Context of aerosol chemistry over the Southeast United States

Abstract:

Aerosols over the Southeast United States consist mostly of organics and sulfate with important contributions from nitrate, dust, and elemental carbon. Ground-based networks such as IMPROVE show seasonal patterns and trends in these species. A summer maximum caused by sulfate has decreased in recent years. Black carbon has declined but the decrease in sulfate has had a larger radiative effect. Satellite data such as MISR augment show the spatial pattern of this summer decrease. The large trend in sulfate but not ammonium has led to a dramatic change in aerosol neutralization. This has consequences for the formation of nitrates and organosulfates.