Water Resources Research Act Program

Details for Project ID 2015LA101B

Atmospheric deposition of nitrogen and sulfur to Louisiana water bodies

Institute: Louisiana
Year Established: 2015 Start Date: 2015-03-01 End Date: 2016-02-28
Total Federal Funds: $19,680 Total Non-Federal Funds: $39,503

Principal Investigators: Hongliang Zhang, Hongliang Zhang

Abstract: Sulfur and nitrogen contained air pollutants are directly emitted from anthropogenic and biogenic sources or secondarily formed through complex reactions using the atmosphere as a potent oxidizing medium. The result of atmospheric processes is the existence of sulfur and nitrogen pollutants in gas phase, aerosol phase, and aqueous phase. The ultimate methods that remove sulfur and nitrogen species from atmosphere are wet deposition and dry deposition. Although deposition of these pollutants reduces their concentrations in atmosphere, it leads to increase of sulfur and nitrogen fluxes to the surface. Atmospheric deposition of sulfur and nitrogen can lead to acidification of surface water bodies (lakes, rivers, and coasts) (Heard et al., 2014) and subsequent damage to aquatic ecosystems as well as damage to forests and vegetation (Benedict et al., 2013; Bytnerowicz et al., 2007; Vinebrooke et al., 2014) since major of sulfur and nitrogen species are in acidic forms. Also, as an essential nutrient element for all living, deposition of nitrogen originated from anthropogenic sources causes nutrient imbalances of ecosystems, contributing to long-term eutrophication, increase of weedy plant species, and loss of native species. (Bergstr and Jansson, 2006). Efforts have been made to understand and control atmospheric deposition of sulfur and nitrogen in US and worldwide. The National Atmospheric Deposition Program (NADP) (Lamb and Bowersox, 2000) was initiated in 1977 to measure atmospheric deposition and the Clean Air Status and Trends Network (CASTNET) (Baumgardner et al., 2002) was established in 1991 to assess the trends in acidic deposition. Total sulfur deposition in East US declined 46% and nitrogen deposition decreased by 26% from 1990 through 2009 (MACTEC Engineering and Consulting, 2011). Thus, the objective of this project is to 1) understand the forms and quantities of sulfur and nitrogen deposition from wet and dry processes in Louisiana; 2) show the spatial and temporal variations of sulfur and nitrogen fluxes; and 3) quantify the contributions to sulfur and nitrogen deposition from different source sectors or source regions.