Microwave and Infrared Radiances Assimilation for Weather Forecasting

The Community Radiative Transfer Model (CRTM) has been implemented in the Gridpoint Statistical Interpolation (GSI) system at the National Center for Environmental Prediction (NCEP) to simulate microwave and infrared radiances. We investigate impacts on analysis from a recent sensor, Special Sensor Microwave Imager Sounder (SSMIS). Both retrievals and radiance assimilation using the SSMIS show that SSMIS is unique in precisely determining stratospheric temperatures. We also utilize the SSMIS radiance for studying Hurricane Katrina. A "control-run" using current NCEP analysis field and a "test-run" using additional SSMIS data are compared. It shows again that the SSMIS radiance assimilation is helpful for hurricane forecasting.