Accession 7300574)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Atmospheric pollutant and other data were collected from the TRIDENT and tower from 01 February 1972 to 01 September 1972. Data include trace metals in the...

  9. Initiation of a Marinoan Snowball Earth in a state-of-the-art atmosphere-ocean general circulation model

    Directory of Open Access Journals (Sweden)

    A. Voigt

    2011-03-01

    Full Text Available We study the initiation of a Marinoan Snowball Earth (~635 million years before present with the state-of-the-art atmosphere-ocean general circulation model ECHAM5/MPI-OM. This is the most sophisticated model ever applied to Snowball initiation. A comparison with a pre-industrial control climate shows that the change of surface boundary conditions from present-day to Marinoan, including a shift of continents to low latitudes, induces a global-mean cooling of 4.6 K. Two thirds of this cooling can be attributed to increased planetary albedo, the remaining one third to a weaker greenhouse effect. The Marinoan Snowball Earth bifurcation point for pre-industrial atmospheric carbon dioxide is between 95.5 and 96% of the present-day total solar irradiance (TSI, whereas a previous study with the same model found that it was between 91 and 94% for present-day surface boundary conditions. A Snowball Earth for TSI set to its Marinoan value (94% of the present-day TSI is prevented by doubling carbon dioxide with respect to its pre-industrial level. A zero-dimensional energy balance model is used to predict the Snowball Earth bifurcation point from only the equilibrium global-mean ocean potential temperature for present-day TSI. We do not find stable states with sea-ice cover above 55%, and land conditions are such that glaciers could not grow with sea-ice cover of 55%. Therefore, none of our simulations qualifies as a "slushball" solution. While uncertainties in important processes and parameters such as clouds and sea-ice albedo suggest that the Snowball Earth bifurcation point differs between climate models, our results contradict previous findings that Snowball Earth initiation would require much stronger forcings.

  10. High-resolution ocean and atmosphere pCO2 time-series measurements from mooring WA_125W_47N in the North Pacific Ocean, US West Coast from 2006-06-23 to 2015-03-05 (NODC Accession 0115322)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0115322 includes chemical, meteorological, physical and time series data collected from MOORING_WA_125W_47N in the North Pacific Ocean, US West Coast...

  11. Dissolved methane in the Beaufort Sea and the Arctic Ocean, 1992-2009; sources and atmospheric flux

    Science.gov (United States)

    Lorenson, Thomas D.; Greinert, Jens; Coffin, Richard B.

    2016-01-01

    Methane concentration and isotopic composition was measured in ice-covered and ice-free waters of the Arctic Ocean during eleven surveys spanning the years of 1992-1995 and 2009. During ice-free periods, methane flux from the Beaufort shelf varies from 0.14 to 0.43 mg CH4 m-2 day-1. Maximum fluxes from localized areas of high methane concentration are up to 1.52 mg CH4 m-2 day-1. Seasonal buildup of methane under ice can produce short-term fluxes of methane from the Beaufort shelf that varies from 0.28 to 1.01 to mg CH4 m-2 day-1. Scaled-up estimates of minimum methane flux from the Beaufort Sea and pan-Arctic shelf for both ice-free and ice-covered periods range from 0.02 Tg CH4 yr-1 and 0.30 Tg CH4 yr-1 respectively to maximum fluxes of 0.18 Tg CH4 yr-1 and 2.2 Tg CH4 yr-1 respectively. A methane flux of 0.36 Tg CH4 yr-1from the deep Arctic Ocean was estimated using data from 1993-94. The flux can be as much as 2.35 Tg CH4 yr-1 estimated from maximum methane concentrations and wind speeds of 12 m/s, representing only 0.42% of the annual atmospheric methane budget of ~560 Tg CH4 yr-1. There were no significant changes in methane fluxes during the time period of this study. Microbial methane sources predominate with minor influxes from thermogenic methane offshore Prudhoe Bay and the Mackenzie River delta and may include methane from gas hydrate. Methane oxidation is locally important on the shelf and is a methane sink in the deep Arctic Ocean.

  12. The role of ocean-atmosphere interaction in Typhoon Sinlaku (2008) using a regional coupled data assimilation system

    Science.gov (United States)

    Wada, Akiyoshi; Kunii, Masaru

    2017-05-01

    For improving analyses of tropical cyclone (TC) and sea surface temperature (SST) and thereby TC simulations, a regional mesoscale strongly coupled atmosphere-ocean data assimilation system was developed with the local ensemble transform Kalman filter (LETKF) implemented with the Japan Meteorological Agency's nonhydrostatic model (NHM) coupled with a multilayer ocean model and the third-generation ocean wave model. The NHM-LETKF coupled data assimilation system was applied to Typhoon Sinlaku (2008) along with the original NHM-LETKF system to investigate the sensitivity of Sinlaku to SST assimilation with the Level 2 Pre-processed (L2P) standard product of satellite SST. SST calculated in the coupled-assimilation experiment with the coupled data assimilation system and the satellite SST (CPL) showed a better correlation with Optimally Interpolated SST than SST used in the control experiment with the original NHM-LETKF (CNTL) and SST calculated in the succession experiment with the coupled system without satellite SST (SUCC). The time series in the CPL experiment well captured the variation in the SST observed at the Kuroshio Extension Observation buoy site. In addition, TC-induced sea surface cooling was analyzed more realistically in the CPL experiment than that in the CNTL and SUCC experiments. However, the central pressure analyzed in each three experiments was overestimated compared with the Regional Specialized Meteorological Center Tokyo best-track central pressure, mainly due to the coarse horizontal resolution of 15 km. The 96 h TC simulations indicated that the CPL experiment provided more favorable initial and boundary conditions than the CNTL experiment to simulate TC tracks more accurately.

  13. Field measurements of the atmospheric dry deposition fluxes and velocities of polycyclic aromatic hydrocarbons to the global oceans.

    Science.gov (United States)

    González-Gaya, Belén; Zúñiga-Rival, Javier; Ojeda, María-José; Jiménez, Begoña; Dachs, Jordi

    2014-05-20

    The atmospheric dry deposition fluxes of 16 polycyclic aromatic hydrocarbons (PAHs) have been measured, for the first time, in the tropical and subtropical Atlantic, Pacific, and Indian Oceans. Depositional fluxes for fine (0.7-2.7 μm) and coarse (>2.7 μm) aerosol fractions were simultaneously determined with the suspended aerosol phase concentrations, allowing the determination of PAH deposition velocities (vD). PAH dry deposition fluxes (FDD) bound to coarse aerosols were higher than those of fine aerosols for 83% of the measurements. Average FDD for total (fine + coarse) Σ16PAHs (sum of 16 individual PAHs) ranged from 8.33 ng m(-2)d(-1) to 52.38 ng m(-2)d(-1). Mean FDD for coarse aerosol's individual PAHs ranged between 0.13 ng m(-2)d(-1) (Perylene) and 1.96 ng m(-2)d(-1) (Methyl Pyrene), and for the fine aerosol fraction these ranged between 0.06 ng m(-2)d(-1) (Dimethyl Pyrene) and 1.25 ng m(-2)d(-1) (Methyl Chrysene). The estimated deposition velocities went from the highest mean vD for Methyl Chrysene (0.17-13.30 cm s(-1)), followed by Dibenzo(ah)Anthracene (0.29-1.38 cm s(-1)), and other high MW PAHs to minimum values of vD for Dimethyl Pyrene (oceans.

  14. Observations of atmospheric lead-210 over the Atlantic Ocean and Antarctica during the FINNARP-1999/2999 Expedition

    International Nuclear Information System (INIS)

    Paatero, J.; Virkkula, A.; Hillamo, R.; Koponen, I.

    2002-01-01

    Physical and chemical properties of the atmosphere were measured in November-December 1999 onboard the Russian research vessel Akademik Fedorov over the Atlantic Ocean between the English Channel and the coast of Antarctica. After the cruise the measurements were continued in January 2000 at the Finnish research station Aboa (73 deg. 03'S, 13 deg. 25'W, 470 m above sea level) in Dronning Maud Land, Antarctica. The location of the station is about 170 km inland from the coast of Weddell Sea. The study is part of the Finnish Antarctic Research Programme (FINNARP) financed by the Academy of Finland. The observed 210 Pb activity concentrations in the air varied between 24 and 790 μBq/m 3 during the cruise between the English Channel and Cape town. The highest values were recorded close ( 210 Pb activity concentrations varied between 3 . At the research station Aboa the observed values varied between 3 . Between 6 and 11 January 2000 the air masses at Aboa originated from central regions of Antarctica according to the trajectory calculations made with the NORA Hysplit model. The concentrations were below detection limit between 11 and 14 January. These samples were connected to the air masses originating from the South Atlantic Ocean. Between 14 and 20 January air masses came to Aboa mainly from easterly direction from coastal and inland regions of the Antarctica. (LN)

  15. Time-slice analysis of the Australian summer monsoon during the late Quaternary using the Fast Ocean Atmosphere Model

    Science.gov (United States)

    Marshall, A. G.; Lynch, A. H.

    2006-10-01

    We use the Fast Ocean Atmosphere Model (FOAM) to investigate the variation in the Australian summer monsoon over the last 55 000 years. A synthesis of palaeoenvironmental observations is used to constrain the model for six time slices: 55, 35, 21, 11, 6 and 0 ka. Both inter-hemispheric forcing and the seasonal timing of local insolation changes play key, and interacting, roles on the evolution and intensity of the monsoon.During the onset to the monsoon, a heat low develops to the west of Australia over the Indian Ocean in all time slices, but with varying strengths. Divergent outflow from Asia converges with the cyclonic flow to bring increased rainfall to northern Australia and the maritime continent. The relative importance of a low pressure pull and the high pressure push varies according to the strength of the pressure anomalies. Only in the middle Holocene is the low pressure pull the dominant forcing mechanism. At 21 ka, the climate shift to colder mean temperatures determines the large-scale dynamics of the monsoon.The general picture that emerges from these results is consistent with available palaeodata but highlights the importance of a broad regional perspective to ascribe the driving mechanisms at different times. Copyright

  16. Biological production models as elements of coupled, atmosphere-ocean models for climate research

    Science.gov (United States)

    Platt, Trevor; Sathyendranath, Shubha

    1991-01-01

    Process models of phytoplankton production are discussed with respect to their suitability for incorporation into global-scale numerical ocean circulation models. Exact solutions are given for integrals over the mixed layer and the day of analytic, wavelength-independent models of primary production. Within this class of model, the bias incurred by using a triangular approximation (rather than a sinusoidal one) to the variation of surface irradiance through the day is computed. Efficient computation algorithms are given for the nonspectral models. More exact calculations require a spectrally sensitive treatment. Such models exist but must be integrated numerically over depth and time. For these integrations, resolution in wavelength, depth, and time are considered and recommendations made for efficient computation. The extrapolation of the one-(spatial)-dimension treatment to large horizontal scale is discussed.

  17. Antarctic lakes suggest millennial reorganizations of Southern Hemisphere atmospheric and oceanic circulation.

    Science.gov (United States)

    Hall, Brenda L; Denton, George H; Fountain, Andrew G; Hendy, Chris H; Henderson, Gideon M

    2010-12-14

    The phasing of millennial-scale oscillations in Antarctica relative to those elsewhere in the world is important for discriminating among models for abrupt climate change, particularly those involving the Southern Ocean. However, records of millennial-scale variability from Antarctica dating to the last glacial maximum are rare and rely heavily on data from widely spaced ice cores, some of which show little variability through that time. Here, we present new data from closed-basin lakes in the Dry Valleys region of East Antarctica that show high-magnitude, high-frequency oscillations in surface level during the late Pleistocene synchronous with climate fluctuations elsewhere in the Southern Hemisphere. These data suggest a coherent Southern Hemisphere pattern of climate change on millennial time scales, at least in the Pacific sector, and indicate that any hypothesis concerning the origin of these events must account for synchronous changes in both high and temperate latitudes.

  18. Effects of the Changiang river discharge on the change in ocean and atmosphere over the East Asian region

    Science.gov (United States)

    Kim, M. H.; Lim, Y. J.; Kang, H. S.; Kim, B. J.; Cho, C.

    2017-12-01

    This study investigates the effects of freshwater from the Changiang river basin over the East Asian region for summer season. To do this, we simulated global seasonal forecasting system (GloSea5) of KMA (Korea Meteorology Administration). GloSea5 consists of atmosphere, ocean, sea ice and land model. Also, it has river routing model (TRIP), which links between land and ocean using freshwater. It is very important component in long-term forecast because of be able to change the air-sea interaction. To improve more the freshwater performance over the East Asian region, we realistically modified the river mouth, direction and storage around Changiang river basin of TRIP in GloSea5. Here, the comparison study among the no freshwater forcing experiment to ocean model (TRIP-OFF), the operated original file based freshwater coupled experiment (TRIP-ON) and the improved one (TRIP-MODI) has been carried out and the results are evaluated against the reanalysis data. As a result, the amount of fresh water to the Yellow Sea increase in TRIP-ON experiment and it attributes to the improvement of bias and RMSE of local SST over the East Asia. The implementation of the realistic river related ancillary files (TRIP-MODI) improves the abnormal salinity distribution around the Changjiang river gate and its related SST reduces cold bias about 0.37˚C for July over the East Sea. Warm SST over this region is caused by barrier layer (BL). Freshwater flux and salinity changes can create a pronounced salinity-induced mixed layer (ML) above the top of the thermocline. The layer between the base of the ML and the top of the thermocline is called a barrier layer (BL), because it isolates the warm surface water from cold deep water. In addition, the improved fresh water forcing can lead to the change in the local volume transport from the Kuroshio to the Strait of Korea and Changed the transport and SST over the Straits of Korea have correlation 0.57 at 95% confidence level. For the

  19. Natural radioactivity of the atmosphere over the Indian land mass, inside deep mines, and over adjoining oceans

    International Nuclear Information System (INIS)

    Mishra, U.C.; Rangarajan, C.; Eapen, C.D.

