Identification of Individual Residential Wood Burning Aerosols and Secondary Aerosol Formation during Wintertime Fairbanks, Alaska

ANDREW HOLEN, Judy Wu, Ellis Robinson, Karolina Cysneiros de Carvalho, Damien Ketcherside, Vanessa Selimovic, William Simpson, Lu Hu, Brent Williams, Peter F. DeCarlo, Kerri Pratt, University of Michigan

     Abstract Number: 368
     Working Group: Biomass Combustion: Outdoor/Indoor Transport and Indoor Air Quality

Abstract
Severe wintertime air pollution, particularly in high latitude cities, is understudied and gaining significant attention due to adverse human health effects. Specifically, Fairbanks, Alaska experiences some of the highest PM_2.5 (particulate matter < 2.5 µm) levels in the United States largely due to a combination of increased heating needs and strong wintertime atmospheric inversions that trap pollutants near the ground. Previous measurements show that organic carbon and sulfate dominate PM_2.5 during pollution events, but uncertainties surround the contributing sources, including a variety of residential heating methods. Therefore, the Alaskan Layered Pollution and Chemical Analysis (ALPACA) field campaign was conducted in Fairbanks, AK, from Jan. 17 – Feb. 26, 2022. Here, we focus on measurements made using an aerosol time-of-flight mass spectrometer (ATOFMS), which provided individual aerosol particle size, chemical composition, and mixing state in real-time. Individual particle mass spectra provide a “chemical fingerprint” of the primary particle source and any secondary aerosol formation. Simultaneous aerosol size distribution measurements were also conducted. Together these methods provide quantitative identification of individual aerosol sources. In particular, we evaluate domestic heating (oil, wood, coal) and local power generation (coal and oil) as sources of combustion aerosol. In addition, we examine the internal mixing state of secondary aerosol species with biomass burning aerosols. These results improve the understanding of wintertime aerosol chemical composition, sources, and processes.