Need for Improved Monitoring of Spatial and Temporal Trends of Reduced Nitrogen
Data in Figure 1 are from publicly available databases including county-level ammonia (NH3) emissions from the US EPA National Emissions Inventory (https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-data), ambient ammonium (NH4+) aerosol concentrations from the US EPA Clean Air Status …