    1980-01-01

    Measurements of the activities of short-lived radon and thoron daughters, long-lived RaD ( 210 Pb), and cosmic-ray produced 7 Be in the surface atmosphere of different regions of India and the neighboring seas are presented. The seasonal and geographical variations of the activities and the meteorological significance of these variations are also discussed. Over land, the natural activities due to radon and thoron daughters undergo an annual and diurnal cycle, which is an index of the variation in the vertical mixing of the surface atmosphere. Over the oceans the diurnal variations are not so pronounced as over the land. Detailed measurements at stationary positions over the Arabian Sea showed significant changes in radon which were in phase at all the positions. The levels of radon daughters in the Kolar Gold Field mines, the second deepest in the world, have been measured. Maximum values are about 10 pCi/liter, and the daughter products are in a state of high disequilibrium. RaD( 210 Pb) over the land undergoes a seasonal cycle similar to radon with winter maximums and summer minimums, indicating that it is mainly supported from ambient radon. Beryllium-7 undergoes a seasonal cycle similar to stratospheric fallout with reduced amplitude. This can be interpreted as being due to the presence of a seasonally dependent stratospheric 7 Be mixing with a constant level of 7 Be produced within the troposphere itself

  20. Planktivorous auklet Ptychoramphus aleuticus responses to ocean climate, 2005: Unusual atmospheric blocking?

    Science.gov (United States)

    Sydeman, William J.; Bradley, Russell W.; Warzybok, Pete; Abraham, Christine L.; Jahncke, Jaime; Hyrenbach, K. David; Kousky, Vernon; Hipfner, J. Mark; Ohman, Mark D.

    2006-10-01

    In spring-summer 2005, anomalous atmospheric-oceanographic coupling caused unprecedented reproductive failures and redistribution of a planktivorous marine bird in both central California (37°N) and southern British Columbia (50°N). At SE Farallon Island, CA, the birds abandoned the breeding colony en masse between 10-20 May, a unique behavioral response; for the first time in 35 years, reproductive success was zero. At Triangle Island, B.C., only 8% of the nesting pairs were successful, the worst year on record. Surveys of birds at sea revealed a peak in relative abundance south of Point Conception (34°N) in summer and fall, suggestive of emigration from the north. Prey (euphausiid crustacean) biomass in the Gulf of the Farallones was reduced, but remained high south of Point Conception. Change in predator and prey may be explained, in part, by unusual atmospheric blocking in the Gulf of Alaska in May, which caused the jet stream to shift southwards resulting in poor upwelling-favorable winds and anomalously warm SST. This study demonstrates the deleterious consequences of this climate event for a top marine predator in the central-northern California Current System.

  1. A SAR Observation and Numerical Study on Ocean Surface Imprints of Atmospheric Vortex Streets

    Directory of Open Access Journals (Sweden)

    William G. Pichel

    2008-05-01

    Full Text Available The sea surface imprints of Atmospheric Vortex Street (AVS off Aleutian Volcanic Islands, Alaska were observed in two RADARSAT-1 Synthetic Aperture Radar (SAR images separated by about 11 hours. In both images, three pairs of distinctive vortices shedding in the lee side of two volcanic mountains can be clearly seen. The length and width of the vortex street are about 60-70 km and 20 km, respectively. Although the AVS’s in the two SAR images have similar shapes, the structure of vortices within the AVS is highly asymmetrical. The sea surface wind speed is estimated from the SAR images with wind direction input from Navy NOGAPS model. In this paper we present a complete MM5 model simulation of the observed AVS. The surface wind simulated from the MM5 model is in good agreement with SAR-derived wind. The vortex shedding rate calculated from the model run is about 1 hour and 50 minutes. Other basic characteristics of the AVS including propagation speed of the vortex, Strouhal and Reynolds numbers favorable for AVS generation are also derived. The wind associated with AVS modifies the cloud structure in the marine atmospheric boundary layer. The AVS cloud pattern is also observed on a MODIS visible band image taken between the two RADARSAT SAR images. An ENVISAT advance SAR image taken 4 hours after the second RADARSAT SAR image shows that the AVS has almost vanished.

  2. Spontaneous abrupt climate change due to an atmospheric blocking-sea-ice-ocean feedback in an unforced climate model simulation.

    Science.gov (United States)

    Drijfhout, Sybren; Gleeson, Emily; Dijkstra, Henk A; Livina, Valerie

    2013-12-03

    Abrupt climate change is abundant in geological records, but climate models rarely have been able to simulate such events in response to realistic forcing. Here we report on a spontaneous abrupt cooling event, lasting for more than a century, with a temperature anomaly similar to that of the Little Ice Age. The event was simulated in the preindustrial control run of a high-resolution climate model, without imposing external perturbations. Initial cooling started with a period of enhanced atmospheric blocking over the eastern subpolar gyre. In response, a southward progression of the sea-ice margin occurred, and the sea-level pressure anomaly was locked to the sea-ice margin through thermal forcing. The cold-core high steered more cold air to the area, reinforcing the sea-ice concentration anomaly east of Greenland. The sea-ice surplus was carried southward by ocean currents around the tip of Greenland. South of 70 °N, sea ice already started melting and the associated freshwater anomaly was carried to the Labrador Sea, shutting off deep convection. There, surface waters were exposed longer to atmospheric cooling and sea surface temperature dropped, causing an even larger thermally forced high above the Labrador Sea. In consequence, east of Greenland, anomalous winds changed from north to south, terminating the event with similar abruptness to its onset. Our results imply that only climate models that possess sufficient resolution to correctly represent atmospheric blocking, in combination with a sensitive sea-ice model, are able to simulate this kind of abrupt climate change.

  3. Atmospheric Mercury Deposition to a Remote Islet in the Subtropical Northwest Pacific Ocean

    Science.gov (United States)

    Sheu, G.; Lin, N.

    2013-12-01

    Thirty-four weekly rainwater samples were collected in 2009 at Pengjiayu, a remote islet in the subtropical Northwest (NW) Pacific Ocean with an area of 1.14 km^2, to study the distribution of rainwater mercury (Hg) concentrations and associated wet deposition fluxes. This is the first study concerning wet Hg deposition to the subtropical NW Pacific Ocean downwind of the East Asian continent, which is the major source region for Hg emissions worldwide. Sample Hg concentrations ranged from 2.25 to 22.33 ng L^-1, with a volume-weighted mean (VWM) concentration of 8.85 ng L^-1. The annual wet Hg deposition flux was 10.18 μg m^-2, about 2.5 times the fluxes measured at sites on the Pacific coast of the USA, supporting the hypothesis that deposition is higher in the western than in the eastern Pacific. Seasonal VWM concentrations were 7.23, 11.58, 7.82, and 9.84 ng L^-1, whereas seasonal wet deposition fluxes were 2.14, 3.45, 2.38, and 2.21 μg m^-2, for spring, summer, fall and winter, respectively. Higher summer wet Hg deposition was a function of both higher rainwater Hg concentration and greater rainfall. The seasonal pattern of rainwater Hg concentrations was the opposite of the general seasonal pattern of the East Asian air pollutant export. Since there is no significant anthropogenic Hg emission source on the islet of Pengjiayu, the observed high summertime rainwater Hg concentration hints at the importance of Hg(0) oxidation and/or scavenging of upper-altitude reactive gaseous Hg (RGM) by deep convection. Direct anthropogenic RGM emissions from the East Asian continent may not contribute significantly to the rainwater Hg concentrations, but anthropogenic Hg(0) emissions could be transported to the upper troposphere or marine boundary layer where they can be oxidized to produce RGM, which will then be effectively scavenged by cloud water and rainwater.

  4. Open Architecture Standards and Information Systems (OASIS II ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Open Architecture Standards and Information Systems (OASIS II) - Developing Capacity, Sharing Knowledge and Good Principles Across eHealth in Africa. Health care across much of the African continent is hampered by meager resources and a growing burden of disease, with HIV/AIDS, tuberculosis (TB) and malaria ...

  5. Rwanda Health and Education Information Network (OASIS-RHEIN ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Rwanda Health and Education Information Network (OASIS-RHEIN). Partners in Health (PIH), an international nongovernmental organization, has demonstrated the effectiveness of its open source electronic medical record system (OpenMRS) in eight clinics in Rwanda. As a result, the Ministry of Health has decided to roll ...

  6. Surface roughness considerations for atmospheric correction of ocean color sensors. I - The Rayleigh-scattering component. II - Error in the retrieved water-leaving radiance

    Science.gov (United States)

    Gordon, Howard R.; Wang, Menghua

    1992-01-01

    The first step in the Coastal Zone Color Scanner (CZCS) atmospheric-correction algorithm is the computation of the Rayleigh-scattering (RS) contribution, L sub r, to the radiance leaving the top of the atmosphere over the ocean. In the present algorithm, L sub r is computed by assuming that the ocean surface is flat. Calculations of the radiance leaving an RS atmosphere overlying a rough Fresnel-reflecting ocean are presented to evaluate the radiance error caused by the flat-ocean assumption. Simulations are carried out to evaluate the error incurred when the CZCS-type algorithm is applied to a realistic ocean in which the surface is roughened by the wind. In situations where there is no direct sun glitter, it is concluded that the error induced by ignoring the Rayleigh-aerosol interaction is usually larger than that caused by ignoring the surface roughness. This suggests that, in refining algorithms for future sensors, more effort should be focused on dealing with the Rayleigh-aerosol interaction than on the roughness of the sea surface.

  7. The contribution of ocean-leaving DMS to the global atmospheric burdens of DMS, MSA, SO2, and NSS SO4=

    NARCIS (Netherlands)

    van Himbergen-Gondwe, P.M.; Krol, M.; Gieskes, W.W C; Klaassen, W.; de Baar, H.J.W.

    2003-01-01

    [1] The contribution of ocean-derived DMS to the atmospheric burdens of a variety of sulphur compounds (DMS, MSA, SO2, and nss SO4=) is quantified from season to season. Such quantification, especially for nss SO4= (the climate-relevant product of DMS oxidation), is essential for the quantification

  8. Ocean-atmosphere pollutant circulation processes: The Heligoland Bight ecosystem (PRISMA). 2. interim report (1991)

    International Nuclear Information System (INIS)

    1992-04-01

    The PRISMA BMFT project is an important stage on the way to a comprehensive knowledge of the impacts of pollutants on the North Sea/Heligoland Bight ecosystem. The overall project is dedicated to the development, verification and application of a complex shelf-sea model which provides qualitative and quantitative data about the causal interactions between the basic atmospheric conditions, the hydrodynamics and thermodynamics of the water, the chemical reactons in the air, in the water and the sediments, and the activity of organisms. The model comprises a compact set of formulae, process formulations, initial and marginal conditions and empirical parameters which serves to describe the origin, transport, reactions and final deposition of pollutants in the North Sea, helps to analyze and elucidate the present condition of the ecosystem and its spatial and temporal variability, and provides forecasts in accordance with the changing natural and anthropogenic environmental conditions. (orig.) [de

  9. Survey of polyfluorinated chemicals (PFCs) in the atmosphere over the northeast Atlantic Ocean

    Science.gov (United States)

    Shoeib, Mahiba; Vlahos, Penny; Harner, Tom; Peters, Andrew; Graustein, Margaret; Narayan, Julie

    2010-08-01

    High volume air sampling in Bermuda, Sable Island (Nova Scotia) and along a cruise track from the Gulf of Mexico to northeast coast of the USA, was carried out to assess air concentrations, particle-gas partitioning and transport of polyfluorinated chemicals (PFCs) in this region. Samples were collected in the summer of 2007. Targeted compounds included the neutral PFCs: fluorotelomer alcohols (FTOHs), perfluoroalkyl sulfonamides (FOSAs) and perfluoroalkyl sulfonamido ethanols (FOSEs). Among the FTOHs, 8:2 FTOH was dominant in all samples. Sum of the concentration of FTOHs (gas+particle phase) were higher in Bermuda (mean, 34 pg m -3) compared to Sable Island (mean, 16 pg m -3). In cruise samples, sum of FTOHs were highly variable (mean, 81 pg m -3) reflecting contributions from land-based sources in the northeast USA with concentrations reaching as high as 156 pg m -3. Among the FOSAs and FOSEs, MeFOSE was dominant in all samples. In Bermuda, levels of MeFOSE were exceptionally high (mean, 62 pg m -3), exceeding the FTOHs. Sable Island samples also exhibited the dominance of MeFOSE but at a lower concentration (mean, 15 pg m -3). MeFOSE air concentrations (pg m -3) in cruise samples ranged from 1.6 to 73 and were not linked to land-based sources. In fact high concentrations of MeFOSE observed in Bermuda were associated with air masses that originated over the Atlantic Ocean. The partitioning to particles for 8:2 FTOH, 10:2 FTOH, MeFOSE and EtFOSE ranged from as high as 15 to 42% for cruise samples to 0.9 to 14% in Bermuda. This study provides key information for validating and developing partitioning and transport models for the PFCs.

  10. Ocean Station Vessel

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean Station Vessels (OSV) or Weather Ships captured atmospheric conditions while being stationed continuously in a single location. While While most of the...

  11. Mediterranean Thermohaline Response to Large-Scale Winter Atmospheric Forcing in a High-Resolution Ocean Model Simulation

    Science.gov (United States)

    Cusinato, Eleonora; Zanchettin, Davide; Sannino, Gianmaria; Rubino, Angelo

    2018-04-01

    Large-scale circulation anomalies over the North Atlantic and Euro-Mediterranean regions described by dominant climate modes, such as the North Atlantic Oscillation (NAO), the East Atlantic pattern (EA), the East Atlantic/Western Russian (EAWR) and the Mediterranean Oscillation Index (MOI), significantly affect interannual-to-decadal climatic and hydroclimatic variability in the Euro-Mediterranean region. However, whereas previous studies assessed the impact of such climate modes on air-sea heat and freshwater fluxes in the Mediterranean Sea, the propagation of these atmospheric forcing signals from the surface toward the interior and the abyss of the Mediterranean Sea remains unexplored. Here, we use a high-resolution ocean model simulation covering the 1979-2013 period to investigate spatial patterns and time scales of the Mediterranean thermohaline response to winter forcing from NAO, EA, EAWR and MOI. We find that these modes significantly imprint on the thermohaline properties in key areas of the Mediterranean Sea through a variety of mechanisms. Typically, density anomalies induced by all modes remain confined in the upper 600 m depth and remain significant for up to 18-24 months. One of the clearest propagation signals refers to the EA in the Adriatic and northern Ionian seas: There, negative EA anomalies are associated to an extensive positive density response, with anomalies that sink to the bottom of the South Adriatic Pit within a 2-year time. Other strong responses are the thermally driven responses to the EA in the Gulf of Lions and to the EAWR in the Aegean Sea. MOI and EAWR forcing of thermohaline properties in the Eastern Mediterranean sub-basins seems to be determined by reinforcement processes linked to the persistency of these modes in multiannual anomalous states. Our study also suggests that NAO, EA, EAWR and MOI could critically interfere with internal, deep and abyssal ocean dynamics and variability in the Mediterranean Sea.

