A Global-Scale Multi-resolution Study of Surface Air Quality Impacts from Commercial Aircraft Emissions

The Model for Ozone and Related chemical Tracers, version 4 (MOZART-4), an offline global-scale chemistry-transport model was applied to assess air quality impacts focusing on ground-level O-3 and PM2.5 due to full-flight (during cruise (CRZ) mode, and landing/take-off (LTO) activities) commercial aircraft emissions. MOZART-4 was run at two different horizontal resolutions-the first at 2.4 x 1.9 degrees, which is typical of most global-scale models, and a second at a much finer resolution of 0.67 x 0.5 degrees, and using 56 and 72 vertical layers, respectively, for the year 2005. Overall, emissions during LTO modes cause higher impacts on surface PM2.5 concentrations than CRZ. Full flight impact on surface PM2.5 concentration was similar to 0.018-0.023 mu g/m(3) which is in the range of estimates reported by previous studies. However, we saw that CRZ mode had higher contribution on surface O-3 than from LTO; totally, aircraft attributed global annual average surface O-3 was similar to 2.0-2.4 ppbv, higher than previously reported values.