Lessons Learned from the Bay Region Atmospheric Chemistry Experiment (BRACE) and Implications for Nitrogen Management of Tampa Bay
Citation:
Poor, N., L. Cross, AND R. Dennis. Lessons Learned from the Bay Region Atmospheric Chemistry Experiment (BRACE) and Implications for Nitrogen Management of Tampa Bay. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 70(5):75-83, (2013).
Impact/Purpose:
The National Exposure Research Laboratory′s (NERL′s) Atmospheric Modeling and Analysis Division (AMAD) conducts research in support of EPA′s mission to protect human health and the environment. AMAD′s research program is engaged in developing and evaluating predictive atmospheric models on all spatial and temporal scales for forecasting the Nation′s air quality and for assessing changes in air quality and air pollutant exposures, as affected by changes in ecosystem management and regulatory decisions. AMAD is responsible for providing a sound scientific and technical basis for regulatory policies based on air quality models to improve ambient air quality. The models developed by AMAD are being used by EPA, NOAA, and the air pollution community in understanding and forecasting not only the magnitude of the air pollution problem, but also in developing emission control policies and regulations for air quality improvements. --------------------------------------------------------------------------------
Description:
Results from air quality modeling and field measurements made as part of the Bay Region Atmospheric Chemistry Experiment (BRACE) along with related scientific literature were reviewed to provide an improved estimate of atmospheric reactive nitrogen (N) deposition to Tampa Bay, to apportion atmospheric N between local and remote sources, and to assess the impact of regulatory drivers on N deposition to Tampa Bay. Simulations using the Community Multiscale Air Quality model v4.4 modified with the University of California Davis aerosol module (CMAQ-UCD) provided a framework for this review. For 2002, CMAQ-UCD modeled atmospheric loading rates were 6,910 metric tons N to the land surface of the watershed and 548 metric tons N to bay surface of the watershed, respectively. If an 18% transfer rate of atmospherically-deposited N from watershed to bay is assumed, then the corresponding atmospheric loading to Tampa Bay was 1,790 metric tons N or 57 % of the total N loading to the bay. From CMAQ-UCD modeling, oxidized N sources both within and outside Tampa Bay’s watershed were important contributors to atmospheric N loading to the bay. Within the watershed, oxidized N emissions from mobile sources had a disproportionally larger impact than did power plant sources on atmospheric N loading. Predicted decreases in atmospheric N deposition to Tampa Bay by 2010 due to regulatory drivers were significant, and plausibly evident in recent declines in ambient air NOx concentrations in urban Tampa and St. Petersburg.
URLs/Downloads:
AE_POOR_CROSS_DENNIS_091312 DATE MODIFIED 020713.PDF (PDF, NA pp, 1436.832 KB, about PDF)Atmospheric Environment