  12. A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their Interactions with the Larger-Scale Environment

    Science.gov (United States)

    Zuidema, Paquita; Torri, Giuseppe; Muller, Caroline; Chandra, Arunchandra

    2017-11-01

    Pools of air cooled by partial rain evaporation span up to several hundreds of kilometers in nature and typically last less than 1 day, ultimately losing their identity to the large-scale flow. These fundamentally differ in character from the radiatively-driven dry pools defining convective aggregation. Advancement in remote sensing and in computer capabilities has promoted exploration of how precipitation-induced cold pool processes modify the convective spectrum and life cycle. This contribution surveys current understanding of such cold pools over the tropical and subtropical oceans. In shallow convection with low rain rates, the cold pools moisten, preserving the near-surface equivalent potential temperature or increasing it if the surface moisture fluxes cannot ventilate beyond the new surface layer; both conditions indicate downdraft origin air from within the boundary layer. When rain rates exceed ˜ 2 mm h^{-1}, convective-scale downdrafts can bring down drier air of lower equivalent potential temperature from above the boundary layer. The resulting density currents facilitate the lifting of locally thermodynamically favorable air and can impose an arc-shaped mesoscale cloud organization. This organization allows clouds capable of reaching 4-5 km within otherwise dry environments. These are more commonly observed in the northern hemisphere trade wind regime, where the flow to the intertropical convergence zone is unimpeded by the equator. Their near-surface air properties share much with those shown from cold pools sampled in the equatorial Indian Ocean. Cold pools are most effective at influencing the mesoscale organization when the atmosphere is moist in the lower free troposphere and dry above, suggesting an optimal range of water vapor paths. Outstanding questions on the relationship between cold pools, their accompanying moisture distribution and cloud cover are detailed further. Near-surface water vapor rings are documented in one model inside but

  13. Effect of Modulation of ENSO by Decadal and Multidecadal Ocean-Atmospheric Oscillations on Continental US Streamflows

    Science.gov (United States)

    Singh, S.; Abebe, A.; Srivastava, P.; Chaubey, I.

    2017-12-01

    Evaluation of the influences of individual and coupled oceanic-atmospheric oscillations on streamflow at a regional scale in the United States is the focus of this study. The main climatic oscillations considered in this study are: El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and North Atlantic Oscillation (NAO). Unimpacted or minimally impacted by water management streamflow data from the Model Parameter Estimation Experiment (MOPEX) were used in this study. Two robust and novel non-parametric tests, namely, the rank based partial least square (PLS) and the Joint Rank Fit (JRFit) procedures were used to identify the individual and coupled effect of oscillations on streamflow across continental U.S. (CONUS), respectively. Moreover, the interactive effects of ENSO with decadal and multidecadal cycles were tested and quantified using the JRFit interaction test. The analysis of ENSO indicated higher streamflows during La Niña phase compared to the El Niño phase in Northwest, Northeast and the lower part of Ohio Valley while the opposite occurs for rest of the climatic regions in US. Two distinct climate regions (Northwest and Southeast) were identified from the PDO analysis where PDO negative phase results in increased streamflow than PDO positive phase. Consistent negative and positive correlated regions around the CONUS were identified for AMO and NAO, respectively. The interaction test of ENSO with decadal and multidecadal oscillations showed that El Niño is modulated by the negative phase of PDO and NAO, and the positive phase of AMO, respectively, in the Upper Midwest. However, La Niña is modulated by the positive phase of AMO and PDO in Ohio Valley and Northeast while in Southeast and the South it is modulated by AMO negative phase. Results of this study will assist water managers to understand the streamflow change patterns across the CONUS at decadal and multi-decadal time scales. The

  14. Ocean Uses: Hawaii (PROUA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Pacific Regional Ocean Uses Atlas (PROUA) Project is an innovative partnership between NOAA and the Bureau of Ocean Energy Management (BOEM) designed to...

  15. On the role of atmosphere-ocean interactions in the expected long-term changes of the Earth's ozone layer caused by greenhouse gases

    Science.gov (United States)

    Zadorozhny, Alexander; Dyominov, Igor

    It is well known that anthropogenic emissions of greenhouse gases into the atmosphere produce a global warming of the troposphere and a global cooling of the stratosphere. The expected stratospheric cooling essentially influences the ozone layer via increased polar stratospheric cloud formation and via temperature dependences of the gas phase reaction rates. One more mechanism of how greenhouse gases influences the ozone layer is enhanced water evaporation from the oceans into the atmosphere because of increasing temperatures of the ocean surface due to greenhouse effect. The subject of this paper is a study of the influence of anthropogenic pollution of the atmosphere by the greenhouse gases CO2, CH4, N2O and ozone-depleting chlorine and bromine compounds on the expected long-term changes of the ozone layer with taking into account an increase of water vapour content in the atmosphere due to greenhouse effect. The study based on 2-D zonally averaged interactive dynamical radiative-photochemical model of the troposphere and stratosphere. The model allows to self-consistently calculating diabatic circulation, temperature, gaseous composition of the troposphere and stratosphere at latitudes from the South to North Poles, as well as distribution of sulphate aerosol particles and polar stratospheric clouds of two types. It was supposed in the model that an increase of the ocean surface temperature caused by greenhouse effect is similar to calculated increase of atmospheric surface temperature. Evaporation rate from the ocean surface was computed in dependence of latitude. The model time-dependent runs were made for the period from 1975 to 2100 using two IPCC scenarios depicting maximum and average expected increases of greenhouse gases in the atmosphere. The model calculations show that anthropogenic increasing of water vapour abundance in the atmosphere due to heating of the ocean surface caused by greenhouse effect gives a sensible contribution to the expected ozone

  16. Assessment of the possible future climatic impact of carbon dioxide increases based on a coupled one-dimensional atmospheric-oceanic model

    International Nuclear Information System (INIS)

    Hunt, B.G.; Wells, N.C.

    1979-01-01

    A radiative-convective equilibrium model of the atmosphere has been coupled with a mixed layer model of the ocean to investigate the response of this one-dimensional system to increasing carbon dioxide amounts in the atmosphere. For global mean conditions a surface temperature rise of about 2 0 K was obtained for a doubling of the carbon dioxide amount, in reasonable agreement with the commonly accepted results of Manabe and Wetherald. This temperature rise was essentially invariant with season and indicates that including a shallow (300 m) ocean slab in this problem does not basically alter previous assessments. While the mixed layer depth of the ocean was only very slightly changed by the temperature increase, which extended throughout the depth of the mixed layer, the impact of this increase on the overall behavior of the ocean warrants further study. A calculation was also made of the temporal variation of the sea surface temperature for three possible carbon dioxide growth rates starting from an initial carbon dioxide content of 300 ppm. This indicated that the thermal inertia of the slab ocean provides a time lag of 8 years in the sea surface temperature response compared to a land situation. This is not considered to be of great significance as regards the likely future climatic impact of carbon dioxide increase

  17. CH4 fluxes across the seafloor at three district gas hydrate fields: Impacts on ocean and atmosphere chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kastner, M.; Bartlett, D.; MacDonald, I.; Solomon, E.

    2005-07-01

    The role of methane hydrate in the global methane budget is poorly documented because relatively little is known about the transport of methane through the seafloor into the ocean and atmosphere, and the extent of en route water-column methanotrophy. Pore fluids and water column samples within and adjacent to methane plumes were analyzed for methane, dissolved inorganic C (DIC), sulfide/sulfate, alkalinity, and major element concentrations, and for delta{sup 13}C-CH4 and DIC, at three distinct gas hydrate environments. The three environments are: Bush Hill (BH) in the northern Gulf of Mexico (GOM), Eel River (ER) offshore Northern California, and North and South Hydrate Ridges (HR), Cascadia, Oregon margin. The methane source at these sites ranges from mostly thermogenic at GOM to primarily biogenic at HR. At these three distinct gas hydrate environments, at all the sites a significant enrichment in {sup 13}C-CH4 along isopycnals away from the methane plumes is observed, indicating extensive aerobic bacterial methane oxidation in the water column, and correspondingly of oxygen consumption. This is principally pronounced in the mostly biogenic methane setting. The delta{sup 13}C-CH4 values range from approx. 12 to -67 , PDB, at the Hydrate Ridges, from approx. 34 to -52 at Eel River, and from approx. 41 to -67 at Bush Hill. The large variation in methane C isotope ranges between the sites suggests that major differences exist in both the rates of aerobic methane oxidation and system openness at the studied locations. Methane fluxes across the sediment/seawater interface were measured, with a flux meter, MOSQUITO (Multiple Orifice Sampler and Quantitative Injection Tracer Observers) only at BH (Solomon et al., 2005). Water column methane concentrations are on average lower at HR than at ER and GOM. Preliminary estimates suggests that aerobic oxidation is nearly complete, consumes most to all of the water column methane at HR, but at the GOM only approx. 80% to a

  18. The Outcome and Assessment Information Set (OASIS): A Review of Validity and Reliability

    Science.gov (United States)

    O’CONNOR, MELISSA; DAVITT, JOAN K.

    2015-01-01

    The Outcome and Assessment Information Set (OASIS) is the patient-specific, standardized assessment used in Medicare home health care to plan care, determine reimbursement, and measure quality. Since its inception in 1999, there has been debate over the reliability and validity of the OASIS as a research tool and outcome measure. A systematic literature review of English-language articles identified 12 studies published in the last 10 years examining the validity and reliability of the OASIS. Empirical findings indicate the validity and reliability of the OASIS range from low to moderate but vary depending on the item studied. Limitations in the existing research include: nonrepresentative samples; inconsistencies in methods used, items tested, measurement, and statistical procedures; and the changes to the OASIS itself over time. The inconsistencies suggest that these results are tentative at best; additional research is needed to confirm the value of the OASIS for measuring patient outcomes, research, and quality improvement. PMID:23216513

  19. Geologic evaluation of the Oasis Valley basin, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Fridrich, C.J.; Minor, S.A.; and Mankinen, E.A.

    2000-01-13

    This report documents the results of a geologic study of the area between the underground-nuclear-explosion testing areas on Pahute Mesa, in the northwesternmost part of the Nevada Test Site, and the springs in Oasis Valley, to the west of the Test Site. The new field data described in this report are also presented in a geologic map that is a companion product(Fridrich and others, 1999) and that covers nine 7.5-minute quadrangles centered on Thirsty Canyon SW, the quadrangle in which most of the Oasis Valley springs are located. At the beginning of this study, published detailed maps were available for 3 of the 9 quadrangles of the study area: namely Thirsty Canyon (O'Connor and others, 1966); Beatty (Maldonado and Hausback, 1990); and Thirsty Canyon SE (Lipman and others, 1966). Maps of the last two of these quadrangles, however, required extensive updating owing to recent advances in understanding of the regional structure and stratigraphy. The new map data are integrated in this re port with new geophysical data for the Oasis Valley area, include gravity, aeromagnetic, and paleomagnetic data (Grauch and others, 1997; written comm., 1999; Mankinen and others, 1999; Hildenbrand and others, 1999; Hudson and others, 1994; Hudson, unpub. data).

  20. Observations of atmospheric lead-210 over the Atlantic Ocean and Antarctica during the FINNARP-1999/2999 Expedition

    Energy Technology Data Exchange (ETDEWEB)

    Paatero, J.; Virkkula, A.; Hillamo, R. [Finnish Meteorological Inst., Helsinki (Finland); Koponen, I. [Univ. of Helsinki, Dept. of Physics, Helsinki (Finland)

    2002-04-01

    Physical and chemical properties of the atmosphere were measured in November-December 1999 onboard the Russian research vessel Akademik Fedorov over the Atlantic Ocean between the English Channel and the coast of Antarctica. After the cruise the measurements were continued in January 2000 at the Finnish research station Aboa (73 deg. 03'S, 13 deg. 25'W, 470 m above sea level) in Dronning Maud Land, Antarctica. The location of the station is about 170 km inland from the coast of Weddell Sea. The study is part of the Finnish Antarctic Research Programme (FINNARP) financed by the Academy of Finland. The observed {sup 210}Pb activity concentrations in the air varied between 24 and 790 {mu}Bq/m{sup 3} during the cruise between the English Channel and Cape town. The highest values were recorded close (<300-400 km) to the West-African coast between Senegal and Liberia. This coincides with the observations of highest aerosol optical thickness and light scattering coefficients. The latter observation can be attributed to two factors, biomass burning in Western Africa or resuspension of soil in the Sahara desert. Because anthropogenic activities have a negligible effect to the amount of lead-210 in the air, the resuspension in the Sahara desert is a more plausible explanation. Between Cape Town and the coast of Antarctica the observed {sup 210}Pb activity concentrations varied between <10 and 51 {mu}Bq/m{sup 3}. At the research station Aboa the observed values varied between <10 and 37 {mu}Bq/m{sup 3}. Between 6 and 11 January 2000 the air masses at Aboa originated from central regions of Antarctica according to the trajectory calculations made with the NORA Hysplit model. The concentrations were below detection limit between 11 and 14 January. These samples were connected to the air masses originating from the South Atlantic Ocean. Between 14 and 20 January air masses came to Aboa mainly from easterly direction from coastal and inland regions of the Antarctica

  1. On the Revealing Firsthand Probing of Ocean-Ice-Atmosphere Interactions off Sabrina Coast During NBP1402

    Science.gov (United States)

    Huber, B. A.; Orsi, A. H.; Zielinski, N. J.; Durkin, W. J., IV; Clark, P.; Wiederwohl, C. L.; Rosenberg, M. A.; Gwyther, D.; Greenbaum, J. S.; Lavoie, C.; Shevenell, A.; Leventer, A.; Blankenship, D. D.; Gulick, S. P. S.; Domack, E. W.

    2014-12-01

    Diverse interactions of winds, currents and ice around Antarctica dictate how, where and when the world's densest waters form and massive floating ice shelves and glaciers melt, as well as control sea surface gas exchange and primary productivity. Compelled by recent rate estimates of East Antarctic Ice Sheet mass loss, we contrast the paths and mixing histories of oceanic waters reaching the continental ice edge off the Sabrina and Adelie coasts relying on the unique set of synoptic shipboard measurements from NBP1402 (swath bathymetry, ADCP, underway CTD). Analysis of historical hydrography and sea ice concentration fields within the Mertz Polynya indicates the apparent effect of evolving ocean-ice-atmosphere interactions on the characteristics of local Shelf Water (SW) sources to current outflow of newly formed Antarctic Bottom Water (AABW). A polynya dominated water mass structure similar to that observed off the Adelie Coast before the removal of the Mertz Ice Tongue was expected to the west of the Dalton Ice Tongue (DIT). However, we found no evidence of dense SW off Sabrina Coast, which may lessen the region's preconceived influence to global meridional overturning. Present sea ice production within the eastern Dalton Polynya is overshadowed by freshwater input to relatively stable interior upper waters. The Antarctic Coastal Current (ACoC) picks up distinct meltwater contributions along the DIT western flank and in front of the Moscow University Ice Shelf (MUIS) and Totten Glacier (TG). Unlike over other highly influential margins to global sea level rise, there is no evidence of local cross-shelf inflow and mixing of warm Circumpolar Deep Water. Relatively cold thermocline waters from the continental slope enter the eastern trough off Sabrina Coast, and they are swiftly steered poleward by complex underlying topography. Meltwater export from beneath the MUIS and TG is observed at newly discovered trenches that effectively constrain sub-cavity inflow to low

  2. Long-Term Observations of Atmospheric CO2, O3 and BrO over the Transitioning Arctic Ocean Pack-ice: The O-Buoy Chemical Network

    Science.gov (United States)

    Matrai, P.

