Comparison of Meteorology from a Weather-Chemistry Forecast Model with Observations During the TEXAQS-2000 Field Study
Abstract
Meteorological data collected by the NCAR Electra aircraft, wind profilers, and balloon-sondes are used in this study to assess the NOAA Forecast System Lab's air quality forecast model (MM5-CHEM). This model is a modified version of the Penn State/NCAR nonhydrostatic mesoscale model (MM5, version 3) that includes the on-line calculation of gas-phase ozone photochemistry using the Regional Acid Deposition Model (RADM, version 2) mechanism. The model incorporates multiple one-way nested meshes of 60, 15, 5, and 1.67 km centered over the Houston-Galveston region. The forecasts from this model were available in real-time during the TEXAQS 2000 field study. However, post analysis revealed significant and persistent biases in wind direction resulting in the displacement of forecast pollution plumes observed during aircraft transects downwind of various point and urban sources. This study diagnostically evaluates several aspects of the model formulation and physics by comparing model results from modifications made to the original formulation for the August 25 to August 30, 2000 time period. These include changes made to the boundary layer transport parameterization, the specification of ground temperature, and the meteorological data sets used for field initialization. The effects these changes have on predicted plume location and ozone formation are also included in the analysis.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.A12D0198B
- Keywords:
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- 0345 Pollution: urban and regional (0305);
- 0365 Troposphere: composition and chemistry;
- 0368 Troposphere: constituent transport and chemistry