Implication of Climate Change on Deposition of Sulfur and Nitrogen Compounds in U.S

Sulfur and nitrogen emissions can lead to a variety of adverse environmental consequences, including increased particulate matter, acid rain and eutrophication. On the other hand, the increases in particulate matter may decrease warming on a local scale. In this work, how future climate change may potentially affect the deposition of sulfur and nitrogen compounds over the entire continental U.S. is studied. MM5/SMOKE/CMAQ is used to assess how regional air quality and deposition vary between the years 2001 and 2050, as well as the summers of 2049 and 2051, and how those results depend upon modeled climatic changes. Regional-scale meteorology is derived from downscaling outputs generated by a global climate model using MM5 modeling system. Results obtained from the simulation results are determined for the future years of 2049, 2050 and 2051. Deposition of sulfur and nitrogen compounds for summer episodes of 2049 and 2051 and the whole year of 2050 are simulated. The simulations for summer episodes of 2000 and 2002 and the whole year of 2001 are also done for the comparison between historic and future years. In the preliminary simulation results, we have found an increase of mean temperature and changes in other meteorological conditions including precipitation in the future. Therefore, the potential changes of precipitation as well as concentrations of sulfur and nitrogen compounds are very likely to impact the amount and distribution of deposition throughout the U.S. in the future. In this study, the changes of precipitation and concentrations of sulfur and nitrogen compounds due to climate change are determined first. Then, the impacts of climate change on deposition of sulfur and nitrogen compounds are assessed quantitatively. The partitioning of sulfur and nitrogen compounds between wet and dry deposition is also investigated for both historic and future years in order to understand the potential change in deposition over the continental U.S.