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This report discusses the design and implementation of a specialized forecasting system that was set up to support the observational component of the Labrador Sea Deep Convection Experiment. This ongoing experiment is a multidisciplinary program of observations, theory, and modeling aimed at improving our knowledge of the deep convection process in the ocean, and the air–sea interaction that forces it. The observational part of the program was centered around a cruise of the R/V Knorr during winter 1997, as well as several complementary meteorological research flights. To aid the planning of ship and aircraft operations a specially tailored mesoscale model was run over the Labrador Sea, with the model output postprocessed and transferred to a remote field base. The benefits of using a warm-start analysis cycle in the model are discussed. The utility of the forecasting system is illustrated through a description of the flight planning process for several cases. The forecasts proved to be invaluable both in ship operations and in putting the aircraft in the right place at the right time. In writing this narrative the authors hope to encourage the use of similar forecasting systems in the support of future field programs, something that is becoming increasingly possible with the rise in real-time numerical weather prediction.
This report discusses the design and implementation of a specialized forecasting system that was set up to support the observational component of the Labrador Sea Deep Convection Experiment. This ongoing experiment is a multidisciplinary program of observations, theory, and modeling aimed at improving our knowledge of the deep convection process in the ocean, and the air–sea interaction that forces it. The observational part of the program was centered around a cruise of the R/V Knorr during winter 1997, as well as several complementary meteorological research flights. To aid the planning of ship and aircraft operations a specially tailored mesoscale model was run over the Labrador Sea, with the model output postprocessed and transferred to a remote field base. The benefits of using a warm-start analysis cycle in the model are discussed. The utility of the forecasting system is illustrated through a description of the flight planning process for several cases. The forecasts proved to be invaluable both in ship operations and in putting the aircraft in the right place at the right time. In writing this narrative the authors hope to encourage the use of similar forecasting systems in the support of future field programs, something that is becoming increasingly possible with the rise in real-time numerical weather prediction.
The Joint Center for Satellite Data Assimilation (JCSDA) was established by NASA and NOAA in 2001, with Department of Defense (DoD) agencies becoming partners in 2002. The goal of JCSDA is to accelerate the use of observations from Earth-orbiting satellites in operational environmental analysis and prediction models for the purpose of improving weather, ocean, climate, and air quality forecasts and the accuracy of climate datasets. Advanced instruments of current and planned satellite missions do and will increasingly provide large volumes of data related to the atmospheric, oceanic, and land surface state. During this decade, this will result in a five order of magnitude increase in the volume of data available for use by the operational and research weather, ocean, and climate communities. These data will exhibit accuracies and spatial, spectral, and temporal resolutions never before achieved. JCSDA will help ensure that the maximum benefit from investment in the space-based global observation system is realized. JCSDA will accelerate the use of satellite data from both operational and experimental spacecraft for weather and climate prediction systems. To this end, the advancement of data assimilation science by JCSDA has included the establishment of the JCSDA Community Radiative Transfer Model (CRTM), which has continual upgrades to allow for the effective use of current and many future satellite instruments. This and other activity within JCSDA have been supported by both internal and external (generally university based) research. Another key activity within JCSDA has been to lay the groundwork for and to establish common NWP model and data assimilation infrastructure for accessing new satellite data and optimizing the use of these data in operational models. As a result of this activity, common assimilation infrastructure has been established at NOAA and NASA and this will assist in a coordinated and integrated move to four-dimensional assimilation among the partner agencies.
This paper discusses the establishment of JCSDA and its mission, goals, and science priorities. It also discusses recent advances made by JCSDA, and planned future developments.
The Joint Center for Satellite Data Assimilation (JCSDA) was established by NASA and NOAA in 2001, with Department of Defense (DoD) agencies becoming partners in 2002. The goal of JCSDA is to accelerate the use of observations from Earth-orbiting satellites in operational environmental analysis and prediction models for the purpose of improving weather, ocean, climate, and air quality forecasts and the accuracy of climate datasets. Advanced instruments of current and planned satellite missions do and will increasingly provide large volumes of data related to the atmospheric, oceanic, and land surface state. During this decade, this will result in a five order of magnitude increase in the volume of data available for use by the operational and research weather, ocean, and climate communities. These data will exhibit accuracies and spatial, spectral, and temporal resolutions never before achieved. JCSDA will help ensure that the maximum benefit from investment in the space-based global observation system is realized. JCSDA will accelerate the use of satellite data from both operational and experimental spacecraft for weather and climate prediction systems. To this end, the advancement of data assimilation science by JCSDA has included the establishment of the JCSDA Community Radiative Transfer Model (CRTM), which has continual upgrades to allow for the effective use of current and many future satellite instruments. This and other activity within JCSDA have been supported by both internal and external (generally university based) research. Another key activity within JCSDA has been to lay the groundwork for and to establish common NWP model and data assimilation infrastructure for accessing new satellite data and optimizing the use of these data in operational models. As a result of this activity, common assimilation infrastructure has been established at NOAA and NASA and this will assist in a coordinated and integrated move to four-dimensional assimilation among the partner agencies.
