The difference between thin and thick fair-weather shallow cumulus inferred from ARM observations over the Southern Great Plains
Poster PDF
Authors
Stephen Klein — Lawrence Livermore National Laboratory
Yunyan Zhang — Lawrence Livermore National Laboratory
Category
Cloud Properties
Description
During summertime over large areas at the U.S. Southern Great Plains (SGP), fair-weather shallow cumulus clouds tend to occur frequently. The diurnal evolution of these clouds is closely related to surface fluxes and atmospheric boundary layer development. Based on 13 years of observations by millimeter-wavelength cloud radar at the ARM Central Facility and GOES satellite images, we carefully select and categorize days with "thin" and "thick" shallow cumulus clouds to study forced and active fair-weather shallow cumulus. Composite forcings are also constructed to drive the large-eddy simulation and single-column model cases to test models with observations. By so doing, we address (1) the differences in cloud properties and their radiative impacts between days with “thin” versus “thick” clouds and (2) the differences in environmental conditions between these days and what controls the vertical extent of shallow cumuli.
