The Vertical and Horizontal Characteristics of Mesoscale Convective Systems on a Temporal Scale

Mesoscale Convective Systems (MCSs) are a common precipitative feature in the world's tropical regions and are responsible for over 50% of annual rainfall in these regions. They serve as a critical link between our understanding of atmospheric convection and large-scale circulation, and they are an integral part of the global radiation budget. Yet numerous gaps remain in our knowledge of the characteristics of MCSs in the tropical regions. In particular, more work is needed to understand how their vertical and horizontal structure evolve as a function of time, geography, and atmospheric conditions.

This study uses the Tracked IMERG Mesoscale Precipitation Systems (TIMPS) dataset, the University of Washington's GPMKU dataset, and ECMWF ERA5 Reanalysis hourly data to address these issues. The TIMPS algorithm tracks each tropical MCS in time, and the GPMKU dataset provides corresponding echo-type and vertical structure information. We then analyzed the conditions associated with MCSs that fit within our specified size criteria.

Our results show distinct regional variations, with marked variability existing between both land and ocean sub-regions. Results also agree with past studies that land MCSs have more intense convection. However, ocean MCSs grow to larger sizes. Echo types differ in intensity over land, ocean, and on a regional basis. The environmental conditions associated with the growth and maintenance of MCSs in each geographical region will also be shown. Collectively, these results add to our understanding of the evolution and structure of tropical MCSs on a global and regional scale.