CAREER: Interplay of Particle Phase State and Thermodynamic Mixing in Secondary Organic Aerosol Formation and Partitioning

University Of California-Irvine, Irvine CA

Investigators

Abstract

Forests and anthropogenic activities emit reactive gases that convert to fine particles by complex processes. Current models are unable to predict this secondary particle production and the particle properties limiting our ability to assess impacts on regional air quality and water cycle. This project will develop a detailed first principles model and calibrate it with measurements to predict secondary fine particle production, their properties and their impacts on ice and cloud formation in convective storms. The educational component will develop a web based interactive computational chemistry model to inform and attract students to atmospheric research. The research will harness a master chemical mechanism and a kinetic multi-layer model of gas-particle interactions in aerosols and clouds that explicitly resolves the phase sensitive reactions and mass transport at the particle surface and bulk. This new model will be constrained by laboratory data on size resolved particle phase and chemical composition of secondary organic aerosol (SOA) formation from organic gases. How this formation mechanism transitions and the SOA properties change as we go from isoprene (biogenic) to naphthalene (anthropogenic) organic gases will be investigated to gain molecular level insight. The simulations will be extended to convective regimes of relative humidity, temperatures and updraft velocities that involve ice-nucleation pathways for SOA particles and compared to recent laboratory measurements.