Mechanism of Convective Cloud Triggering and Organization By Cold Pools during Dynamo

Friday, 19 December 2014
Zhe Feng1, Samson M Hagos1, Casey D. Burleyson1, Angela Rowe2, Matus Martini1 and Simon P de Szoeke3, (1)Pacific Northwest National Laboratory, Richland, WA, United States, (2)University of Washington Seattle Campus, Atmospheric Sciences, Seattle, WA, United States, (3)Oregon State University, Corvallis, OR, United States
Cold pools resulting from evaporation of rain in convective downdrafts are important components of meso-scale organization in the tropics. Using combinations of cloud resolving regional model simulations and radar and surface observations obtained during the CINDY2011/DYNAMO/AMIE field campaign, we investigate mechanism of convective cloud triggering and organization at the edge of cold pools. The model simulated cloud population and cold pool statistics compare well with the observations. Comparison of thermodynamics and dynamic conditions at the boundaries of isolated and intersecting cold pools reveals, that deep convection is mainly attributed to larger cloud clusters formed at intersecting cold pool boundaries, as a result of reduced entrainment of environmental air, while stronger sub-cloud layer forced updraft by colliding gust fronts played a secondary role.