This is a past event.

Annmarie G. Carlton
Rutgers University

Liquid water is the most abundant condensed phase species in the atmosphere, 2-3 times aerosol dry mass and clouds cover roughly 60% of the Earth's surface at a given time. Muliphase and heterogeneous chemistry involving atmospheric waters is associated with critical air quality and climate issues, such as the deleterious ecosystem effects of acid deposition and stratospheric ozone depletion. Yet chemical mechanisms employed in atmospheric photochemical transport models largely neglect the impact of the aqueous medium, in particular for organic species. This hinders development of effective strategies for air quality management and climate mitigation because important processes and feedbacks are missing from model predictions. A solubility index is developed to describe the potential of organic gases to partition to liquid water in a common framework that takes into account spatial and temporal variability among organic gases and particle phase water. This framework contributes to the indication that anthropogenic pollution enhances formation of secondary organic aerosol (SOA) from biogenic VOC precursors, and provides mechanistic insight to an additional anthropogenic influence, namely the ability of sulfur pollution to increase the amount of particle phase liquid water in the atmosphere. The solubility index and partitioning potential may resolve a key discrepancy whereby biogenic SOA mass concentrations in the southeast U.S., where anthropogenic pollution and biogenic emissions routinely mix and particle phase liquid water concentrations are predicted to be high, are much greater than biogenic SOA mass concentrations in the Amazon.

Host Lynn Mazzoleni