Chemical Oxidation Reactions and Hydrophobic-to-Hydrophilic Aging of Atmospheric Organic Aerosol Particles

We are investigating the reactivity of organic aerosol particles, particularly their conversion from hydrophobic to hydrophilic characteristics during processing by atmospheric oxidants such as ozone. Once hygroscopic, organic particles alter cloud properties (e.g., duration and brightness) by serving as the nuclei for water condensation. Quantification of these effects is limited, however, because the compositions, morphologies, and reactivities of organic particles are poorly understood. Laboratory studies are essential for understanding and quantifying complex particles and their chemical and physical processes. A key need is an elucidation of the chemical reactions between the organic particulate matter and gas-phase oxidants such as ozone. Our work is focused on ozone heterogeneous chemistry as a proxy for understanding the role of layer thickness in the chemical transformations of surface and interior layers of complex, multicomponent particles.

We are grateful for NSF (ATM 0215357; ATM0513463) and Camille and Henry Dreyfus Foundation (EP-00-003) support.

Publications