Atmospheric Organic Aerosol-Water Interactions

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

Organic compounds represent on average 30-70% of the fine aerosol mass in both polluted and clean areas. They contribute to the direct and indirect aerosol radiative forcing of climate via their own optical properties and their effects on clouds and precipitation. They are also pose significant environmental risks via visibility degradation, and health effects through the air that we breathe. The chemical complexity of the organic aerosol (OA) fraction of aerosols makes the representation, modeling and understanding of their properties notably challenging. A range of studies to be investigated here covers a range of topics, including: * the ability of organic compounds to promote (or inhibit) the growth of inorganic particulate matter with increasing relative humidity (RH), * the effect of RH on the partitioning of semi-volatile OA components between the gas and particulate phases, * the water solubility distribution of ambient OA, * and the systematic estimation of Henry's law constants of semi-volatile organic vapors. The study will involve a combination of laboratory experiments, field measurements, and mathematical modeling, with a goal of incorporating the mathematical representation of OA components into chemical transport models, designed to track and forecast OA distribution .