Lake Spray Aerosol Emissions Alter Nitrogen Partitioning In The Great Lakes Region

We develop an improved, wind-driven lake spray aerosol (LSA) emissions parameterization that resolves particle size and size-independent chemical composition, and investigate the impact of these emissions on regional chemistry in the Great Lakes region. We conduct Weather Research and Forecasting model with online Chemistry simulations for November 2015, a time period with high LSA emissions. LSA particles emitted from the surface of the Great Lakes increase particulate NO3- by 37% over the Great Lakes and by 13% over land, primarily due to heterogeneous reactions between CaCO3 and HNO3. Cations emitted from lake spray affect the thermodynamic equilibrium, reducing particulate NH4+ by 16% over the Great Lakes and by 7% over the surrounding land. This also influences gas-phase species in the region, decreasing nitric acid by up to 32% over lakes. Overall, these simulations suggest that understanding LSA and its impact on other air pollutants is important for determining health and climate effects in the Great Lakes region.