Regional Impact Of The Ohio River Valley on Boundary-Layer SO4 Concentrations: Results From INTEX-NA
Abstract
In the summer of 2004, airborne measurements of fine inorganic aerosol composition were made aboard the NASA DC-8 as part of the INTEX-NA study. PM1 was measured with a PILS-IC system over the continental United States and parts of Canada. Sulfate was the dominant species measured, with the highest concentrations observed at low altitudes (below 2 km). The Ohio River Valley (ORV) accounts for approximately 20 to 25 percent of US point-source sulfur dioxide emissions. As such, regions downwind of the ORV it can experience significant air quality effects due to highly concentrated upwind emissions. Using back trajectory models and aircraft measurements of aerosol sulfate and sulfur dioxide, an analysis has been performed to assess the ORV's influence on fine particulate sulfate measured over the eastern US and Canada during INTEX-NA. Our analysis suggests that there was long-range transport of pollutants from the ORV over distances greater than 1000 km and transport events were observed over much of the sampling domain. The highest sulfate concentrations sampled in the study were apparently influenced by the ORV. On average, the sulfate concentration in ORV-influenced air masses was a factor of three higher than in air masses that had no ORV influence. Two back trajectory models, the NOAA HYSPLIT model and the FLEXPART model, were employed to increase the confidence and utility of the analysis performed. In general, agreement between the two models was excellent.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2005
- Bibcode:
- 2005AGUFM.A31A0812H
- Keywords:
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- 0305 Aerosols and particles (0345;
- 4801;
- 4906);
- 0345 Pollution: urban and regional (0305;
- 0478;
- 4251)