 |
NARSTO Workshop on Innovative Methods for Emission Inventory Development and Evaluation University of Texas, Austin October 14-17, 2003 |
 |
Poster 15: Use of DOAS Data at Two Monitoring Sites to Locate Benzene Emissions in Tampa, Florida
Carlo Amalitano, Noreen Poor
University of South Florida College of Public Health, Tampa, Florida 33612
Kerstin Kenty, Scott Campbell
University of South Florida, College of Engineering, Tampa, Florida 33620
Thomas Tamanini, Clemente Lopez
Environmental Protection Commission of Hillsborough County, Tampa, Florida 33605
In May 2002 as part of the Bay Regional Atmospheric Experiment (BRACE), continuous measurements of benzene were made at two monitoring sites in Tampa, Florida. These measurements were intended to help identify mobile source contributions to air pollutant levels at Sydney, a rural site ~5 km south of a major interstate highway, and at the eastern end of the Gandy Bridge, an urban site ~45 m from a state highway. At these fixed monitoring sites, the benzene plume was recognized with a data pattern that depended on the wind vector and the distance from the polluting location. Both forward and backward wind trajectory analyses indicate the source of benzene as petroleum tank farms located between the Sydney and Gandy Bridge sites, rather than motor vehicle emissions. Data analysis software was developed that given the associated meteorological data, points to the polluting sources with reasonable accuracy. The software is based on reverse analysis of the wind vector and to the known patterns of diffusion and dispersion of the pollutant. Distance of the pollution source is not measured directly, but it is statistically calculated from intersections of plumes during separate wind shifts and from the shape of the data (“angle of attack”) of the data stream. Longer data observations and more than one monitoring site provide greater confidence and precision, nevertheless, a single site and a single event may suffice to point to a specific location. This method can be applied to all other airborne pollutants.