Modeling interactions of aircraft emissions with global and regional atmospheric chemistry and climate

Aircraft engines emit a variety of chemical compounds that affect atmospheric chemistry and climate. In the research presented here, we have addressed three different issues related to aircraft emissions. The first phase of the research has two parts. In the first part, we have analyzed the effects of potential fleets of aircraft on atmospheric ozone concentrations. We have used a zonally-averaged two-dimensional chemical-transport model to parametrically evaluate the full envelop of effects from possible fleets of subsonic or near supersonic aircraft, that would fly extensively in the upper troposphere and lower stratosphere (UTLS) region. The maximum effect from the new set of parametric studies on Northern Hemisphere total column ozone change is seen to be -0.82%, implying that, for certain designs and potential use, fleets of aircraft could raise concerns about global ozone depletion. In the second part, our narrowband radiative transfer model is used to investigate how aircraft emissions impact on the net radiative forcing driving changes in climate. A series of sensitivity studies are performed and the results show that there should be little concern about climate effects due to the projected fleets resulting from effects on atmospheric water vapor and ozone.; In the last phase, we have focused on analyzing the impact of aircraft flights from Chicago O'Hare and Midway Airports on the regional air quality of the region using the Community Multiscale Air Quality Model (CMAQ) system. Our results suggest that the aircraft traffic at the Chicago O'Hare and Midway Airports do not contribute significantly to ground level ozone pollution in the Chicago area, and are much smaller than the effects due to other emissions such as those from vehicular traffic.