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DEVELOPMENT OF A LAND-SURFACE MODEL PART I: APPLICATION IN A MESOSCALE METEOROLOGY MODEL
Citation:
Xiu, A. AND J E. Pleim. DEVELOPMENT OF A LAND-SURFACE MODEL PART I: APPLICATION IN A MESOSCALE METEOROLOGY MODEL. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY 40(2):192-209, (2001).
Impact/Purpose:
This task objective is the development and improvement of state-of-the-science meteorology models and contributing process parameterizations for use in advanced air quality simulation model systems such as the Community Multi-scale Air Quality (CMAQ) modeling system and for other modeling studies and situations involving transport and dispersion of pollutants. Components of this work include: (a) improved meteorological and transport modeling, (b) improved meteorological modeling physics, (c) physical modeling of flows- building wakes, complex terrain, urban canyons, (d) modeling of transport and dispersion of specialized situations and (e) develop AERMOD (AMS/EPA Regulatory MODel).
Description:
Parameterization of land-surface processes and consideration of surface inhomogeneities are very important to mesoscale meteorological modeling applications, especially those that provide information for air quality modeling. To provide crucial, reliable information on the diurnal evolution of the planetary boundary layer (PBL) and its dynamic characteristics, it is necessary in a mesoscale model to include a land surface parameterization that simulates the essential physics processes and is computationally efficient.
A land surface model is developed and implemented in the Fifth Generation Penn State/NCAR Mesoscale Model (MM5) to enable MM5 to respond to changing soil moisture and vegetation conditions. This land surface model includes explicit soil moisture, which is based on the Interaction Soil Biosphere Atmosphere (ISBA) model and three pathways for evaporation including soil evaporation, canopy evaporation, and vegetative evapotranspiration. The stomatal conductance, leaf to canopy scaling, and surface moisture parameterizations are newly developed based on a variety of sources in the current literature. Also, a processing procedure for gridding soil and vegetation parameters and simulating seasonal growth has been developed. MM5 with the land surface model is tested and evaluated against observations and the "standard" MM5, which uses a simple surface moisture availability scheme to estimate the soil wetness then the latent heat flux, for two cases from the First International Satellite Land Surface Climatology Project Field Experiment (FIFE). The evaluation analysis focuses primarily on surface fluxes of heat and moisture, near surface temperature, soil temperature, PBL height, and vertical temperature profiles. A subsequent article will describe extensions of this model to simulate chemical dry deposition.
The U.S. Environmental Protection Agency through its Office of Research and Development funded the research described here under cooperative agreement CR-823628 to the MCNC-Environmental Programs. It has been subjected to agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.