    2016-02-01

    Autonomous, sea ice-tethered O-Buoys have been deployed (2009-2016) across the Arctic sea ice for long-term atmospheric measurements (http://www.o-buoy.org). O-Buoys (15) provide in-situ concentrations of three sentinel atmospheric chemicals, ozone, CO2 and BrO, as well as meteorological parameters and imagery, over the frozen ocean. O-Buoys were designed to transmit daily data over a period of 2 years while deployed in sea ice, as part of automated ice-drifting stations that include snow/ice measurement systems (e.g. Ice Mass Balance buoys) and oceanographic measurements (e.g. Ice Tethered Profilers). Seasonal changes in Arctic atmospheric chemistry are influenced by changes in the characteristics and presence of the sea ice vs. open water as well as air mass trajectories, especially during the winter-spring and summer-fall transitions when sea ice is melting and freezing, respectively. The O-Buoy Chemical Network provides the unique opportunity to observe these transition periods in real-time with high temporal resolution, and to compare them with those collected on land-based monitoring stations located. Due to the logistical challenges of measurements over the Arctic Ocean region, most long term, in-situ observations of atmospheric chemistry have been made at coastal or island sites around the periphery of the Arctic Ocean, leaving large spatial and temporal gaps that O-Buoys overcome. Advances in floatation, communications, power management, and sensor hardware have been made to overcome the challenges of diminished Arctic sea ice. O-Buoy data provide insights into enhanced seasonal, interannual and spatial variability in atmospheric composition, atmospheric boundary layer control on the amount of halogen activation, enhancement of the atmospheric CO2 signal over the more variable and porous pack ice, and to develop an integrated picture of the coupled ocean/ice/atmosphere system. As part of the Arctic Observing Network, we provide data to the community (www.aoncadis.org).

  3. Submesoscale features and their interaction with fronts and internal tides in a high-resolution coupled atmosphere-ocean-wave model of the Bay of Bengal

    Science.gov (United States)

    Jensen, Tommy G.; Shulman, Igor; Wijesekera, Hemantha W.; Anderson, Stephanie; Ladner, Sherwin

    2018-03-01

    Large freshwater fluxes into the Bay of Bengal by rainfall and river discharges result in strong salinity fronts in the bay. In this study, a high-resolution coupled atmosphere-ocean-wave model with comprehensive physics is used to model the weather, ocean circulation, and wave field in the Bay of Bengal. Our objective is to explore the submesoscale activity that occurs in a realistic coupled model that resolves mesoscales and allows part of the submesoscale field. Horizontal resolution in the atmosphere varies from 2 to 6 km and is 13 km for surface waves, while the ocean model is submesoscale permitting with resolutions as high as 1.5 km and a vertical resolution of 0.5 m in the upper 10 m. In this paper, three different cases of oceanic submesoscale features are discussed. In the first case, heavy rainfall and intense downdrafts produced by atmospheric convection are found to force submesoscale currents, temperature, and salinity anomalies in the oceanic mixed layer and impact the mesoscale flow. In a second case, strong solitary-like waves are generated by semidiurnal tides in the Andaman Sea and interact with mesoscale flows and fronts and affect submesoscale features generated along fronts. A third source of submesoscale variability is found further north in the Bay of Bengal where river outflows help maintain strong salinity gradients throughout the year. For that case, a comparison with satellite observations of sea surface height anomalies, sea surface temperature, and chlorophyll shows that the model captures the observed mesoscale eddy features of the flow field, but in addition, submesoscale upwelling and downwelling patterns associated with ageostrophic secondary circulations along density fronts are also captured by the model.

  4. Implementation of the vortex force formalism in the coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system for inner shelf and surf zone applications

    Science.gov (United States)

    Kumar, Nirnimesh; Voulgaris, George; Warner, John C.; Olabarrieta, Maitane

    2012-01-01

    The coupled ocean-atmosphere-wave-sediment transport modeling system (COAWST) enables simulations that integrate oceanic, atmospheric, wave and morphological processes in the coastal ocean. Within the modeling system, the three-dimensional ocean circulation module (ROMS) is coupled with the wave generation and propagation model (SWAN) to allow full integration of the effect of waves on circulation and vice versa. The existing wave-current coupling component utilizes a depth dependent radiation stress approach. In here we present a new approach that uses the vortex force formalism. The formulation adopted and the various parameterizations used in the model as well as their numerical implementation are presented in detail. The performance of the new system is examined through the presentation of four test cases. These include obliquely incident waves on a synthetic planar beach and a natural barred beach (DUCK' 94); normal incident waves on a nearshore barred morphology with rip channels; and wave-induced mean flows outside the surf zone at the Martha's Vineyard Coastal Observatory (MVCO).

  5. Quantifying the Fluxes of Atmospherically Derived Trace Elements in the Arctic Ocean/Ice System using 7Be

    Science.gov (United States)

    Landing, W. M.; Kadko, D. C.; Shelley, R.; Galfond, B.

    2016-02-01

    Aerosol deposition is an important pathway for delivering biologically-essential and anthropogenically-derived trace elements to the Arctic Ocean. Limited field study in the harsh Arctic environment has forced a reliance on poorly constrained models for the atmospheric deposition of trace elements. Here we use the cosmic ray produced radioisotope 7Be to link aerosol concentrations to flux to the Arctic water/ice system. Seawater, ice, snow, melt pond, and aerosol samples were collected during late summer 2011 as part of the RV Polarstern ARK-XXVI/3 campaign. The average 7Be aerosol loading was 0.018 dpm m-3 and we determined an average 7Be flux of 125 dpm m-2 d-1, consistent with results from previous studies in the region. None of the lithogenic aerosol elements showed any significant enrichment above crustal composition, while the pollution-type elements showed varying degrees of enrichment relative to crustal values. In addition to our own measurements, we use two years of continuous aerosol 7Be and trace element data from the Alert (Canada) monitoring site to generate seasonal and annual estimates for the fluxes of 7Be and trace elements to the Arctic water/ice system. Fluxes of 7Be are 30% higher in Winter (Nov-May) than in Summer (Jun-Oct) due to the strong seasonality in aerosol 7Be concentrations. Fluxes of lithogenic elements (Al, Mn, Fe) are 2-3 times higher in Summer, possibly due to local dust sources on Ellesmere Island. Fluxes of V and Pb are strongly correlated and are 2-3 times higher in Winter, while fluxes of Ni, Cu, and Zn are relatively uniform for both seasons.

  6. A conceptual prediction model for seasonal drought processes using atmospheric and oceanic standardized anomalies: application to regional drought processes in China

    Science.gov (United States)

    Liu, Zhenchen; Lu, Guihua; He, Hai; Wu, Zhiyong; He, Jian

    2018-01-01

    Reliable drought prediction is fundamental for water resource managers to develop and implement drought mitigation measures. Considering that drought development is closely related to the spatial-temporal evolution of large-scale circulation patterns, we developed a conceptual prediction model of seasonal drought processes based on atmospheric and oceanic standardized anomalies (SAs). Empirical orthogonal function (EOF) analysis is first applied to drought-related SAs at 200 and 500 hPa geopotential height (HGT) and sea surface temperature (SST). Subsequently, SA-based predictors are built based on the spatial pattern of the first EOF modes. This drought prediction model is essentially the synchronous statistical relationship between 90-day-accumulated atmospheric-oceanic SA-based predictors and SPI3 (3-month standardized precipitation index), calibrated using a simple stepwise regression method. Predictor computation is based on forecast atmospheric-oceanic products retrieved from the NCEP Climate Forecast System Version 2 (CFSv2), indicating the lead time of the model depends on that of CFSv2. The model can make seamless drought predictions for operational use after a year-to-year calibration. Model application to four recent severe regional drought processes in China indicates its good performance in predicting seasonal drought development, despite its weakness in predicting drought severity. Overall, the model can be a worthy reference for seasonal water resource management in China.

  7. Multi-factor evaluation indicator method for the risk assessment of atmospheric and oceanic hazard group due to the attack of tropical cyclones

    Science.gov (United States)

    Qi, Peng; Du, Mei

    2018-06-01

    China's southeast coastal areas frequently suffer from storm surge due to the attack of tropical cyclones (TCs) every year. Hazards induced by TCs are complex, such as strong wind, huge waves, storm surge, heavy rain, floods, and so on. The atmospheric and oceanic hazards cause serious disasters and substantial economic losses. This paper, from the perspective of hazard group, sets up a multi-factor evaluation method for the risk assessment of TC hazards using historical extreme data of concerned atmospheric and oceanic elements. Based on the natural hazard dynamic process, the multi-factor indicator system is composed of nine natural hazard factors representing intensity and frequency, respectively. Contributing to the indicator system, in order of importance, are maximum wind speed by TCs, attack frequency of TCs, maximum surge height, maximum wave height, frequency of gusts ≥ Scale 8, rainstorm intensity, maximum tidal range, rainstorm frequency, then sea-level rising rate. The first four factors are the most important, whose weights exceed 10% in the indicator system. With normalization processing, all the single-hazard factors are superposed by multiplying their weights to generate a superposed TC hazard. The multi-factor evaluation indicator method was applied to the risk assessment of typhoon-induced atmospheric and oceanic hazard group in typhoon-prone southeast coastal cities of China.

  8. Oceanic and atmospheric patterns during spawning periods prior to extreme catches of the Brazilian sardine (Sardinella brasiliensis in the southwest Atlantic

    Directory of Open Access Journals (Sweden)

    Helena Cachanhuk Soares

    2011-07-01

    Full Text Available Relative maxima and minima of landings of Brazilian sardine captured in the Southeast Brazil Bight (SBB were compared with oceanic and atmospheric composites relative to the spawning period in December and January, prior to these landings. Atmospheric and oceanic variables such as wind stress, Ekman transport, mixing index, sea surface temperature (SST, precipitation, outgoing long wave radiation and geopotential height were analyzed, revealing distinct climatological patterns in the SBB for these extreme catches that have not been described before. The system could be characterized by cooler SST composite anomaly (SSTA along the SBB as a response to increased cloud cover and reduced incidence of short-wave radiation, predominating one year before the Brazilian sardine catch maxima. This system can take on a different configuration in which positive SSTA condition in the SBB is associated with a less intense South Atlantic Convergence Zone displaced southwards one year before the period of minimum catch. Our results indicate that the spatial structure of the spawning habitat is influenced by specific ocean-atmosphere interactions rather than simply resulting from the choice of a stable environment. This climatic constraint strongly affects the interannual variability of the Brazilian sardine production.

  9. Extension of SCIATRAN by coupling atmospheric and oceanic radiative transfer: First results of comparisons for in-situ and satellite data

    Science.gov (United States)

    Blum, Mirjam; Rozanov, Vladimir; Bracher, Astrid; Burrows, John P.

    The radiative transfer model SCIATRAN [V. V. Rozanov et al., 2002; A. Rozanov et al., 2005, 2008] has been developed to model atmospheric radiative transfer. This model is mainly applied to improve the analysis of high spectrally resolved satellite data as, for instance, data of the instrument SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHar-tographY) onboard the ENVISAT satellite. Within the present study, SCIATRAN has been extended by taking radiative processes as well as at the atmosphere-water interface as within the water into account, which were caused by water itself and its constituents. Comparisons of this extended version of SCIATRAN for in-situ data and for MERIS satellite information yield first results, which will be shown. It is expected that the new version of SCIATRAN, including the coupling of atmospheric and oceanic radiative transfer, will widen the use of high spectrally resolved data in the form of achieving new findings, such as information about ocean biooptics and biogeochemistry like, for example, biomass of different phytoplankton groups or CDOM fluorescence. In addition, it is awaited that the new version improves the retrieval of atmospheric trace gases above oceanic waters. References: 1. V. V. Rozanov, M. Buchwitz, K.-U. Eichmann, R. de Beek, and J. P. Burrows. Sciatran -a new radiative transfer model for geophysical applications in the 240-2400nm spectral region: the pseudo-spherical version. Adv. in Space Res. 29, 1831-1835 (2002) 2. A. Rozanov, V. V. Rozanov, M. Buchwitz, A. Kokhanovsky, and J. P. Burrows. SCIA-TRAN 2.0 -A new radiative tranfer model for geophysical applications in the 175-2400nm spectral region. Adv. in Space Res. 36, 1015-1019 (2005) 3. A. Rozanov. SCIATRAN 2.X: Radiative transfer model and retrieval software package. URL = http://www.iup.physik.uni-bremen.de/sciatran (2008)

  10. 1.5 My benthic foraminiferal B/Ca record of carbonate chemistry in the deep Atlantic: Implications for ocean alkalinity and atmospheric CO2

    Science.gov (United States)

    Rosenthal, Y.; Sosdian, S. M.; Toggweiler, J. R.

    2017-12-01

    Most hypotheses to explain glacial-interglacial changes in atmospheric CO2 invoke shifts in ocean alkalinity explain roughly half the reduction in glacial CO2 via CaCO3 compensatory mechanism. It follows that changes in CaCO3 burial occur in response to an increase in deep ocean respired carbon content. To date our understanding of this process comes from benthic carbon isotope and %CaCO3 records. However, to understand the nature of the ocean's buffering capacity and its role in modulating pCO2, orbitally resolved reconstructions of the deep ocean carbonate system parameters are necessary. Here we present a 1.5 Myr orbitally resolved deep ocean calcite saturation record (ΔCO32-) derived from benthic foraminiferal B/Ca ratios in the North Atlantic. Glacial B/Ca values decline across the mid-Pleistocene transition (MPT) suggesting increased sequestration of carbon in the deep Atlantic. The magnitude, timing, and structure of deep Atlantic Ocean ΔCO32- and %CaCO3 cycles contrast with the small amplitude, anti-phased swings in IndoPacific ΔCO32- and %CaCO3 during the mid-to-late Pleistocene. Increasing corrosivity of the deep Atlantic causes the locus of CaCO3 burial to shift into the equatorial Pacific where the flux of CaCO3 to the seafloor is high enough to establish and maintain a new "hot spot". We propose that the CO32- in the deep IndoPacific rises in response to the same mechanism that keeps the CO32- in the deep Atlantic low and the atmospheric CO2 low. The increase in interglacial atmospheric pCO2 levels following the Mid-Brunhes event ( 400ka) are associated with increased G/IG ΔCO3 amplitude, expressed by a decrease in the glacial ΔCO32- values. We propose the low persistent ΔCO32- levels at Marine Isotope Stage (MIS) 12 set the stage for the high pCO2 levels at MIS 11 via an increase in whole ocean alkalinity followed by enhanced CaCO3 preservation. Based on this, we suggest that the development of classic (`anticorrelated') CaCO3 patterns was

  11. Earth 2075 (CO2) - can Ocean-Amplified Carbon Capture (oacc) Impart Atmospheric CO2-SINKING Ability to CCS Fossil Energy?

