| Popis: |
The projected increase in global air traffic raises concerns about the potential impact aviation emissions have on climate and air quality. Previous studies have shown that aircraft non-landing and take-off (non-LTO) emissions (emitted above 1 km) can affect surface air quality by increasing concentrations of ozone (O3) and fine particles (PM2.5). Here, we examine the global impacts of aviation non-LTO emissions on surface air quality for present day and mid-century (2050) using the Community Atmosphere Model with Chemistry, version 5 (CAM5). An important update in CAM5 over previous versions is the modal aerosol module (MAM), which provides a more accurate aerosol representation. Additionally we evaluate of the aviation impact at mid-century with two fuel scenarios, a fossil fuel (SC1) and a biofuel (Alt). Monthly-mean results from the present day simulations show a northern hemisphere (NH) mean surface O3 increase of 1.3 ppb (2.7% of the background) and a NH maximum surface PM2.5 increase of 1.4 μg/m3 in January. Mid-century simulations show slightly greater surface O3 increases (mean of 1.9 ppb (4.2%) for both scenarios) and greater PM2.5 increases (maximum of 3.5 μg/m3 for SC1 and 2.2 μg/m3 for Alt). While these perturbations do not significantly increase the frequency of extreme air quality events (increase is less than 1.5%), they do contribute to the background concentrations of O3 and PM2.5, making it easier for urban areas to surpass these standards. |
Full Text from ScienceDirect