Airport related emissions and impacts on air quality: Application to the Atlanta International Airport

In the last decade, air traffic has increased dramatically with a significant increase in emissions. Our goal is to quantify the impact of aircraft emissions on regional air quality, especially in regards to PM _2.5 and ozone. Here the focus is on Hartsfield-Jackson Atlanta International Airport which is the busiest airport in the world based on passenger traffic. First, aircraft PM_2.5 emissions are estimated based on the Smoke Number (SN) by using the "first order" method. The Emissions and Dispersion Modeling System (EDMS) is used for gaseous species. PM_2.5 emissions are estimated once based on the characteristic SN and a second time using the mode-specific SN. Further, aircraft emissions are processed in two ways: (1) allocating the emissions at the airport itself, and (2) by accounting for flight paths, mode, and plume rise. When the more conservative emission estimates are used (i.e, the characteristic SN estimates allocated to the airport), results suggest that Hartsfield-Jackson airport can have a maximum impact of 56 ppb on ozone with a 5 ppb average impact over most of the Atlanta area. PM_2.5 impacts are also estimated to be quite large with a maximum local impact of 25 μg m^-3. Impacts over most of the Atlanta area are less than 4 μg m^-3. The second set of emissions with detailed spatial allocation leads to a less intense ozone impact with a maximum of 20 ppb and an average of less than 1 ppb. PM_2.5 impacts, in this case, are about 1 μg m^-3 within a radius of 16 km around the airport. The difference in these two results shows the importance of how aircraft emissions are treated. The impacts on ozone and PM_2.5 of ground support equipment at the airport are smaller compared to the aircraft impacts, with a maximum impact of 2 ppb for ozone and 9 μg m^-3 for PM_2.5.