Satellite Data Assimilation

During this decade, planned satellite missions 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 (see Fig. 1). These data have and will exhibit accuracies and spatial, spectral and temporal resolutions never before achieved and will continue to allow improvements in our environmental prediction capability. To ensure the maximum benefit from investment in the space based global observing system is realized, the advancement of satellite data assimilation science has involved and will continue to involve continual upgrading of community radiative transfer models such as RTTOV and the JCSDA Community Radiative Transfer Model (CRTM). These community radiative transfer models are continually upgraded to allow the use of both current and many future satellite instruments, including, for example, the Advanced Baseline Imager (ABI) to be flown on GOES-R, the Atmospheric Infrared Sounder (AIRS). They also provide snow, ice and land emissivity models/databases for improving the use of Infrared (IR) and microwave sounding instruments over ocean, non-ocean and frozen regions. This latter activity is very important as the use of sounding data over ice and snow and land in operational systems still remains limited, with a related loss of information in the lower troposphere over large regions. The community radiative transfer model upgrades have also involved preparation for use of data from the Meteorological Operational Polar Satellite’s (METOP’s) Infrared Atmospheric Sounding Interferometer (IASI), the Advanced Microwave Sounding Unit (AMSU), the Microwave Humidity Sounder (MHS), the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager/Sounder (SSMIS) and the Challenging Mini Payload (CHAMP) and The Co nstellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Global Positioning System (GPS) based radio-occultation systems. Observing System Experiments (OSEs), Data Impact Studies and Observing System Simulation Experiments (OSSEs) have also been part of the work pursued by the global NWP community to ensure maximum benefit is obtained from the space-based observing system. Recent advances, in answer to this challenge, include the demonstration of the significant benefits to Northern and Southern Hemisphere forecasts from satellite data generally and particular impacts from ultraspectral (AIRS and IASI) radiance assimilation using the