Interactions between shallow clouds and their environment in sheared flows

Abstract:

Shallow clouds act to destabilize the inversion layers that limit their vertical extent. To accurately determine the heat and moisture transport into the inversion layer we must understand how shallow clouds interact with the ambient air. Previous research has concentrated on the interactions between clouds and their environment, with little consideration of the effects of shear. In this study, we use a combination of high-resolution (10 m) large-eddy simulation (LES), a direct method for calculating entrainment, and a 3-D cloud identification algorithm to explore cloud-environment interactions for various wind profiles. In particular, we focus on the composite behavior of vertical velocity, water vapor mixing ratios, entrainment, and vorticity under three different flow scenarios taken from two extensively studied and well-constrained case studies (Barbados Oceanographic and Meteorological EX-periment (BOMEX) and Rain in Cumulus over the Ocean (RICO)).