    Science.gov (United States)

    Fry, R.; Routh, M.; Chaudhuri, S.; Fry, S.; Ison, M.; Hughes, S.; Komor, C.; Klabunde, K.; Sethi, V.; Collins, D.; Polkinghorn, W.; Wroobel, B.; Hughes, J.; Gower, G.; Shkolnik, J.

    2017-12-01

    Previous attempts to capture atmospheric CO2 by algal blooming were stalled by ocean viruses, zooplankton feeding, and/or bacterial decomposition of surface blooms, re-releasing captured CO2 instead of exporting it to seafloor. CCS fossil energy coupling could bypass algal bloom limits—enabling capture of 10 GtC/yr atmospheric CO2 by selective emiliania huxleyi (EHUX) blooming in mid-latitude open oceans, far from coastal waters and polar seas. This could enable a 500 GtC drawdown, 350 ppm restoration by 2050, 280 ppm CO2 by 2075, and ocean pH 8.2. White EHUX blooms could also reflect sunlight back into outer space and seed extra ocean cloud cover, via DMS release, to raise albedo 1.8%—restoring preindustrial temperature (ΔT = 0°C) by 2030. Open oceans would avoid post-bloom anoxia, exclusively a coastal water phenomenon. The EHUX calcification reaction initially sources CO2, but net sinking prevails in follow-up equilibration reactions. Heavier-than-water EHUX sink captured CO2 to the sea floor before surface decomposition occurs. Seeding EHUX high on their nonlinear growth curve could accelerate short-cycle secondary open-ocean blooming—overwhelming mid-latitude viruses, zooplankton, and competition from other algae. Mid-latitude "ocean deserts" exhibit low viral, zooplankton, and bacterial counts. Thermocline prevents nutrient upwelling that would otherwise promote competing algae. Adding nitrogen nutrient would foster exclusive EHUX blooming. Elevated EHUX seed levels could arise from sealed, pH-buffered, floating, seed-production bioreactors infused with 10% CO2 from carbon feedstock supplied by inland CCS fossil power plants capturing 90% of emissions as liquid CO2. Deep-water SPAR platforms extract natural gas from beneath the sea floor. On-platform Haber and pH processing could convert extracted CH4 to buffered NH4+ nutrient, enabling ≥0.7 GtC/yr of bioreactor seed production and 10 GtC/yr of amplified secondary open-ocean CO2 capture—making CCS

  12. Hurricane Matthew (2016) and its Storm Surge Inundation under Global Warming Scenarios: Application of an Interactively Coupled Atmosphere-Ocean Model

    Science.gov (United States)

    Jisan, M. A.; Bao, S.; Pietrafesa, L.; Pullen, J.

    2017-12-01

    An interactively coupled atmosphere-ocean model was used to investigate the impacts of future ocean warming, both at the surface and the layers below, on the track and intensity of a hurricane and its associated storm surge and inundation. The category-5 hurricane Matthew (2016), which made landfall on the South Carolina coast of the United States, was used for the case study. Future ocean temperature changes and sea level rise (SLR) were estimated based on the projection of Inter-Governmental Panel on Climate Change (IPCC)'s Representative Concentration Pathway scenarios RCP 2.6 and RCP 8.5. After being validated with the present-day observational data, the model was applied to simulate the changes in track, intensity, storm surge and inundation that Hurricane Matthew would cause under future climate change scenarios. It was found that a significant increase in hurricane intensity, storm surge water level, and inundation area for Hurricane Matthew under future ocean warming and SLR scenarios. For example, under the RCP 8.5 scenario, the maximum wind speed would increase by 17 knots (14.2%), the minimum sea level pressure would decrease by 26 hPa (2.85%), and the inundated area would increase by 401 km2 (123%). By including the effect of SLR for the middle-21st-century scenario, the inundated area will further increase by up to 49.6%. The increase in the hurricane intensity and the inundated area was also found for the RCP 2.6 scenario. The response of sea surface temperature was analyzed to investigate the change in intensity. A comparison was made between the impacts when only the sea surface warming is considered versus when both the sea surface and the underneath layers are considered. These results showed that even without the effect of SLR, the storm surge level and the inundated area would be higher due to the increased hurricane intensity under the influence of the future warmer ocean temperature. The coupled effect of ocean warming and SLR would cause the

  13. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from USCGC BURTON ISLAND, USCGC GLACIER and USCGC NORTHWIND in the Arctic Ocean from 1971-07-30 to 1977-08-05 (NODC Accession 7800474)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity, temperature, depth (STD) and other data was collected using the United States Coast Guard (USCG) ships BURTON ISLAND, GLACIER and NORTH WIND by the US...

  14. Physical, meteorological, and other data from FIXED PLATFORMS from the TOGA Area - Pacific (30 N to 30 S) as part of the Tropical Ocean Global Atmosphere (TOGA) project from 01 January 1988 to 31 December 1988 (NODC Accession 8900241)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, meteorological, and other data were collected from FIXED PLATFORMS in the TOGA Area - Pacific (30 N to 30 S) from 01 January 1988 to 31 December 1988. Data...

  15. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from SURVEYOR in the North Pacific Ocean, Bering Sea and NE Pacific from 1995-09-10 to 1995-09-19 (NODC Accession 9600139)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hydrophysical, hydrochemical, and other data were collected from the SURVEYOR from September 10, 1995 to September 19, 1995. Data were submitted by Mr. David Kachel...

  16. Underway pressure, temperature, and salinity data from the MOANA WAVE from the Pacific warm pool in support of the Coupled Ocean-Atmosphere Response Experiment (COARE) from 02 February 1993 to 21 February 1993 (NODC Accession 9600090)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, temperature, and salinity data were collected while underway from the MOANA WAVE from the Pacific warm pool. Data were collected in support of the Coupled...

  17. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from ENDEAVOR, OCEANUS and other platforms in the NW Atlantic and North Atlantic Ocean from 1991-06-09 to 1996-04-19 (NODC Accession 9600125)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hydrochemical, hydrophysical, and other data were collected from NOAA Ship OREGON II, ENDEAVOR, OCEANUS, NOAA Ship CHAPMAN, SEWARD JOHNSON, NOAA Ship DELAWARE II,...

  18. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from ATLANTIS II in the NW Atlantic and South Atlantic Ocean from 1980-08-06 to 1980-09-04 (NODC Accession 9500041)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth, temperature and other nutrient bottle data were collected in NW Atlantic (limit-40 W) from ship ATLANTIS II cruise 107 Leg 10 between August 6, 1980...

  19. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from SAMUDERA and TYRO in the SW Pacific and South Pacific Ocean from 1984-08-01 to 1985-02-21 (NODC Accession 9300108)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NANSEN data collected during the cruises by the RV SAMUDERA and RV TYRO within theme 3 of the SNELLIUS II expedition, conducted by the Netherlands Institute for Sea...

  20. Surface water and atmospheric CO2 and N2O data set in the world-wide ocean from multiple cruises from 1977-11-07 to 1990-04-16 (NODC Accession 0000072)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and chemical data were collected using bottle and gas chromatograph casts from NOAA Ship Malcolm Baldrige and other platforms in the Atlantic and Pacific...

  1. Monitoring network of atmospheric Radon-222 concentration in East Asia and backward trajectory analysis of Radon-222 concentration trend at a small solitary island on pacific ocean

    International Nuclear Information System (INIS)

    Ohkura, Takehisa; Yamazawa, Hiromi; Moriizumi, Jun; Hirao, Shigekazu; Iida, Takao; Guo Qiuju; Tohjima, Yasunori

    2009-01-01

    A monitoring network of atmospheric 222 Rn concentration as a tracer for long-range transport in East Asia was established. Atmospheric 222 Rn concentration at Beijing, which is located on China Continent was 10-20 Bq m -3 , at Nagoya, which is located on edge of terrestrial area was 3-10 Bq m -3 and at Hachijo-jima and Hateruma-jima, which are solitary islands in Pacific Ocean was 0.5-3 Bq m -3 , respectively. The atmospheric 222 Rn concentration variations were different from sites. The 222 Rn concentration was the lowest in the summer and the highest in the winter except Nagoya where the highest was observed in the autumn and the lowest in the spring. Diurnal variations were measured at Beijing and Nagoya. In contrast, diurnal variations were not measured but several-day-cycle variations were measured at Hachijo-jima and Hateruma-jima. It was pointed out by this study that the several-day-cycle variations at Hachijo-jima were dependent on synoptic-scale atmospheric disturbance. 222 Rn concentration increased rapidly after a cold front passed through Hachijo-jima. Backward trajectory analysis of the relationship between atmospheric 222 Rn concentrations at Hachijo-jima and transport pathway of air mass indicates that air mass transported from China and Siberia has high concentration 222 Rn and air mass transported from Pacific Ocean has low concentration 222 Rn. In winter, atmospheric 222 Rn concentrations at Hachijo-jima is dependent on vertical transport pathway rather than horizontal transport pathway. (author)

  2. Windblown sediment transport and loss in a desert–oasis ecotone in the Tarim Basin

    Science.gov (United States)

    The Tarim Basin is regarded as one of the most highly erodible areas in China. Desert comprises 64% of the land use in the Basin, but the desert–oasis ecotone plays a prominent role in maintaining oasis ecological security and stability. Yet, little is known concerning the magnitude of windblown sed...

  3. 42 CFR 488.68 - State Agency responsibilities for OASIS collection and data base requirements.

    Science.gov (United States)

    2010-10-01

    ... operating the OASIS system: (a) Establish and maintain an OASIS database. The State agency or other entity... data; (2) Conduct basic system management activities including hardware and software maintenance, system back-up, and monitoring the status of the database; and (3) Obtain CMS approval before modifying...

  4. The fate of water in the oasis of Ouakda between traditional systems ...

    African Journals Online (AJOL)

    One of the subjects that touch the field of environment is undoubtedly the traditional catchment systems and drainage divide in the oasis. The ancestral techniques such as wells chadouf, quanat, Khettara and foggaras have protected the oasis and the man in the past. These techniques were used in an arid middle by the ...

  5. [Spatial change of the grain-size of aeolian sediments in Qira oasis-desert ecotone, Northwest China].

    Science.gov (United States)

    Lin, Yong Chong; Xu, Li Shuai

    2017-04-18

    In order to understand the environmental influence of oasis-desert ecotone to oasis ecological system, we comparatively analyzed the grain size characteristics of various aeolian sediments, including the sediments in oasis-desert ecotone, shelterbelt and the inside oasis and in Qira River valley. The results showed that the grain size characteristics (including grain-size distribution curve, grain size parameters, and content of different size classes) of sediments in the oasis-desert ecotone were consistent along the prevailing wind direction with a grain-size range of 0.3-200 μm and modal size of 67 μm. All of the sediments were good sorting and mainly composed of suspension components and saltation components, but not denatured saltation and creeping components (>200 μm). They were typically aeolian deposits being short-range transported. The grain sizes of sediments in oasis-desert ecotone were smaller than that in the material sources of Qira River valley and desert (0.3-800 μm), but very similar to those of the modern aeolian deposits in oasis-desert ecotone, shelterbelt and the inside oasis. The denatured saltation and creep components (>200 μm) were suppressed to transport into oasis-desert ecotone because of the high vegetation cover in oasis-desert ecotone. Therefore, like the shelterbelts, the oasis-desert ecotone could also block the invasion of desert. They safeguarded the oasis ecological environment together.

  6. Impact of the configuration of stretching and ocean-atmosphere coupling on tropical cyclone activity in the variable-resolution GCM ARPEGE

    Energy Technology Data Exchange (ETDEWEB)

    Daloz, Anne Sophie; Chauvin, Fabrice [CNRM-GAME, Groupe de Modelisation Grande Echelle et Climat, Toulouse Cedex 1 (France); Roux, Frank [Universite de Toulouse, Laboratoire d' Aerologie, Centre National de la Recherche Scientifique, Toulouse (France)

    2012-11-15

    This study starts by investigating the impact of the configuration of the variable-resolution atmospheric grid on tropical cyclone (TC) activity. The French atmospheric general circulation model ARPEGE, the grid of which is rotated and stretched over the North Atlantic basin, was used with prescribed sea surface temperatures. The study clearly shows that changing the position of the stretching pole strongly modifies the representation of TC activity over the North Atlantic basin. A pole in the centre of the North Atlantic basin provides the best representation of the TC activity for this region. In a second part, the variable-resolution climate model ARPEGE is coupled with the European oceanic global climate model NEMO in order to study the impact of ocean-atmosphere coupling on TC activity over the North Atlantic basin. Two pre-industrial runs, a coupled simulation and a simulation forced by the sea surface temperatures from the coupled one, are compared. The results show that the coupled simulation is more active in the Caribbean Sea and the Gulf of Mexico while the forced simulation is more active over eastern Florida and the eastern Atlantic. The difference in the distribution of TC activity is certainly linked with the location of TC genesis. In the forced simulation, tropical cyclogenesis is closer to the west African coast than in the coupled simulation. Moreover, the difference in TC activity over the eastern Atlantic seems to be related to two different mechanisms: the difference in African easterly wave activity over the west of Africa and the cooling produced, in the coupled simulation, by African easterly waves over the eastern Atlantic. Finally, the last part studies the impact of changing the frequency of ocean-atmosphere coupling on Atlantic TC activity. Increasing the frequency of coupling decreases the density of TC activity over the North Atlantic basin. However, it does not modify the spatial distribution of the TC activity. TC rainfalls are

  7. Emulating atmosphere-ocean and carbon cycle models with a simpler model, MAGICC6 – Part 2: Applications

    Directory of Open Access Journals (Sweden)

    M. Meinshausen

    2011-02-01

    Full Text Available Intercomparisons of coupled atmosphere-ocean general circulation models (AOGCMs and carbon cycle models are important for galvanizing our current scientific knowledge to project future climate. Interpreting such intercomparisons faces major challenges, not least because different models have been forced with different sets of forcing agents. Here, we show how an emulation approach with MAGICC6 can address such problems. In a companion paper (Meinshausen et al., 2011a, we show how the lower complexity carbon cycle-climate model MAGICC6 can be calibrated to emulate, with considerable accuracy, globally aggregated characteristics of these more complex models. Building on that, we examine here the Coupled Model Intercomparison Project's Phase 3 results (CMIP3. If forcing agents missed by individual AOGCMs in CMIP3 are considered, this reduces ensemble average temperature change from pre-industrial times to 2100 under SRES A1B by 0.4 °C. Differences in the results from the 1980 to 1999 base period (as reported in IPCC AR4 to 2100 are negligible, however, although there are some differences in the trajectories over the 21st century. In a second part of this study, we consider the new RCP scenarios that are to be investigated under the forthcoming CMIP5 intercomparison for the IPCC Fifth Assessment Report. For the highest scenario, RCP8.5, relative to pre-industrial levels, we project a median warming of around 4.6 °C by 2100 and more than 7 °C by 2300. For the lowest RCP scenario, RCP3-PD, the corresponding warming is around 1.5 °C by 2100, decreasing to around 1.1 °C by 2300 based on our AOGCM and carbon cycle model emulations. Implied cumulative CO2 emissions over the 21st century for RCP8.5 and RCP3-PD are 1881 GtC (1697 to 2034 GtC, 80% uncertainty range and 381 GtC (334 to 488 GtC, when prescribing CO2 concentrations and accounting for uncertainty in the carbon cycle. Lastly, we assess the reasons why a previous MAGICC

  8. Resources to Transform Undergraduate Geoscience Education: Activities in Support of Earth, Oceans and Atmospheric Sciences Faculty, and Future Plans

    Science.gov (United States)

    Ryan, J. G.; Singer, J.

