Statistical Analysis of the Life Cycle of Isolated Tropical Cold Cloud Systems Using MTSAT-1R and TRMM Data

Abstract

bservations from the Multifunctional Transport Satellite-1R (MTSAT-1R) and the Tropical Rainfall Measuring Mission (TRMM) satellites are analyzed to show the universal view of the cloud life cycle, including the changes of vertical structure of rainfall, over the Maritime Continent and a part of the tropical western Pacific, with a focus on the isolated cold cloud systems. Temporally connected cold cloud systems are identified by a cloud tracking procedure and compared with the collocated observations from TRMM. Clear life cycle changes of the average reflectivity profile from the Precipitation Radar (PR), such as those of radar echo height and the brightband feature, are statistically confirmed over the ocean area. Systems with a lifetime of 5 h show a behavior similar to those of typical mesoscale convective systems, with an extension of anvil clouds up to an area of about 6000 km2 as a delayed response to the earlier intense convection, indicated by the peaks of rain rates and radar echo height at the early stages. In contrast, the 2-h lifetime systems decay rapidly and do not produce an extension of cloud and precipitation. The results also show that the difference between rainfall estimates of the TRMM Microwave Imager (TMI) and PR depends on the phase in the lifetime. TMI tends to provide higher conditional average rain rates at the mature phase than that of PR.