Extended Abstract (148K)15.9
The influence of large-scale soil moisture heterogeneity on wetting and drying planetary boundary layers
Edward G. Patton, NCAR, Boulder, CO; and P. P. Sullivan and C. H. Moeng
The majority of large-eddy simulation (LES) studies of the planetary boundary layer (PBL) decouple the land surface and the atmosphere by adopting constant surface boundary conditions. To investigate the temporal and spatial interaction between the soil surface and the overlying atmosphere, the NOAH LSM (NCEP/OSU/Air Force/Office of Hydrology Land Surface Model) has been coupled with the NCAR LES. The simulations to be discussed will involve horizontal heterogeneity with scales up to tens of kilometers while retaining sufficient horizontal resolution (~50m) to capture the essential PBL physics. Our investigation focuses on large-scale horizontal heterogeneity in soil moisture and it's influence on wetting and drying PBLs. Large-scale heterogeneity is shown to generate organized motions that alters PBL statistics. As an example, entrainment rates are shown to be dependent on the scale of the heterogeneity.
Session 15, Boundary Layers over Heterogeneous Surfaces
Friday, 19 July 2002, 8:30 AM-12:15 PM
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