HR: 0800h
AN: A51B-0345    [Abstracts]
TI: Comparisons of Observed and Simulated Atmospheric Boundary Layer Diurnal Cycle in California's Central Valley for the Summer of 2000
AU: Michelson, S
EM: Sara.A.Michelson@noaa.gov
AF: NOAA/ESRL/PSD and CIRES/University of Colorado, 325 Broadway Mail Stop: PSD3, Boulder, CO 80305,
AU: Djalalova, I
EM: Irina.V.Djalalova@noaa.gov
AF: NOAA/ESRL/PSD and CIRES/University of Colorado, 325 Broadway Mail Stop: PSD3, Boulder, CO 80305,
AU: * Bao, J
EM: Jian-Wen.Bao@noaa.gov
AF: NOAA/ESRL/PSD, 325 Broadway Mail Stop: PSD3, Boulder, CO 80305,
AB: The diurnal cycle of the atmospheric boundary layer (ABL) in California's Central Valley is controlled by meteorological processes on various scales. Thus, errors in model simulated ABL, as revealed by comparisons of the simulation with observations, indicate that there are errors in those meteorological processes. In this study, the 5-day averaged ABL diurnal evolution simulated by the NCAR/Penn State community mesoscale model (MM5) is systematically validated and evaluated using the observations from the Central California Ozone Study (CCOS) 2000 field experiment. The model simulated ABL winds and thermal structure, as well as the corresponding diagnostic quantities such as divergence and vorticity, are compared with the observational counterparts. It is found that the ABL mixing parameterization in MM5 can simulate the ABL structure and dynamics in California's Central Valley reasonably well under clear sky when the large-scale, upper-level forcing and surface characteristics are specified correctly. Our evaluation indicates that the errors in the model simulations of ABL structure and dynamics are most often caused by errors in the model's upper level synoptic scale flow and uncertainties in the surface characteristics.
DE: 3307 Boundary layer processes
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
DE: 3329 Mesoscale meteorology
DE: 3355 Regional modeling
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting