Long-Term Trends in Sulfur and Reactive Nitrogen Deposition Across the Northern Hemisphere and United States

Abstract

We model the changes in wet and dry deposition amounts of reactive nitrogen and sulfur over the 1990–2010 period using the WRF-CMAQ modeling system. WRF-CMAQ simulations for this 21-year period were conducted over a domain covering the northern hemisphere using a horizontal resolution of 108 km and a nested domain over the contiguous U.S. using a grid of 36 km resolution. The impacts of contrasting changes in emission patterns across the Northern Hemisphere, i.e., reductions in North America and Europe vs. increases across regions in Asia, on changing deposition amounts over terrestrial and aquatic ecosystems in these regions is analyzed.