Coupling Measurements and Modeling to Understand the Lifecycle of Secondary Organic Aerosol over Local to Regional Scales
EMSL Project ID
50742
Abstract
Our hypothesis is that a better understanding of fast-reacting processes, such as the chemistry of volatile organic compounds associated with isoprene having a lifetime of ~minutes, is needed to make a breakthrough in parameterizing SOA for the next generation climate models. We propose to analyze unique EMSL data sets collected in the vicinity of the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site in Oklahoma during the summer of 2016 as part of the Holistic Interactions of Shallow Clouds, Aerosol, and Land-Ecosystems (HI-SCALE) field campaign. Extensive measurements of size, chemical composition, and mixing state of ambient non-refractory and refractory atmospheric aerosols have been obtained through on-line mass spectrometry, using EMSL's HR-ToF-AMS, miniSPLAT, and SPLAT II instruments. Data from these instruments will be coupled to high-resolution simulations. The following science question will guide the analyses of these measurements and address our hypothesis: What are the microphysical properties and mixing state of secondary organic aerosols (SOA) from biogenic and anthropogenic sources and how do those properties evolve temporally and spatially as a function of atmospheric processing within convective eddies?
Analyses of HI-SCALE data will enable new insights into the molecular-level understanding of gas-to-particle partitioning, aerosol mixing state, and aging over multiple time scales associated with coupling turbulent mixing within convective eddies (seconds to minutes), diurnal photochemistry and emission rates, and multi-day chemical processing associated with variable meteorology. It is computationally prohibitive for climate models to explicitly account for thousands of chemical reactions associated with SOA formation and transformation; therefore, new insights obtained from the field measurements will instead be used to better constrain parameterizations of SOA. EMSL's Cascade supercomputer provides a means to evaluate SOA predicted by Large-Eddy-Simulation (LES, delta-x ~ 10-100 m) and regional-scale (delta-x ~ 1-10 km) models that use both state-of-the-science and new parameterizations of SOA.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2019-10-01
End Date
2021-03-31
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Fast J.D. L.K. Berg Z. Feng F. Mei R.K. Newsom K. Sakaguchi and H. Xiao. 2019. The Impact of Variable Land-Atmosphere Coupling on Convective Cloud Populations Observed During the 2016 HI-SCALE Field Campaign. Journal of Advances in Modeling Earth Systems 11 no. 8:2629-2654. PNNL-SA-143151. doi:10.1029/2019MS001727