Improving the Characterization of the Battlespace Environment with Satellite Brightness Temperature Assimilation

Satellite observations, particularly in data-sparse regions, are critically important for initializing the Navy's global and mesoscale numerical weather prediction (NWP) models used to provide tactical weather support. Advanced Microwave Sounding Unit A (AMSU-A) and AMSU-B are multi channel passive microwave radiometers that provide global observations of atmospheric temperature and moisture, respectively. Recently, the NRL Atmospheric Variational Data Assimilation System (NAVDAS) began operational assimilation of AMSU-A brightness temperatures T(b)'s for the Navy Operational Global Atmospheric Prediction System (NOGAPS), replacing the assimilation of temperature retrievals. AMSU-A assimilation significantly improves the Northern and Southern Hemisphere forecast skill and tropical cyclone track predictions. Assimilation of AMSU-B humidity profiles improves the representation of NOGAPS upper-tropospheric water vapor, and further reduces tropical cyclone track forecast error. Published in NRL Review 2005, p109-111, 2005.