This paper discusses the establishment of JCSDA and its mission, goals, and science priorities. It also discusses recent advances made by JCSDA, and planned future developments.
Abstract
Well-known problems trouble coupled general circulation models of the eastern Atlantic and Pacific Ocean basins. Model climates are significantly more symmetric about the equator than is observed. Model sea surface temperatures are biased warm south and southeast of the equator, and the atmosphere is too rainy within a band south of the equator. Near-coastal eastern equatorial SSTs are too warm, producing a zonal SST gradient in the Atlantic opposite in sign to that observed. The U.S. Climate Variability and Predictability Program (CLIVAR) Eastern Tropical Ocean Synthesis Working Group (WG) has pursued an updated assessment of coupled model SST biases, focusing on the surface energy balance components, on regional error sources from clouds, deep convection, winds, and ocean eddies; on the sensitivity to model resolution; and on remote impacts. Motivated by the assessment, the WG makes the following recommendations: 1) encourage identification of the specific parameterizations contributing to the biases in individual models, as these can be model dependent; 2) restrict multimodel intercomparisons to specific processes; 3) encourage development of high-resolution coupled models with a concurrent emphasis on parameterization development of finer-scale ocean and atmosphere features, including low clouds; 4) encourage further availability of all surface flux components from buoys, for longer continuous time periods, in persistently cloudy regions; and 5) focus on the eastern basin coastal oceanic upwelling regions, where further opportunities for observational–modeling synergism exist.
Abstract
Well-known problems trouble coupled general circulation models of the eastern Atlantic and Pacific Ocean basins. Model climates are significantly more symmetric about the equator than is observed. Model sea surface temperatures are biased warm south and southeast of the equator, and the atmosphere is too rainy within a band south of the equator. Near-coastal eastern equatorial SSTs are too warm, producing a zonal SST gradient in the Atlantic opposite in sign to that observed. The U.S. Climate Variability and Predictability Program (CLIVAR) Eastern Tropical Ocean Synthesis Working Group (WG) has pursued an updated assessment of coupled model SST biases, focusing on the surface energy balance components, on regional error sources from clouds, deep convection, winds, and ocean eddies; on the sensitivity to model resolution; and on remote impacts. Motivated by the assessment, the WG makes the following recommendations: 1) encourage identification of the specific parameterizations contributing to the biases in individual models, as these can be model dependent; 2) restrict multimodel intercomparisons to specific processes; 3) encourage development of high-resolution coupled models with a concurrent emphasis on parameterization development of finer-scale ocean and atmosphere features, including low clouds; 4) encourage further availability of all surface flux components from buoys, for longer continuous time periods, in persistently cloudy regions; and 5) focus on the eastern basin coastal oceanic upwelling regions, where further opportunities for observational–modeling synergism exist.
As part of the U.K. contribution to the international Surface Ocean-Lower Atmosphere Study, a series of three related projects—DOGEE, SEASAW, and HiWASE—undertook experimental studies of the processes controlling the physical exchange of gases and sea spray aerosol at the sea surface. The studies share a common goal: to reduce the high degree of uncertainty in current parameterization schemes. The wide variety of measurements made during the studies, which incorporated tracer and surfactant release experiments, included direct eddy correlation fluxes, detailed wave spectra, wind history, photographic retrievals of whitecap fraction, aerosolsize spectra and composition, surfactant concentration, and bubble populations in the ocean mixed layer. Measurements were made during three cruises in the northeast Atlantic on the RRS Discovery during 2006 and 2007; a fourth campaign has been making continuous measurements on the Norwegian weather ship Polarfront since September 2006. This paper provides an overview of the three projects and some of the highlights of the measurement campaigns.
As part of the U.K. contribution to the international Surface Ocean-Lower Atmosphere Study, a series of three related projects—DOGEE, SEASAW, and HiWASE—undertook experimental studies of the processes controlling the physical exchange of gases and sea spray aerosol at the sea surface. The studies share a common goal: to reduce the high degree of uncertainty in current parameterization schemes. The wide variety of measurements made during the studies, which incorporated tracer and surfactant release experiments, included direct eddy correlation fluxes, detailed wave spectra, wind history, photographic retrievals of whitecap fraction, aerosolsize spectra and composition, surfactant concentration, and bubble populations in the ocean mixed layer. Measurements were made during three cruises in the northeast Atlantic on the RRS Discovery during 2006 and 2007; a fourth campaign has been making continuous measurements on the Norwegian weather ship Polarfront since September 2006. This paper provides an overview of the three projects and some of the highlights of the measurement campaigns.
Abstract
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