The Impact of Land Surface Inhomogeneity on the Diurnal Cycle of Shallow Convection around SGP
Authors
Heng Xiao — Pacific Northwest National Laboratory
Larry Berg — Pacific Northwest National Laboratory
Maoyi Huang — National Oceanic and Atmospheric Administration (NOAA)
Category
Boundary layer structure, including land-atmosphere interactions and turbulence
Description
We employ the Weather Research and Forecast (WRF) model in its large-eddy simulation (LES) mode to study the impact of land surface inhomogeneity on the formation and evolution of shallow convection around the Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) mega site. The goal is to investigate how land surface inhomogeneity features that are similar to those present around SGP (in terms of size and impact on surface fluxes magnitude and partitioning) and at scales much smaller than the typical climate model grid size, affect the surface energy exchange and influence the development of planetary boundary layer and shallow convection. The surface fluxes for each land-use/land cover type are either prescribed based on simulations from the Community Land Model with its parameters constrained by observations from the ARM ECOR and EBBR systems or calculated by CLM online. The inhomogeneity features impact the organization and evolution of shallow convection differently under varying atmospheric conditions, e.g., low-level stability, overall surface forcing strength and Bowen ratio, wind speed and shear, as shown using realistic case setups extracted from ARM observations.