    2013-12-01

    The NSF offers funding programs that support geoscience education spanning atmospheric, oceans, and Earth sciences, as well as environmental science, climate change and sustainability, and research on learning. The 'Resources to Transform Undergraduate Geoscience Education' (RTUGeoEd) is an NSF Transforming Undergraduate Education in STEM (TUES) Type 2 special project aimed at supporting college-level geoscience faculty at all types of institutions. The project's goals are to carry out activities and create digital resources that encourage the geoscience community to submit proposals that impact their courses and classroom infrastructure through innovative changes in instructional practice, and contribute to making transformative changes that impact student learning outcomes and lead to other educational benefits. In the past year information sessions were held during several national and regional professional meetings, including the GSA Southeastern and South-Central Section meetings. A three-day proposal-writing workshop for faculty planning to apply to the TUES program was held at the University of South Florida - Tampa. During the workshop, faculty learned about the program and key elements of a proposal, including: the need to demonstrate awareness of prior efforts within and outside the geosciences and how the proposed project builds upon this knowledge base; need to fully justify budget and role of members of the project team; project evaluation and what matters in selecting a project evaluator; and effective dissemination practices. Participants also spent time developing their proposal benefitting from advice and feedback from workshop facilitators. Survey data gathered from workshop participants point to a consistent set of challenges in seeking grant support for a desired educational innovation, including poor understanding of the educational literature, of available funding programs, and of learning assessment and project evaluation. Many also noted

  9. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of an atmospheric dispersion model with an improved deposition scheme and oceanic dispersion model

    Energy Technology Data Exchange (ETDEWEB)

    Katata, G.; Chino, M.; Kobayashi, T. [Japan Atomic Energy Agency (JAEA), Ibaraki (Japan); and others

    2015-07-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I{sub 2} and CH{sub 3}I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of

  10. Heavy Rainfall Episodes in the Eastern Northeast Brazil Linked to Large-Scale Ocean-Atmosphere Conditions in the Tropical Atlantic

    Directory of Open Access Journals (Sweden)

    Yves K. Kouadio

    2012-01-01

    Full Text Available Relationships between simultaneous occurrences of distinctive atmospheric easterly wave (EW signatures that cross the south-equatorial Atlantic, intense mesoscale convective systems (lifespan > 2 hour that propagate westward over the western south-equatorial Atlantic, and subsequent strong rainfall episodes (anomaly > 10 mm·day−1 that occur in eastern Northeast Brazil (ENEB are investigated. Using a simple diagnostic analysis, twelve cases with EW lifespan ranging between 3 and 8 days and a mean velocity of 8 m·s−1 were selected and documented during each rainy season of 2004, 2005, and 2006. These cases, which represent 50% of the total number of strong rainfall episodes and 60% of the rainfall amount over the ENEB, were concomitant with an acceleration of the trade winds over the south-equatorial Atlantic, an excess of moisture transported westward from Africa to America, and a strengthening of the convective activity in the oceanic region close to Brazil. Most of these episodes occurred during positive sea surface temperature anomaly patterns over the entire south-equatorial Atlantic and low-frequency warm conditions within the oceanic mixing layer. A real-time monitoring and the simulation of this ocean-atmosphere relationship could help in forecasting such dramatic rainfall events.

  11. Polarization measurements made on LFRA and OASIS emitter arrays

    Science.gov (United States)

    Geske, Jon; Sparkman, Kevin; Oleson, Jim; Laveigne, Joe; Sieglinger, Breck; Marlow, Steve; Lowry, Heard; Burns, James

    2008-04-01

    Polarization is increasingly being considered as a method of discrimination in passive sensing applications. In this paper the degree of polarization of the thermal emission from the emitter arrays of two new Santa Barbara Infrared (SBIR) micro-bolometer resistor array scene projectors was characterized at ambient temperature and at 77 K. The emitter arrays characterized were from the Large Format Resistive Array (LFRA) and the Optimized Arrays for Space-Background Infrared Simulation (OASIS) scene projectors. This paper reports the results of this testing.

  12. Determination of ocean/atmosphere carbon dioxide flux within OMP survey area. Final technical progress report, June, 1 1993--May 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Chipman, D.W.; Takahashi, T.

    1995-10-17

    Determination of the net flux of atmospheric CO{sub 2} with the ocean at the continental margin is one of the three principal goals of the Ocean Margins Program. The work reported here represents the initial phase of that determination, as carried out during two cruises within the OMP survey area in 1993 and 1994. The interannual variability was addressed through the occupation of hydrographic stations of nearly identical location one year apart, while the spatial variability in the air-sea PCO{sub 2} difference (ApCO{sub 2}), representing the driving force for net CO{sub 2} flux, was addressed during a survey of much of the continental shelf between the survey area off North Carolina and Georges Bank. Not addressed by the initial cruises was the seasonal variability of the net CO{sub 2} flux, since both scoping cruises were mounted during the same season of the respective years.

  13. Techniques for asynchronous and periodically-synchronous coupling of atmosphere and ocean models. Pt. 1. General strategy and application to the cyclo-stationary case

    Energy Technology Data Exchange (ETDEWEB)

    Sausen, R [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Voss, R [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)

    1995-07-01

    Asynchronous and periodically-synchronous schemes for coupling atmosphere and ocean models are presented. The performance of the schemes is tested by simulating the climatic response to a step function forcing and to a gradually increasing forcing with a simple zero-dimensional non-linear energy balance model. Both the initial transient response and the asymptotic approach of the equilibrium state are studied. If no annual cycle is allowed the asynchronous coupling technique proves to be a suitable tool. However, if the annual cycle is retained, the periodically-synchronous coupling technique reproduces the results of the synchronously coupled runs with smaller bias. In this case it is important that the total length of one synchronous period and one ocean only period is not a multiple of 6 months. (orig.)

  14. Reaching out in new Ways: Bridging the gap Between Science and Media Through the National Oceanic and Atmospheric Administration's Office of Ocean Exploration

    Science.gov (United States)

    Gorell, F. R.; Martinez, C.

    2006-12-01

    NOAA's Office of Ocean Exploration (OE) was created in response to the recommendations of the President's Panel on Ocean Exploration in 2000. With the establishment of OE, NOAA developed a great opportunity to reach out to teachers, students, and the general public to share the excitement of discovery. As exciting expeditions are the core of our NOAA program, outreach efforts are focused around these cruises. Through various initiatives, OE works with the science community to share the excitement of ocean science and discovery with a wide variety of audiences. Initiatives include media events held during port calls, media conference calls arranged with scientists at sea, journalists' participation in expeditions, and select interviews with scientist-explorers. NOAA OE is now poised to initiate a major ongoing satellite-based education and public outreach program from its new dedicated research vessel, the Okeanos Explorer that will become operational in 2008. Through telepresence technology designed by the Institute for Exploration (IFE) in Mystic, CT, expeditions can be managed `virtually' by scientists working from Science Command Centers on land, live education broadcasts can be produced in real-time, and media events can be held through shore-based consoles connected to scientists at sea. Three pilot programs were successfully completed in the past few years demonstrating the potential for this new technology to allow for unlimited access to data, including video, from expeditions, sharing in real-time the excitement of discovery through multiple virtual pathways. News media provide a powerful means to inform and educate the public. In some cases, scientists may believe that interaction with media representatives poses risks unmatched by rewards. While it is important to serve the public's right to know, scientist-explorers on NOAA-sponsored ocean expeditions have a recognized interest in protecting certain data, including images, for a number of legitimate

  15. Current meter components and other data from fixed platforms from TOGA Area - Pacific (30 N to 30 S) and other locations in support of the Tropical Ocean Global Atmosphere (TOGA) and the Equatorial Pacific Ocean Climate Studies (EPOCS) projects from 1989-04-16 to 1990-05-14 (NODC Accession 9200266)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter components data were collected from fixed platforms from the TOGA Area - Pacific (30 N to 30 S) and other locations from 16 April 1989 to 14 May 1990....

  16. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from MEIRING NAUDE, FRAAY R/K and FRANK HARVEY R/K in the Indian Ocean and South Atlantic Ocean from 1966-01-19 to 1979-03-23 (NODC Accession 8200037)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of Bathythermograph data extracted from a tape of physical oceanographic data submitted by the National Research Institute of Oceanography...

  17. Underway pCO2 Measurements in Surface Waters and the Atmosphere During the R/V Xue Long Arctic CHINARE2010 Expedition in the North Pacific Ocean, Bering Sea and Arctic Ocean from 2010-07-09 to 2010-09-06 (NCEI Accession 0164193)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0164193 includes Surface underway, chemical, meteorological and physical data collected from R/V Xue Long Arctic CHINARE2010 Expedition in the North...

  18. A conceptual prediction model for seasonal drought processes using atmospheric and oceanic standardized anomalies and its application to four recent severe regional drought events in China

    Science.gov (United States)

    Liu, Z.; LU, G.; He, H.; Wu, Z.; He, J.

    2017-12-01

    Reliable drought prediction is fundamental for seasonal water management. Considering that drought development is closely related to the spatio-temporal evolution of large-scale circulation patterns, we develop a conceptual prediction model of seasonal drought processes based on atmospheric/oceanic Standardized Anomalies (SA). It is essentially the synchronous stepwise regression relationship between 90-day-accumulated atmospheric/oceanic SA-based predictors and 3-month SPI updated daily (SPI3). It is forced with forecasted atmospheric and oceanic variables retrieved from seasonal climate forecast systems, and it can make seamless drought prediction for operational use after a year-to-year calibration. Simulation and prediction of four severe seasonal regional drought processes in China were forced with the NCEP/NCAR reanalysis datasets and the NCEP Climate Forecast System Version 2 (CFSv2) operationally forecasted datasets, respectively. With the help of real-time correction for operational application, model application during four recent severe regional drought events in China revealed that the model is good at development prediction but weak in severity prediction. In addition to weakness in prediction of drought peak, the prediction of drought relief is possible to be predicted as drought recession. This weak performance may be associated with precipitation-causing weather patterns during drought relief. Based on initial virtual analysis on predicted 90-day prospective SPI3 curves, it shows that the 2009/2010 drought in Southwest China and 2014 drought in North China can be predicted and simulated well even for the prospective 1-75 day. In comparison, the prospective 1-45 day may be a feasible and acceptable lead time for simulation and prediction of the 2011 droughts in Southwest China and East China, after which the simulated and predicted developments clearly change.

  19. Application of a Reduced Order Kalman Filter to Initialize a Coupled Atmosphere-Ocean Model: Impact on the Prediction of El Nino

    Science.gov (United States)

    Ballabrera-Poy, Joaquim; Busalacchi, Antonio J.; Murtugudde, Ragu

    2000-01-01

    A reduced order Kalman Filter, based on a simplification of the Singular Evolutive Extended Kalman (SEEK) filter equations, is used to assimilate observed fields of the surface wind stress, sea surface temperature and sea level into the nonlinear coupled ocean-atmosphere model. The SEEK filter projects the Kalman Filter equations onto a subspace defined by the eigenvalue decomposition of the error forecast matrix, allowing its application to high dimensional systems. The Zebiak and Cane model couples a linear reduced gravity ocean model with a single vertical mode atmospheric model of Zebiak. The compatibility between the simplified physics of the model and each observed variable is studied separately and together. The results show the ability of the model to represent the simultaneous value of the wind stress, SST and sea level, when the fields are limited to the latitude band 10 deg S - 10 deg N. In this first application of the Kalman Filter to a coupled ocean-atmosphere prediction model, the sea level fields are assimilated in terms of the Kelvin and Rossby modes of the thermocline depth anomaly. An estimation of the error of these modes is derived from the projection of an estimation of the sea level error over such modes. This method gives a value of 12 for the error of the Kelvin amplitude, and 6 m of error for the Rossby component of the thermocline depth. The ability of the method to reconstruct the state of the equatorial Pacific and predict its time evolution is demonstrated. The method is shown to be quite robust for predictions I up to six months, and able to predict the onset of the 1997 warm event fifteen months before its occurrence.

  20. Ocean Prediction Center

    Science.gov (United States)

    Social Media Facebook Twitter YouTube Search Search For Go NWS All NOAA Weather Analysis & Forecasts of Commerce Ocean Prediction Center National Oceanic and Atmospheric Administration Analysis & Unified Surface Analysis Ocean Ocean Products Ice & Icebergs NIC Ice Products NAIS Iceberg Analysis

  1. Piloting a Geoscience Literacy Exam for Assessing Students' Understanding of Earth, Climate, Atmospheric and Ocean Science Concepts

    Science.gov (United States)

    Steer, D. N.; Iverson, E. A.; Manduca, C. A.

