Abstract View
Plume Heights Affect the Evolution of Organic Aerosol Optical Properties: Insights from FIREX-AQ Field Measurements
CHENCHONG ZHANG, Benjamin Sumlin, Nishit Shetty, Pai Liu, Rajan K. Chakrabarty, Washington University in St. Louis
Abstract Number: 354
Working Group: Wildfire Aerosols
Abstract
Light-absorbing organic carbon (LAOC) is one of the major components of smoke plumes from biomass burning (BB) events. The atmospheric processing of emitted LAOC in atmospheric transport could have a significant influence on regional radiative forcing and air quality. The spatiotemporal evolution of LAOC optical properties from BB events and their radiative implications are poorly understood, which limits this process-based parameterization in radiative transfer (RT) and chemical transport models (CTMs). Here we synergistically integrate the insights gained from satellite measurements, CTM, and field measurements to investigate the impacts of atmospheric processing on LAOC emitted during the field study portion of the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign. We incorporate an experimentally constrained radical volatility basis set (VBS) into the WRF-Chem (Weather Research and Forecasting model coupled with Chemistry) CTM to account for the chemical composition of the spatially evolving plume particles. The optical properties of LAOC as a function of photochemical aging are correlated with their fractional compositions in this model. Our simulation results from the CTM are further compared with satellite observations and ground-based measurements to validate the reliable representation of the atmospheric processing for LAOC. Our constrained modeling results show that atmospheric processing of LAOC significantly depends on the smoke plume heights, resulting in stratified vertical profiles of absorption optical depths as a function of photochemical aging. We anticipate our findings to provide better insights for improving LAOC representation in current RTs and CTMs.