The Diverse Physicochemical Mixing State of Aerosol Particles during TRacking Aerosol Convection inteRactions Experiment (TRACER) Campaign
ZIYING LEI, Seth Thompson, Bo Chen, Taylor Peña, Brianna Matthews, Ron Li, Anita Rapp, Christopher Nowotarski, Sarah D. Brooks, University of Tennessee
Abstract Number: 636
Working Group: Aerosols, Clouds and Climate
Abstract
To improve our understanding of how aerosols influence cloud properties in convective storms, we aim to provide detailed physicochemical characterization of individual submicron aerosols collected during the DOE’s TRacking Aerosol Convection inteRactions Experiment (TRACER) in the Greater Houston Area. In this study, computer-controlled Raman microspectroscopy was used to provide detailed morphology and chemical composition of thousands of individual particles. Our results reveal a great diversity of aerosols during the TRACER campaign, with significant differences in morphology (i.e., core-shell, homogeneous, and complex mixing) and chemical composition between coastal and inland locations. During hot summer days, development of the sea breeze often led to the initiation of convective storms in the urban area. Inland propagation of the sea breeze resulted in air masses that originated in the Gulf of Mexico passing over the Galveston sampling site, over central Houston, and to our inland sampling location. During sea breeze convective days, particles near the Gulf of Mexico exhibited a higher percentage of organic compounds, ranging from 69.6% to 97.8%, while those at the inland site contained a higher percentage of inorganic compounds, ranging from 5.0% to 41.4%. Additionally, variations in aerosol morphology and chemical composition were linked to differences in cloud condensation nucleation concentrations observed between the coastal and inland locations. The observed variations in aerosol characteristics illustrate the challenge of attributing any observed changes in convective cloud systems to aerosols, as the aerosol inputs vary from airmass to airmass. Our study enhances understanding of aerosol physicochemical properties and their role in microphysics and aerosol-cloud interactions during TRACER.