Formation, Transformation, and Climate Impacts of Atmospheric Aerosols

Aerosols or particular matter (PM) profoundly impact the Earth-atmosphere system in several distinct ways. Globally, aerosols influence the Earth's energy balance, directly by scattering and absorbing the solar radiation and indirectly by modifying cloud formation and altering the lifetime and albedo of clouds. The lack of understanding of the aerosol direct and indirect radiative forcings currently corresponds to the largest uncertainty in climate predictions. On the regional and local scales, aerosols represent a major contributor to air pollution. Adverse effects of fine PM on human health constitute the most important element in formulating the National Ambient Air Quality Standards, and increasing evidence has implicated fine PM in exacerbation of existing health symptoms and the development of serious chronic diseases. This presentation will discuss our recent experimental, field, and modeling studies on formation, transformation, and climate impacts of aerosols, focusing on new particle formation and aging of soot particles.