Particulate Matter Modeling

PM Data Analysis and Modeling

The U.S. EPA reduced the 24-hour average ambient standard for PM2.5 from 65 µg/m³ to 35 µg/m³ in 2006. In 2009, the EPA determined that the Bay Area does not meet the new standard and the Bay Area Air Quality Management District (BAAQMD) will be required to prepare a State Implementation Plan. The Bay Area meets the national annual average PM2.5 standard of 15 µg/m³.

To better understand PM2.5 formation in the Bay Area and prepare the State Implementation Plan, a number of data analysis and modeling projects are currently underway. These projects include:

• Classification of meteorological conditions conducive to observed elevated PM2.5 concentrations in the Bay Area
• Development and evaluation of an ammonia emissions inventory for the Bay Area. Ammonia is an important ingredient in the formation of secondary PM2.5.
• Meteorological modeling with the MM5 model to prepare inputs to PM modeling
• PM modeling using the CMAQ model for winter 2000-2001 and 2006-2007
• Statistical analysis for MM5 and CMAQ performance evaluation
• Simulating wintertime meteorology with the Weather Research and Forecasting Model.

Available reports and related documents: