Modeling the explicit chemistry of organic aerosols: Formation, removal, and comparison with observations

Poster PDF

Description

This new project will use observational data from three DOE-led field campaigns (GoAmazon, BBOP, and HI-SCALE) to evaluate and improve our hyper-explicit chemical model GECKO-A (the Generator of Chemistry and Kinetics of Organics in the Atmosphere), and specifically to evaluate its ability to predict the amounts and properties of organic aerosols (OA). Each campaign offers specific challenges and opportunities to evaluate and improve GECKO-A: GoAmazon sampled at the interface of regions dominated by biogenic or anthropogenic hydrocarbons, providing a contrast between chemical regimes that should be within the current predictive capability of GECKO-A. BBOP provides an opportunity to test and improve the chemistry of light-absorbing compounds, important to radiative forcing (brown carbon) and OA lifetimes (photolysis), with updates based on our Tropospheric Ultraviolet Visible model. HI-SCALE is expected to provide simultaneous measurements of organic molecules in air, aerosols, and cloud droplet residuals, and will be used to test our extension of GECKO-A to cloud chemistry. We anticipate that this will elucidate the formation of carboxylic acids, which observations show to be ubiquitous but are not fully explained, and the formation of OA particles when cloud droplets evaporate, which some (but not all) previous studies have suggested as major contributors to the global burden of organic aerosols. Successful improvements will be parameterized for implementation of a three-dimensional regional chemistry-transport model WRF-Chem and will be made available to the community.