Tuesday, 13 January 2009
Using TRMM for thunderstom cell identification and lightning climatology
Hall 5 (Phoenix Convention Center)
Since its inception in 1997, the Tropical Rainfall Measurement Mission (TRMM) satellite orbits the global tropics and achieves a number of observations regarding daily rainfall and lightning by means of its varied instrumentation. Among these instruments are the Lightning Imaging Sensor (LIS), Precipitation Radar (PR) and the TRMM Microwave Imager (TMI). An algorithm has been developed that refines the University of Utah's mesoscale features database, resolving individual thunderstorm cells and creating a database of characteristics of these cells (e.g., rainfall rate, storm height, lightning flash rate, etc.) using the LIS, PR and TMI datasets. Analyzing features from the mesoscale database on the convective scale (O[10 km X 10 km]) enables the cloud electrification process to be studied specifically, potentially providing insight into the properties and conditions required, and resulting from, lightning-producing storms. Additionally, the structure and development of convective cells can easily be compared to the features in which these cells initiate. Furthermore, the convective cell database comprises information necessary to determine decadal and seasonal trends in the properties of thunderstorms, specifically those characteristics related to lightning, over the tropics. This study focuses on the methodology of the algorithm and the preliminary results of the climatology of lightning occurrence.