Analysis of the Planetary Boundary Layer during the Baltimore – Washington, DC DISCOVER-AQ Field Campaign with Lidar Measurements and WRF Modeling

The planetary boundary layer (PBL) influences the development of weather systems and atmospheric composition by governing the depth to which surface fluxes of heat, moisture, and chemical species are vertically mixed, and the efficiency by which they are transported downwind. In this work, we analyze the PBL processes in the Baltimore - Washington, DC region during the DISCOVER-AQ field campaign that took place in July of 2011. The analysis uses MPLNET micro-pulse lidar (MPL), mini-MPL, airborne high spectral resolution lidar (HSRL), and CALIPSO satellite measurements along with complimentary surface and aircraft observations. To examine the physical processes influencing the PBL development WRF simulations with 1 km horizontal grid spacing and high vertical resolution near the ground are performed. A focus of the study is on the diurnal growth cycle of the PBL and the how the urban landscape and the proximity to the Chesapeake Bay and its associated bay breeze circulation affect the spatial variability of the PBL height throughout this cycle. In addition, we also present an analysis of how the WRF configuration, including the PBL scheme, urban canopy modeling options, and the sea surface temperature inputs affects the simulations of the PBL.