Aerosol event over North America: contours

This sequence shows an extreme aerosol optical depth event that occurred August 17-19, 2003 as simulated with the WRF-Chem model. Each frame shows one hour. The left panel shows the event when simulated with emissions as of 2005, the right when emissions are scaled to 2015 values. As shown the event is drastically weakened when the emission control measures are implemented, causing improvements in air quality and a reduction of aerosol-induced surface cooling. This latter effect means aerosols are offsetting less of the greenhouse gas induced warming at the surface. Simulation details are reported in: Guo Y., Crippa P., Thota A. and Pryor S.C.: Extreme aerosol events over eastern North America. Part 2: Responses to changing emissions. Journal of Geophysical Research: Atmospheres (2020JD033759). Guo Y., Crippa P., Thota A. and Pryor S.C.: Extreme aerosol events over eastern North America. Part 1: Characterizing and simulating historical events. Journal of Geophysical Research: Atmospheres (2020JD033758).