Precipitation and microphysical characteristics of objectively derived MSC regimes

Instruments on the Tropical Rainfall Measuring Mission (TRMM) satellite have been used to study the precipitation (using the Precipitation Radar) and microphysical characteristics (using the Lightning Imaging Sensor and TRMM Microwave Imager) of precipitation features. The polar orbit of TRMM means that mesoscale convective systems (MCS) are rarely sampled more than once. Geostationary Infrared (IR) studies have been used to study MCS, including their life cycle and dynamics. However, IR only studies are limited, the poor relationship between cloud top temperature and rainfall being well noted in the literature.

This study reports on the comparison between objectively derived MCS regimes and TRMM data using the University of Utah TRMM database. The MCS regimes are derived by K-means cluster analysis using the Japanese Meteorological Agency GMS5 IR1 channel over the Maritime Continent, for the 1998-99 to 2000-2001 monsoon seasons (September to April). Four regimes are identified, short-lived MCS, long-lived MCS and intermediate lifetime MCS propagating eastward and westward. A composite lifecycle of precipitation and microphysics is built up, and the difference between each regime and continental/maritime MCS are studied.