Monday, 15 January 2007: 12:00 AM
Coupling of CB05 gas-phase chemical mechanism with MADRID aerosol module in WRF/Chem
212A (Henry B. Gonzalez Convention Center)
The gas-phase chemical mechanism and aerosol module are two major components in three-dimensional air quality models that are designed to simulate air pollutants such as sulfur dioxide (SO2), oxides of nitrogen (NOx), ozone (O3), and fine particulate matter (PM2.5). Currently, three gas-phase chemical mechanisms and three aerosol modules exist in the North Carolina State University's version of the Weather Research and Forecast/Chemistry (WRF/Chem) model version 2.1.2. The gas-phase chemical mechanisms are the second generation Regional Acid Deposition Model Mechanism (RADM2), the Regional Atmospheric Chemistry Mechanism (RACM), and the Carbon-Bond Mechanism version Z (CBM-Z). The aerosol modules include the Modal Aerosol Dynamics model for Europe (MADE) with the Secondary Organic Aerosol Model (MADE-SORGAM), the Model for Simulating Aerosol Interactions and Chemistry (MOSAIC), and the Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID). An updated version of the Carbon Bond Mechanism IV (CBM-IV), the 2005 version of CBM (CB05) has recently been incorporated into the WRF/Chem model in-house. While MADRID has been coupled with CBM-Z in WRF/Chem, CB05 will be coupled with MADRID in WRF/Chem in this study. A one-month simulation (July 2001) over the continental U.S. domain with a horizontal grid spacing of 36-km will be used to test the performance of WRF/Chem-MADRID-CB05. Several gas-phase pollutants (e.g., SO2, NOx, and O3), PM2.5, and PM2.5 compositions will be evaluated with observations from several national monitoring networks. Then, the comparisons of model simulations with the same PM module (i.e., MADRID) but different gas-phase mechanisms (e.g., CB05 and CBM-Z) or those with the same gas-phase mechanism (i.e., CB05) but with different aerosol modules (e.g., MADE-SORGAM, MOSAIC, or MADRID)) will be conducted to understand the differences in the PM simulations by different coupling of gas-phase mechanism with aerosol modules in WRF/Chem.