CAREER: The Marine Cloud-Topped Planetary Boundary Layer (PBL) and Large-Scale Circulations

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

The planetary boundary layer (PBL) is the lowest layer of the atmosphere - the layer in immediate contact with the earth's surface - through which heat, momentum, moisture, gaseous species, and aerosol particles are transported between the free atmosphere and the surface. It is no surprise that processes in the PBL have a bearing not only on local phenomena such as air pollution, wind, and precipitation, but also on the climate itself through interactions with larger scale processes. The research component of this CAREER award focuses on two questions: (1) How does the PBL interact with the large-scale, thermally driven, tropical atmospheric circulation? (2) How does precipitation from clouds that form in the PBL modify the dynamics of this interaction? The approach to each question is through numerical modeling. For the first, a General Circulation Model (GCM) is modified to represent more accurately the physical processes in the PBL. For the second, large eddy simulations (LES) are employed to determine how the vertical structure of the PBL is affected by precipitation. The educational component of the work consists of developing an upper-level undergraduate course on the interaction of large scale atmospheric flow with the PBL and establishing a climate simulation laboratory. The results of the effort will be improved climate simulation and better opportunities for students to be trained in the numerical modeling of climate.