ATOVS Microwave Sounding Observation Cycling Assimilation on a Tropical Cyclone Case in 2012

摘要

This study introduces constructions of the satellite observation cycling assimilation system in National Satellite Meteorological Center (NSMC)/China Meteorological Administration (CMA). A typhoon (1209 Saola) is chosen as a test case to check performance of the cycling assimilation system at low resolution. Three experiments are designed: control, ATOVS microwave observation assimilation and forecasting with cold start, assimilation and forecasting with warm start. Compared with the cold start forecasting, the cycling forecasting scheme (with warm restart and assimilation every 6 hours) showed advantages in describing Tropical Cyclones (TC) in details. As for track and intensity predictions, the two assimilation experiments were superior to the control experiment. Especially, the cycling experiment (with warm restart) is better than the cold start experiment for the first day, third day, and day before its landfall, but does not perform well during TC's mature stage, which may suggest that this model could not present the typhoon Saola well during TC mature stage with a low resolution. Results also demonstrate that this scheme is fine during TC's slow intensification period.