    2013-12-01

    This research seeks to develop valid and reliable questions that faculty can use to assess geoscience literacy across the curriculum. We are particularly interested on effects of curricula developed to teach Earth, Climate, Atmospheric, and Ocean Science concepts in the context of societal issues across the disciplines. This effort is part of the InTeGrate project designed to create a population of college graduates who are poised to use geoscience knowledge in developing solutions to current and future environmental and resource challenges. Details concerning the project are found at http://serc.carleton.edu/integrate/index.html. The Geoscience Literacy Exam (GLE) under development presently includes 90 questions. Each big idea from each literacy document can be probed using one or more of three independent questions: 1) a single answer, multiple choice question aimed at basic understanding or application of key concepts, 2) a multiple correct answer, multiple choice question targeting the analyzing to analysis levels and 3) a short essay question that tests analysis or evaluation cognitive levels. We anticipate multiple-choice scores and the detail and sophistication of essay responses will increase as students engage with the curriculum. As part of the field testing of InTeGrate curricula, faculty collected student responses from classes that involved over 700 students. These responses included eight pre- and post-test multiple-choice questions that covered various concepts across the four literacies. Discrimination indices calculated from the data suggest that the eight tested questions provide a valid measure of literacy within the scope of the concepts covered. Student normalized gains across an academic term with limited InTeGrate exposure (typically two or fewer weeks of InTeGrate curriculum out of 14 weeks) were found to average 16% gain. A small set of control data (250 students in classes from one institution where no InTeGrate curricula were used) was

  2. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  3. Ocean Uses: California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Ocean Uses Atlas Project is an innovative partnership between NOAA's National Marine Protected Areas Center and Marine Conservation Biology Institute. The...

  4. Ocean Disposal Sites

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1972, Congress enacted the Marine Protection, Research, and Sanctuaries Act (MPRSA, also known as the Ocean Dumping Act) to prohibit the dumping of material into...

  5. California Ocean Uses Atlas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a result of the California Ocean Uses Atlas Project: a collaboration between NOAA's National Marine Protected Areas Center and Marine Conservation...

  6. Ocean Acidification Product Suite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists within the ACCRETE (Acidification, Climate, and Coral Reef Ecosystems Team) Lab of AOML_s Ocean Chemistry and Ecosystems Division (OCED) have constructed...

  7. On the radiocarbon record in banded corals: exchange parameters and net transport of 14CO2 between atmosphere and surface ocean

    International Nuclear Information System (INIS)

    Druffel, E.M.; Suess, H.E.

    1983-01-01

    We have made radiocarbon measurements of banded hermatypic corals from Florida, Belize, and the Galapagos Islands. Interpretation is presented here of these previously reported results. These measurements represent the 14 C/ 12 C ratios in dissolved inorganic carbon (DIOC) in the surface ocean waters of the Gulf Stream and the Peru Current at the time of coral ring formation. A depletion in radiocarbon concentration was observed incoral rings that grew from A.D. 1900--1952. It was caused by dilution of existing 14 C levels with dead CO 2 from fossil fuel burning (the Suess effect, or S/sub e/). A similar trend was observed in the distribution of bomb-produced 14 C in corals that had grown during the years following A.D. 1952. The concentration of bomb-produced radiocarbon was much higher in corals from temperate regions (Florida, Belize, Hawaiian Islands) than in corals from tropical regions (Galapagos Islands and Canton Island). The apparent radiocarbon ages of the surface waters in temperate and tropical oceans during the preanthropogenic period range from about 280 to 520 years B.P. (-40 to -69%). At all investigated locations, it is likely that waters at subsurface depths have the same apparent radiocarbon age of about 670 years B.P. From the change of oceanic δ 14 C in the surface during post-bomb times, the approximate annual rate of net input of 14 CO 2 to the ocean waters is calculated to be about 8% of the prevailing 14 C difference between atmosphere and ocean. From this input and from preanthropogenic δ 14 C values found at each location, it can be seen that vertical mixing of water in the Peru Current is about 3 times greater than that in the Gulf Stream

  8. Oasis 2: improved online analysis of small RNA-seq data.

    Science.gov (United States)

    Rahman, Raza-Ur; Gautam, Abhivyakti; Bethune, Jörn; Sattar, Abdul; Fiosins, Maksims; Magruder, Daniel Sumner; Capece, Vincenzo; Shomroni, Orr; Bonn, Stefan

    2018-02-14

    Small RNA molecules play important roles in many biological processes and their dysregulation or dysfunction can cause disease. The current method of choice for genome-wide sRNA expression profiling is deep sequencing. Here we present Oasis 2, which is a new main release of the Oasis web application for the detection, differential expression, and classification of small RNAs in deep sequencing data. Compared to its predecessor Oasis, Oasis 2 features a novel and speed-optimized sRNA detection module that supports the identification of small RNAs in any organism with higher accuracy. Next to the improved detection of small RNAs in a target organism, the software now also recognizes potential cross-species miRNAs and viral and bacterial sRNAs in infected samples. In addition, novel miRNAs can now be queried and visualized interactively, providing essential information for over 700 high-quality miRNA predictions across 14 organisms. Robust biomarker signatures can now be obtained using the novel enhanced classification module. Oasis 2 enables biologists and medical researchers to rapidly analyze and query small RNA deep sequencing data with improved precision, recall, and speed, in an interactive and user-friendly environment. Oasis 2 is implemented in Java, J2EE, mysql, Python, R, PHP and JavaScript. It is freely available at https://oasis.dzne.de.

  9. Long-term outcomes of the Stop Traumatic OASI Morbidity Project (STOMP).

    Science.gov (United States)

    Basu, Maya; Smith, Dot

    2018-06-09

    To evaluate long-term sustainability of the Stop Traumatic OASI Morbidity Project (STOMP) in reducing the incidence of obstetric anal sphincter injury (OASI). A prospective observational study of women undergoing vaginal delivery at a UK district general hospital between September 1, 2014, and February 28, 2017. The principles of STOMP involve encouraging upright positioning, verbal coaching to avoid expulsive pushing and to slow down delivery, and tactile support to the vertex to judge speed and slow down delivery. After a training period, STOMP was implemented for all vaginal deliveries. Clinical and demographic data on women affected by OASI were collected across a 30-month period. The primary outcome measure was the incidence of OASI. There were 8782 vaginal deliveries during the 30-month period after implementation of STOMP. There was a significant decrease in the mean incidence of OASI relative to the 9 months before implementation (P<0.001). There was a significant decrease in the incidence of OASI for both spontaneous vaginal and instrumental deliveries (both P<0.05). There was no change in the frequency of episiotomy. Implementation of STOMP led to a significant decrease in OASI, confirming the sustainability of this approach to improve outcomes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  10. E-Collaboration for Earth Observation (E-CEO) with the example of Contest #3 that focuses on the Atmospheric Correction of Ocean Colour data

    Science.gov (United States)

    Lavender, Samantha; Brito, Fabrice; Aas, Christina; Casu, Francesco; Ribeiro, Rita; Farres, Jordi

    2014-05-01

    Data challenges are becoming the new method to promote innovation within data-intensive applications; building or evolving user communities and potentially developing sustainable commercial services. These can utilise the vast amount of information (both in scope and volume) that's available online, and profits from reduced processing costs. Data Challenges are also closely related to the recent paradigm shift towards e-Science, also referred to as "data-intensive science'. The E-CEO project aims to deliver a collaborative platform that, through Data Challenge Contests, will improve the adoption and outreach of new applications and methods to processes Earth Observation (EO) data. Underneath, the backbone must be a common environment where the applications can be developed, deployed and executed. Then, the results need to be easily published in a common visualization platform for their effective validation, evaluation and transparent peer comparisons. Contest #3 is based around the atmospheric correction (AC) of ocean colour data with a particular focus on the use of auxiliary data files for processing Level 1 (Top of Atmosphere, TOA, calibrated radiances/reflectances) to Level 2 products (Bottom of Atmosphere, BOA, calibrated radiances/reflectance and derived products). Scientific researchers commonly accept the auxiliary inputs that they've been provided with and/or use the climatological data that accompanies the processing software; often because it can be difficult to obtain multiple data sources and convert them into a format the software accepts. Therefore, it's proposed to compare various ocean colour AC approaches and in the process study the uncertainties associated with using different meteorological auxiliary products for the processing of Medium Resolution Imaging Spectrometer (MERIS) i.e. the sensitivity of different atmospheric correction input assumptions.

  11. Effects of biochemical and physical processes on concentrations and size distributions of dimethylaminium and trimethylaminium in atmospheric particles from marginal seas of China to the northwest Pacific Ocean

    Science.gov (United States)

    Hu, Q.; Yao, X.; Qu, K.; Cui, Z.; Gao, H.; Xie, H.

    2017-12-01

    This study aim to assess the effects of concentrations and size distributions of aminium ions in atmospheric particles from offshore to open oceans. Size-segregated dimethylaminium (DMA+) and trimethylaminium (TMA+) in atmospheric particles were measured during March-May, 2014. One cruise was over marginal seas of China, in which the concentrations of DMA+ and TMA+ in PM0.056-10 varied from 0.08 nmol m-3 to 0.43 nmol m-3 and from 0.10 to 0.27 nmol m-3, respectively. The two ions both had good positive correlations with subsurface chlorophyll-a maximum and salinity, respectively. The highest concentrations of (DMA+ + TMA+) were observed during cyanobacteria bloom period which happened in subsurface water. The results implied that the concentrations of DMA+ (TMA+) in marine atmospheric particles might be influenced by phytoplankton quantities and species in subsurface seawater. Another cruise was carried out from marginal seas of China to the northwest Pacific Ocean (NWPO). The concentrations of DMA+ and TMA+ in PM0.056-1.8 varied from 0.19 nmol m-3 to 1.53 nmol m-3 and from 0.57 to 3.85 nmol m-3, respectively. The highest (lowest) concentrations of (DMA+ + TMA+) were observed near the cyclonic (anticyclonic) eddy, indicating that the cyclonic (anticyclonic) eddy with high (low) chlorophyll-a enhanced (suppressed) DMA+ (TMA+) production in atmospheric particles. In addition, the dominant particle modes less than 0.2 μm for DMA+ (TMA+) were observed, ie., 0.13±0.02 μm for DMA+ over marginal seas of China, and 0.08±0.00 μm for TMA+ in NWPO, but if they were emitted via bubble bursting needed to be further researched.

  12. Isotope variations of hydrogen, carbon and nitrogen in florae from the Schirmacher Oasis, East Antarctica

    International Nuclear Information System (INIS)

    Strauch, G.; Haendel, D.; Maass, I.; Muehle, K.; Runge, A.

    1982-01-01

    Comparative biochemical and isotope-chemical investigations of cosmopolitical plants open up ways of obtaining parameters from different parts of the earth which are characterized by variations in the habitat due to different environments. As an Antarctic oasis the Schirmacher Oasis disposes of adequate favourable ecological conditions for the growth of lower plants. In the present paper results of isotope studies of lichens, mosses and algae of the Schirmacher Oasis are given and peculiarities of the habitats which influence the isotope contents of the plants are discussed. (author)

  13. Deuterium and 18O variations in lakes of the Schirmacher Oasis (East Antarctica)

    International Nuclear Information System (INIS)

    Richter, W.; Strauch, G.

    1983-01-01

    As a snow and icefree rock area the Schirmacher Oasis (Dronning Maud Land) is situated on the coast of the Antartic continent between inland and shelf ice. In the area of the oasis different exogenic conditions have produced multiform types of lake basins. In the present report first results about isotope hydrological relations in the lakes of the Schirmacher Oasis are discussed. The lakes can be classified by isotope hydrological parameters into different groups. The classification depends on in- and outflow, evaporation processes, nature of inflow and location. (author)

  14. Deuterium and /sup 18/O variations in lakes of the Schirmacher Oasis (East Antarctica)

    Energy Technology Data Exchange (ETDEWEB)

    Richter, W.; Strauch, G. (Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1983-05-01

    As a snow and icefree rock area the Schirmacher Oasis (Dronning Maud Land) is situated on the coast of the Antartic continent between inland and shelf ice. In the area of the oasis different exogenic conditions have produced multiform types of lake basins. In the present report first results about isotope hydrological relations in the lakes of the Schirmacher Oasis are discussed. The lakes can be classified by isotope hydrological parameters into different groups. The classification depends on in- and outflow, evaporation processes, nature of inflow and location.

  15. Holocene North Atlantic Overturning in an atmosphere-ocean-sea-ice model compared to proxy-based reconstructions

    NARCIS (Netherlands)

    Blaschek, M.; Renssen, H.; Kissel, C.; Thornalley, D.

    2015-01-01

    Climate and ocean circulation in the North Atlantic region changed over the course of the Holocene, partly because of disintegrating ice sheets and partly because of an orbital-induced insolation trend. In the Nordic Seas, this impact was accompanied by a rather small, but significant, amount of

  16. Massive volcanism at the Permian-Triassic boundary and its impact on the isotopic composition of the ocean and atmosphere

    DEFF Research Database (Denmark)

    Korte, Christoph; Pande, P.; Kalia, P.

    2010-01-01

    and a higher, occasionally double-minimum in the lower I. isarcica Zone. It is unlikely that the short-lived phenomena, such as a breakdown in biological productivity due to catastrophic mass extinction, a sudden release of oceanic methane hydrates or meteorite impact(s), could have been the main control...

  17. Increasing trend of `Break-Monsoon` conditions over India — Role of ocean–atmosphere processes in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Krishnan, R.; Sankar, S.; Unnikrishnan, A.S.; Pai, D.S.

    integrated moisture transport; the findings also point to the role of sea surface temperature (SST) warming trend (0.015 degrees C year sup(-1)) in the tropical eastern Indian Ocean (IO) in inducing anomalous changes favorable for the increased propensity...

  18. Separation of atmospheric, oceanic and hydrological polar motion excitation mechanisms based on a combination of geometric and gravimetric space observations

    Science.gov (United States)

    Göttl, F.; Schmidt, M.; Seitz, F.; Bloßfeld, M.

    2015-04-01

    The goal of our study is to determine accurate time series of geophysical Earth rotation excitations to learn more about global dynamic processes in the Earth system. For this purpose, we developed an adjustment model which allows to combine precise observations from space geodetic observation systems, such as Satellite Laser Ranging (SLR), Global Navigation Satellite Systems, Very Long Baseline Interferometry, Doppler Orbit determination and Radiopositioning Integrated on Satellite, satellite altimetry and satellite gravimetry in order to separate geophysical excitation mechanisms of Earth rotation. Three polar motion time series are applied to derive the polar motion excitation functions (integral effect). Furthermore we use five time variable gravity field solutions from Gravity Recovery and Climate Experiment to determine not only the integral mass effect but also the oceanic and hydrological mass effects by applying suitable filter techniques and a land-ocean mask. For comparison the integral mass effect is also derived from degree 2 potential coefficients that are estimated from SLR observations. The oceanic mass effect is also determined from sea level anomalies observed by satellite altimetry by reducing the steric sea level anomalies derived from temperature and salinity fields of the oceans. Due to the combination of all geodetic estimated excitations the weaknesses of the individual processing strategies can be reduced and the technique-specific strengths can be accounted for. The formal errors of the adjusted geodetic solutions are smaller than the RMS differences of the geophysical model solutions. The improved excitation time series can be used to improve the geophysical modeling.

