Numerical Model Studies of Underlying Surface Effects on Cumulus-Scale Atmospheric Convection

摘要

The report presents the results of the first stages of an investigation into the effects of surface characteristics on cumulus scale convection. The basic formulation of moist convection generally, the parameterized boundary layer and the solution scheme, are presented. The experimental design that has been developed to respond to two basic aspects of the investigation of the surface effects on convection is detailed. Some preliminary results are discussed for two runs, one having a stable boundary layer and one an unstable boundary layer; both above smooth (z(0) = 1 cm), relatively dry ground. These results are compared to a bench mark simulation having a closed lower boundary with a slip condition. Finally, a comparative investigation of several finite-difference schemes covers both explicit and implicit schemes as well as several numerical experiments using a dry-convection model with no boundary layer. (Author)