The Role of Atmospheric Particle Acidity in Health and Climate Effects

Abstract

Atmospheric aerosols play a crucial role in air quality, climate, and human health, yet their chemical complexity remains a challenge for global modeling and mitigation strategies. Aerosol acidity (pH) is a key factor that governs key atmospheric chemistry, including secondary organic aerosol (SOA) formation, cloud microphysics, and ice nucleation ability, with significant implications for climate and atmospheric processes. However, accurately measuring the acidity of individual particles has remained a challenge due to the small size of aerosols. Our study aims to develop a novel method to directly measure the acidity of individual atmospheric particles. Using state-of-the-art spectroscopic and microscopic techniques, this approach reveals how acidity affects SOA formation via acid-catalyzed reactions and how these transformations alter aerosol morphology, phase state, and chemical composition. Additionally, our findings demonstrate that particle acidity can also affect their ice nucleation activity, shedding light on its potential role in cloud microphysics and precipitation formation. The goal of our research is to bridge atmospheric chemistry, environmental engineering, and climate science to highlight the importance of addressing aerosol acidity in climate models and air quality assessments.

Biography

Ziying (Nancy) Lei, Assistant Professor in the Department of Chemistry at the University of Tennessee, Knoxville (UT), specializes in atmospheric aerosol chemistry and cloud microphysics. Her research focuses on the physicochemical properties of atmospheric aerosols and their cloud condensation and ice nucleation potential using cutting edge microscopy and spectroscopy techniques. Lei's research combines field measurements and laboratory experiments to improve understanding of aerosol-cloud interactions, air quality, and climate impacts. Her work has contributed to large-scale Department of Energy (DOE) field campaigns, including TRACER, which examined aerosol impacts on deep convection. Her current research is focusing on studying biogenic aerosols, biomass burning emissions, and cloud formation.

Before joining UT, Lei was a Geoscience Future Faculty Postdoc Fellow at Texas A&M University in the Department of Atmospheric Science. She earned her PhD in the School of Public Health, environmental health science and Chemistry Department from the University of Michigan-Ann Arbor. Prior to that, she completed her MS in civil and environmental engineering at The Ohio State University and her BS in earth science at Guilin University of Technology. Lei has received the DOE ASR research grant during her postdoc, and her work has been widely recognized in leading environmental and atmospheric science journals. With over 1,000 citations on Google Scholar, her research has made significant contributions to the field of atmospheric aerosol chemistry, improving understanding of aerosol-climate interactions and air pollution.