  19. Atmospheric correction of SeaWiFS ocean color imagery in the presence of absorbing aerosols off the Indian coast using a neuro-variational method

    Science.gov (United States)

    Brajard, J.; Moulin, C.; Thiria, S.

    2008-10-01

    This paper presents a comparison of the atmospheric correction accuracy between the standard sea-viewing wide field-of-view sensor (SeaWiFS) algorithm and the NeuroVaria algorithm for the ocean off the Indian coast in March 1999. NeuroVaria is a general method developed to retrieve aerosol optical properties and water-leaving reflectances for all types of aerosols, including absorbing ones. It has been applied to SeaWiFS images of March 1999, during an episode of transport of absorbing aerosols coming from pollutant sources in India. Water-leaving reflectances and aerosol optical thickness estimated by the two methods were extracted along a transect across the aerosol plume for three days. The comparison showed that NeuroVaria allows the retrieval of oceanic properties in the presence of absorbing aerosols with a better spatial and temporal stability than the standard SeaWiFS algorithm. NeuroVaria was then applied to the available SeaWiFS images over a two-week period. NeuroVaria algorithm retrieves ocean products for a larger number of pixels than the standard one and eliminates most of the discontinuities and artifacts associated with the standard algorithm in presence of absorbing aerosols.

  20. NCEI Standard Product: World Ocean Database (WOD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Ocean Database (WOD) is the world's largest publicly available uniform format quality controlled ocean profile dataset. Ocean profile data are sets of...

  1. Crustal Ages of the Ocean Floor - Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Crustal Ages of the Ocean Floor Poster was created at NGDC using the Crustal Ages of the Ocean Floor database draped digitally over a relief of the ocean floor...

  2. Transport of soil particles to the ocean and their concentration in the marine atmosphere - A case study of marine aerosols collected during the cruises of the Antarctic observation ship Shirase

    International Nuclear Information System (INIS)

    Tanaka, Shigeru; Okamori, Katsutaka; Hashimoto, Yoshikazu

    1991-01-01

    The marine aerosol samples over the West Pacific Ocean, the Indian Ocean, and the Antarctic Ocean, collected during the cruises of the Antarctic observation ship Shirase, were analyzed by X-ray fluorescence. As the results, the average concentration of soil derived elements were 11.9 ng/m 3 for Al, 50.6 ng/m 3 for Si, 12.5 ng/m 3 for Fe, over the West Pacific Ocean. These values were so low as 1/100 of their concentrations in the land. Furthermore, these concentrations over the Indian Ocean and the Antarctic Ocean were extremely low, 6.5 ng/m 3 for Al, 13.4 ng/m 3 for Si, 3.5 ng/m 3 for Fe with average. It is considered that these values are the background concentration of soil derived elements in the marine atmosphere

  3. Thermodynamic structure of the Atmospheric Boundary Layer over the Arabian Sea and the Indian Ocean during pre-INDOEX and INDOEX-FFP campaigns

    Directory of Open Access Journals (Sweden)

    M. V. Ramana

    2004-09-01

    Full Text Available Spatial and temporal variability of the Marine Atmospheric Boundary Layer (MABL height for the Indian Ocean Experiment (INDOEX study period are examined using the data collected through Cross-chained LORAN (Long-Range Aid to Navigation Atmospheric Sounding System (CLASS launchings during the Northern Hemispheric winter monsoon period. This paper reports the results of the analyses of the data collected during the pre-INDOEX (1997 and the INDOEX-First Field Phase (FFP; 1998 in the latitude range 14°N to 20°S over the Arabian Sea and the Indian Ocean. Mixed layer heights are derived from thermodynamic profiles and they indicated the variability of heights ranging from 400m to 1100m during daytime depending upon the location. Mixed layer heights over the Indian Ocean are slightly higher during the INDOEX-FFP than the pre-INDOEX due to anomalous conditions prevailing during the INDOEX-FFP. The trade wind inversion height varied from 2.3km to 4.5km during the pre-INDOEX and from 0.4km to 2.5km during the INDOEX-FFP. Elevated plumes of polluted air (lofted aerosol plumes above the marine boundary layer are observed from thermodynamic profiles of the lower troposphere during the INDOEX-FFP. These elevated plumes are examined using 5-day back trajectory analysis and show that one group of air mass travelled a long way from Saudi Arabia and Iran/Iraq through India before reaching the location of measurement, while the other air mass originates from India and the Bay of Bengal.

  4. Extinction dynamics of a discrete population in an oasis.

    Science.gov (United States)

    Berti, Stefano; Cencini, Massimo; Vergni, Davide; Vulpiani, Angelo

    2015-07-01

    Understanding the conditions ensuring the persistence of a population is an issue of primary importance in population biology. The first theoretical approach to the problem dates back to the 1950s with the Kierstead, Slobodkin, and Skellam (KiSS) model, namely a continuous reaction-diffusion equation for a population growing on a patch of finite size L surrounded by a deadly environment with infinite mortality, i.e., an oasis in a desert. The main outcome of the model is that only patches above a critical size allow for population persistence. Here we introduce an individual-based analog of the KiSS model to investigate the effects of discreteness and demographic stochasticity. In particular, we study the average time to extinction both above and below the critical patch size of the continuous model and investigate the quasistationary distribution of the number of individuals for patch sizes above the critical threshold.

  5. OASIS: a COBOL-11 menu-driven information system

    International Nuclear Information System (INIS)

    Lee, W.F. Jr.

    1982-01-01

    Oak Ridge National Laboratory's Automated Safeguards Information System (OASIS) is a near real-time nuclear materials/precious metals safeguard and accountability control system. Using COBOL and RSTS/E on a dedicated 11/34, the system performs on-line inventory update, inquiry and report functions. Processed transactions consisting of intra-laboratory movements, on-site receipts and off-site shipments are maintained for inquiry and report preparation. A secure, controlled but friendly user environment is maintained by chaining between menu and data manipulation tasks. The use of menus, security and access control, screen manipulation, file access and contention, word processing activities, task size problems and other aspects of this application will be discussed

  6. Geochemistry of coral from Papua New Guinea as a proxy for ENSO ocean-atmosphere interactions in the Pacific Warm Pool

    Science.gov (United States)

    Ayliffe, Linda K.; Bird, Michael I.; Gagan, Michael K.; Isdale, Peter J.; Scott-Gagan, Heather; Parker, Bruce; Griffin, David; Nongkas, Michael; McCulloch, Malcolm T.

    2004-12-01

    A Porites sp. coral growing offshore from the Sepik and Ramu Rivers in equatorial northern Papua New Guinea has yielded an accurate 20-year history (1977-1996) of sea surface temperature (SST), river discharge, and wind-induced mixing of the upper water column. Depressions in average SSTs of about 0.5-1.0 °C (indicated by coral Sr/Ca) and markedly diminished freshwater runoff to the coastal ocean (indicated by coral δ18O, δ13C and UV fluorescence) are evident during the El Niño - Southern Oscillation (ENSO) events of 1982-1983, 1987 and 1991-1993. The perturbations recorded by the coral are in good agreement with changes in instrumental SST and river discharge/precipitation records, which are known to be diagnostic of the response of the Pacific Warm Pool ocean-atmosphere system to El Niño. Consideration of coastal ocean dynamics indicates that the establishment of northwest monsoon winds promotes mixing of near-surface waters to greater depths in the first quarter of most years, making the coral record sensitive to changes in the Asian-Australian monsoon cycle. Sudden cooling of SSTs by ˜1°C following westerly wind episodes, as indicated by the coral Sr/Ca, is consistent with greater mixing in the upper water column at these times. Furthermore, the coral UV fluorescence and oxygen isotope data indicate minimal contribution of river runoff to surface ocean waters at the beginning of most years, during the time of maximum discharge. This abrupt shift in flood-plume behaviour appears to reflect the duration and magnitude of northwest monsoon winds, which tend to disperse flood plume waters to a greater extent in the water column when wind-mixing is enhanced. Our results suggest that a multi-proxy geochemical approach to the production of long coral records should provide comprehensive reconstructions of tropical paleoclimate processes operating on interannual timescales.

  7. Microbiological studies in schirmacher oasis, Antarctica: Effect of temperature on bacterial populations

    Digital Repository Service at National Institute of Oceanography (India)

    Matondkar, S.G.P.

    Seasonal and site wise variation in size and diversity of bacterial population was observed in Schirmacher Oasis, Antarctica. Prevailing soil temperature limited the distribution and abundance of groups of bacteria like psychrophiles, psychrotrophs...

  8. Dissolved methane in the Beaufort Sea and the Arctic Ocean, 1992–2009; sources and atmospheric flux

    NARCIS (Netherlands)

    Lorenson, T.D.; Greinert, J.; Coffin, R.B.

    2016-01-01

    Methane concentration and isotopic composition was measured in ice-covered and ice-free waters of theArctic Ocean during 11 surveys spanning the years of 1992–1995 and 2009. During ice-free periods, methaneflux from the Beaufort shelf varies from 0.14 mg CH4 m22 d21 to 0.43 mg CH4 m22 d21. Maximum

  9. Land-total and Ocean-total Precipitation and Evaporation from a Community Atmosphere Model version 5 Perturbed Parameter Ensemble

    Energy Technology Data Exchange (ETDEWEB)

    Covey, Curt [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lucas, Donald D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Trenberth, Kevin E. [National Center for Atmospheric Research, Boulder, CO (United States)

    2016-03-02

    This document presents the large scale water budget statistics of a perturbed input-parameter ensemble of atmospheric model runs. The model is Version 5.1.02 of the Community Atmosphere Model (CAM). These runs are the “C-Ensemble” described by Qian et al., “Parametric Sensitivity Analysis of Precipitation at Global and Local Scales in the Community Atmosphere Model CAM5” (Journal of Advances in Modeling the Earth System, 2015). As noted by Qian et al., the simulations are “AMIP type” with temperature and sea ice boundary conditions chosen to match surface observations for the five year period 2000-2004. There are 1100 ensemble members in addition to one run with default inputparameter values.

  10. Ship track for Life on the Edge 2003: Exploring Deep Ocean Habitats - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ship track of the R/V Seward Johnson during the "Life on the Edge 2003: Exploring Deep Ocean Habitats" expedition sponsored by the National Oceanic and Atmospheric...

  11. Ship Track for The Hidden Ocean Arctic 2005 - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ship track of the US Coast Guard icebreaker Healy during the "Hidden Ocean Arctic 2005" expedition sponsored by the National Oceanic and Atmospheric Administration...

  12. Regional variations in provenance and abundance of ice-rafted clasts in Arctic Ocean sediments: Implications for the configuration of late Quaternary oceanic and atmospheric circulation in the Arctic

    Science.gov (United States)

    Phillips, R.L.; Grantz, A.

    2001-01-01

    The composition and distribution of ice-rafted glacial erratics in late Quaternary sediments define the major current systems of the Arctic Ocean and identify two distinct continental sources for the erratics. In the southern Amerasia basin up to 70% of the erratics are dolostones and limestones (the Amerasia suite) that originated in the carbonate-rich Paleozoic terranes of the Canadian Arctic Islands. These clasts reached the Arctic Ocean in glaciers and were ice-rafted to the core sites in the clockwise Beaufort Gyre. The concentration of erratics decreases northward by 98% along the trend of the gyre from southeastern Canada basin to Makarov basin. The concentration of erratics then triples across the Makarov basin flank of Lomonosov Ridge and siltstone, sandstone and siliceous clasts become dominant in cores from the ridge and the Eurasia basin (the Eurasia suite). The bedrock source for the siltstone and sandstone clasts is uncertain, but bedrock distribution and the distribution of glaciation in northern Eurasia suggest the Taymyr Peninsula-Kara Sea regions. The pattern of clast distribution in the Arctic Ocean sediments and the sharp northward decrease in concentration of clasts of Canadian Arctic Island provenance in the Amerasia basin support the conclusion that the modem circulation pattern of the Arctic Ocean, with the Beaufort Gyre dominant in the Amerasia basin and the Transpolar drift dominant in the Eurasia basin, has controlled both sea-ice and glacial iceberg drift in the Arctic Ocean during interglacial intervals since at least the late Pleistocene. The abruptness of the change in both clast composition and concentration on the Makarov basin flank of Lomonosov Ridge also suggests that the boundary between the Beaufort Gyre and the Transpolar Drift has been relatively stable during interglacials since that time. Because the Beaufort Gyre is wind-driven our data, in conjunction with the westerly directed orientation of sand dunes that formed during

  13. RELATIONSHIPS BETWEEN SEA SURFACE TEMPERATURE, LARGE-SCALE ATMOSPHERIC CIRCULATION, AND CONVECTION OVER THE TROPICAL INDIAN AND PACIFIC OCEANS

    Directory of Open Access Journals (Sweden)

    Orbita Roswintiarti

    2008-07-01

    Full Text Available In this paper, the quantitative estimates of the effect of large-scale circulations on the sea surface temperature (SST-tropical convection relationship and the effect of SST on the large-scale circulation-convection relationship over the tropical Indian and Pacific Oceans are presented. Although convection tends to maximize at warm SSTs, increased deep convection is also determined by the divergence (DIV associated with large-scale circulation. An analysis of the relationship between SST and deep convection shows that under subsidence and clear conditions, there is a decrease in convection or increase in Outgoing Longwave Radiation (OLR at a maximum rate of 3.4 Wm-2 °C-1. In the SST range of 25°C to 29.5°C, a large increase in deep convection (decrease in OLR occurs in the tropical Indian and Pacific Oceans. The OLR reduction is found to be a strong function of the large-scale circulation in the Indian and western Pacific Oceans. Under a weak large-scale circulation, the rate of OLR reduction is about    -3.5 Wm-2 °C-1 to -8.1 Wm-2 °C-1. Under the influence of strong rising motions, the rate can increase to about -12.5 Wm-2 °C-1 for the same SST range. The overall relationship between large-scale circulation and deep convection is nearly linear. A maximum rate of OLR reduction with respect to DIV is -6.1 Wm-2 (10-6 s-1 in the western Pacific Ocean. It is also found that the DIV-OLR relationship is less dependent on SST. For example, the rate of OLR reduction over the western Pacific Ocean for 26°C < SST £ 27°C is -4.2 Wm-2 (10-6 s-1, while that for 28°C < SST £ 29°C is  -5.1 Wm-2 (10-6 s-1. These results are expected to have a great importance for climate feedback mechanisms associated with cloud