Comparative Microphysical Characteristics of Numerically Simulated Warm-Season Thunderstorms in Diverse Climatic Regimes

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

The Principal Investigator will use an existing three-dimensional, time-dependent quasi-compressible research cloud model to study the bulk microphysical structure of warm?season deep convective storms for diverse geographical environments from tropical to mid?latitude. This project will investigate the effects of the geographical environment on the following volume-integrated properties relating to the storm-scale water cycle: the total condensate mass, the production and depletion of the precipitation within this condensate pool, and especially the partitioning of the mass by hydrometeor types and of the microphysical transfer rates by the individual processes contributing to them. A recently completed project by the Principal Investigator has laid a foundation for the work by simulating and analyzing thunderstorms in the semi-arid High Plains of North America and the humid subtropics. The Principal Investigators will extend their approach to substantially more regions in recognition that: (a) several contrasting North American thunderstorm climatologies have been documented for regions other than those two, (b) several other regions of the world from the Tropics through mid?latitudes are subject to especially frequent or intense convective storms, and (c) in low latitudes, deep convection has repeatedly been observed to be systematically weaker at sea than over land, with significantly different microphysical makeup. The researchers will investigate up to approximately ten locations, subject to availability of data suitably representative of pre-storm environmental conditions for the control experiments. Thunderstorm environments under consideration include the summer monsoon of North America's subtropical desert southwest, tropical and subtropical Asia and Western Europe. Comparison of model results among the control experiments for different regions will emphasize the volume-integrated bulk microphysical properties noted above, and especially the time-averaged percentage breakdowns of their partitioning during the mature phase of a storm. The research, if successful, will be significant to the advancement of knowledge in mesoscale atmospheric dynamics and will increase fundamental understanding of the nature of convective activity under various climatic regimes.