UMD AOSC Seminar
"Blue Collar" Science and The Maryland State Implementation Plan for Air Quality
Dr. Jeffrey W. Stehr
University of Maryland
Department of Atmospheric and Oceanic Science
In the U.S., the EPA sets environmental standards for six air pollutants, among them ozone. The air chemistry group has assisted the State of Maryland with plans to comply with those standards, with the most recent plans submitted in 2007 and 2008. We used our extensive library of past measurements, several modeling runs, and some innovative comparisons between model and data to determine that the air quality model of choice was under-representing the forecast changes in ozone. In particular, the model failed to capture diurnal patterns in ozone and changes in ozone due to pollutant emission changes. After seeing this, we made adjustments to the predicted concentrations to account for the model’s apparent lack of sensitivity, much as one makes adjustments to predictions from a meteorological forecast model using the MOS (Model Output Statistics) approach. The resulting adjustment to the prediction took Maryland from being barely outside of attaining the standard to being well inside attainment. Now that the year being forecast (2009) has passed, it’s fair to ask: what happened? We found a mixture of results, including one surprising monitoring site, and were happy that we probably got a little lucky as well. Along the way, we also found some interesting science and our results point to some intriguing areas for further investigation.
February 11, 2010, Thurday