Elucidating New Particle Formation in Complex Terrain during the Winter 2022 CFACT Campaign
Anna Gannet Hallar, Eric R. Pardyjak, Sebastian W. Hoch, Zhaoxia Pu, GERARDO CARRILLO-CARDENAS,
University of Utah Abstract Number: 609
Working Group: Aerosols, Clouds and Climate
AbstractNew particle formation (NPF) is a complex atmospheric phenomenon characterized by the sudden burst and growth in aerosol particles. Depending on its intensity and growth, NPF can contribute to aerosol loading in urban and remote regions, degrading air quality and inhibiting public health. Previous studies have shown that NPF contributes to the formation of cloud condensation nuclei (CCN), changing the overall composition of clouds and modifying their effects on climate. Over the past 20 years, numerous field studies have improved our understanding of NPF and highlighted possible chemical and physical processes required to initiate NPF. For instance, Boundary-Layer mechanisms such as turbulent mixing lead to the decoupling of different atmospheric reservoirs that help initiate NPF. However, it is not easy to quantify how a specific process influences NPF due to complex physical interactions between the atmosphere, land surfaces, and intricate chemical precursors needed for aerosol formation. The research presented here will help better understand which atmospheric processes enhance or limit NPF. This research uses observations from an extensive field study, CFACT (Cold Fog Amongst Complex Terrain), conducted in the Heber Valley of northern Utah during the winter of 2022. In situ measurements and derived variables will be incorporated into a positive matrix factorization model (PMF) to quantify the role of specific boundary-layer processes and meteorological variables on NPF. We use a radiative transfer model to compare observed and modeled UV radiation outputs and investigate the effect of radiative energy exchange on photochemistry for NPF. Results from this research will elucidate the interface between Boundary-Layer processes and NPF. Doing so will help inform air quality policy in mountainous terrain and address climate concerns.