Characterizing Wintertime Aerosol Composition and Sulfate Formation, Fairbanks, Alaska

Fairbanks, Alaska is classified as a “serious non-attainment zone” due to the exposure of high levels of air pollutants throughout the winter months. This causes the city to violate the Fine Particulate Matter (PM2.5) National Ambient Air Quality Standards (NAAQS) set in place by the United States Environmental Protection Agency (EPA).1,2 On average, Fairbanks has a PM2.5 level between 40 to 70 micrograms per cubic meter (μg m-3) and up to 200 μg m-3 in the winter months, exceeding the NAAQS limit of 35 μg m-3.3 In addition, the American Lung Association recently classified Fairbanks as the most polluted city for annual PM2.5 pollution in the United States.4 These fine particulates, with a diameter less than 2.5 μm, are pollutants that cause major health risks to the citizens of Fairbanks. Previous studies have shown the significant amount of sulfate aerosols observed in Fairbanks winters, but the chemical transformation of these aerosols in the atmosphere are still unknown.1 The oxidants that commonly catalyze secondary aerosol formation are limited in winter months, indicating formation occurs through a non-traditional pathway. This project will investigate the mechanism in which transition metals catalyze formation. By establishing a link between the two species and a mechanism of formation, the high PM2.5 levels will be investigated. Data collected from this previous year is shown in Appendix A and indicated another sample year will greatly aid in drawing crucial conclusions. By characterizing ambient aerosols using observation data, Fairbanks air quality may be improved to limit the impact on human health. Additionally, this project will provide knowledge about the unknown winter aerosol formation, which may be applied to arctic and polluted cities around the world. This coincides with NASA’s first Strategic Goal to broaden human knowledge through new scientific discoveries in addition to improving the quality of life on our planet.