HR: 0800h
AN: H31E-0694    [Abstracts]
TI: Influence of surface heterogeneity on a realistic convective boundary layer
AU: * Huang, H
EM: hyhuang@ucla.edu
AF: University of California, Los Angeles, 5732D Boelter Hall, Department of Civil and Environmental Engineering, UCLA, Los Angeles, CA 90095, United States
AU: Margulis, S
EM: margulis@seas.ucla.edu
AF: University of California, Los Angeles, 5732D Boelter Hall, Department of Civil and Environmental Engineering, UCLA, Los Angeles, CA 90095, United States
AB: Turbulent interactions of momentum and scalars within the convective boundary layer (CBL) over a heterogeneous surface have strong influence on both local flow properties and the regional weather and climate. Based on results of simulations over artificially idealized surface conditions (surface temperature, fluxes, roughness height, etc.), many studies have been performed to build our understanding of influence of surface heterogeneity by analyzing some statistics of characteristic properties in the atmosphere boundary layer. This research attempts to further our understanding by using realistic heterogeneous surface flux fields obtained from the Soil-Moisture Atmosphere Coupling Experiment 2002 (SMACEX) as boundary conditions in a Large-Eddy Simulation (LES). A set of realizations exactly replicating the mean and covariance of surface characteristics (relative to the actual fields at SMACEX) are used in the LES as boundary conditions. Specifically, two parts of analysis are discussed in this study: 1) the characteristic statistics of CBL properties (momentum, scalars, fluxes, variance, etc.); and 2) vertical scales of the CBL (momentum/scalar blending heights, internal boundary layer, convective scaling, etc.). Results from this study not only illustrate the influence of surface heterogeneity on a realistic CBL structure and statistics, but also offer a possibility to develop better parameterizations of surface characteristics used in regional climate models in the future.
DE: 1840 Hydrometeorology
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
DE: 3379 Turbulence (4490)
SC: Hydrology [H]
MN: 2007 Fall Meeting