An Investigation of the Impacts of Aviation Emissions on Current and Future Fine Particulate Matter in the U.S.

The impacts of aviation emissions on current and future year fine particulate matter (PM2.5) were investigated using the Community Multiscale Air Quality model, accounting for aviation emissions from 99 airports and below 10,000 ft during the landing and takeoff (LTO) cycle. Results indicated that current year aviation emissions increased average PM2.5 concentrations by 0.0032 μg m-3 (0.05%) in the continental U.S. while projected 2025 aviation emissions increased average PM2.5 by 0.0116 μg m-3 (0.21%). Nitrate aerosol was the largest contributor to the increase in PM2.5 concentrations due to aircraft emissions, particularly in the future year. Using an indicator of inorganic PM2.5 change, we attributed nitrate aerosol contributions to excess free ammonia and higher aircraft emissions of NOx (which when converted to HNO3 forms ammonium nitrate aerosol) than SO2 (a precursor of sulfate aerosol)