Improved Goddard profiling (GPROF) database over the Korean Peninsula and its impact on TRMM TMI rainfall

Based on the comparison of TMI measurements and the AWS rain rates, characteristics of rain systems over the Korean Peninsula during summer were examined. It was found that the TMI brightness temperatures (TBs) at high frequency (85 GHz) are generally higher than those in GPROF database for the same rain rate. With these characteristics kept in mind, cloud resolving model simulations were performed by modifying intercept values in the Marshall-Palmer size distribution relationship. The intercept values of graupel and snow were assumed to twice the default value (snow: 1.0 x 10(8) m(-4), Graupel: 4.0 x 10(6) m(-4)). Microwave brightness temperatures at passive microwave radiometer frequencies and vertical reflectivity at precipitation radar frequency are calculated by repeated application of the one-dimensional version of Eddington's approximation(1). The hydrometeor profiles were selected by comparing with TRMM PR reflectivities. By adding those selected profiles to the convective profiles of GPROF database, we modified database for the rain retrieval over the Korean Peninsula. Rainfall retrievals by using the new database show that quality is significantly improved, indicating the need of algorithm locally more suitable.