Trapped in the Inversion Layer: Composition and Morphology of Single Aerosol Particles in the Urban Arctic Winter

EMILY COSTA, Jessica Mirrielees, Jessie Creamean, Andrew Holen, Judy Wu, Swarup China, Kerri Pratt, University of Michigan

     Abstract Number: 568
     Working Group: Aerosol Chemistry

Abstract
Air pollution in Arctic cities is a critical yet often overlooked problem. Atmospheric inversion layers can lead to the accumulation of pollutants over time, resulting in levels of airborne particulate matter that often exceed air quality standards. These temperature inversions can also result in the formation of ice fog, a hazardous form of air pollution that occurs at low temperatures as small ice crystals with low gravitational settling rates remain airborne for extended periods of time. Aerosols known as ice nucleating particles (INPs) can contribute to ice fog formation; however, many questions remain due to the limited observations of these processes. The composition and chemical transformations of aerosols in this region are not well characterized. To better understand wintertime urban air quality, aerosol particle samples were collected during January-February 2022 during the Alaskan Layered Pollution and Chemical Analysis (ALPACA) field campaign in Fairbanks, AK. Individual particles are analyzed using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) to study their morphology and elemental composition. The types of aerosols present in the polluted city of Fairbanks and during ice fog events are characterized using these size-resolved chemical composition data. This method provides identification of the main components and sources of wintertime aerosol particles in Fairbanks impacting ice fog formation and air quality.