Simulations Of Atmospheric Flows In The Boundary Layer Over Inhomogeneous Surface Conditions.

摘要

LONG TERM GOALS. The goal of this project is to improve the description and prediction of resolvable and subgrid-scale atmospheric fields over inhomogeneous surfaces and to develop an integrated modeling system for weather phenomena and dispersion effects on a variety of spatial and temporal scales. OBJECTIVES. Specific objectives include: 1) test the nonlocal mixing parameterization using a Large-Eddy Simulation (LES) model and incorporate it into a mesoscale model, 2) further develop the Lagrangian random particle dispersion model and test its turbulence parameterization, and 3) further develop a system for evaluating atmospheric models using tracer measurements. This work is supported by the Office of Naval Research, Marine Meteorology and Atmospheric Effects. APPROACH. We have tested the parameterization of nonlocal mixing by using a fully compressible cloud-resolving model (Koracin et al. 1998a) and a LES (Moeng (1984), and Andren (1995)). The nonlocal parameterization was incorporated into the higher-order turbulence-closure mesoscale model (Tjernstr m and Koracin 1995). The Lagrangian random particle (LAP) model (Isakov 1998, Koracin et al. 1998b) was further developed with respect to its treatment of the transport and dispersion of quasi-inert toxic gas (Koracin et al. 1999a). The "Tracer Potential" method (Koracin et al. 1998e, 1998f, 1998c, 1999b, and 1999c) was compared with a statistical method which takes into account the spatial distribution of simulated and measured concentration patterns.