Abstract View
Inorganic PM2.5 Composition in Fairbanks Alaska Winter: Large Contributions from HMS
MICHAEL BATTAGLIA JR., Rime El Asmar, James Campbell, Meeta Cesler-Maloney, William Simpson, Jingqiu Mao, Athanasios Nenes, Rodney J. Weber, Georgia Institute of Technology
Abstract Number: 382
Working Group: Aerosol Chemistry
Abstract
Fairbanks, Alaska, is a near-Arctic, in-land city known to experience intense winter-time atmospheric inversions with high concentrations of PM2.5 mass that often exceed air quality standards. In preparation for the Sustainably Navigating Arctic Pollution -- Through Engaging Communities (SNAP-TEC) field study planned for 2022, we characterized ambient wintertime aerosols in Fairbanks during January-March 2020. An Aerodyne ASCM configured for PM2.5 sampling was deployed to begin the first year-long continuous speciated PM2.5 mass-spectrometer measurement in Alaska. A particle-into-liquid sampler coupled to ion chromatograph (PILS-IC) utilizing Metrohm columns and eluents was used to characterize water-soluble anions from Jan-March, with a specific interest in separately measuring hydroxymethanesulfonate (HMS) and inorganic sulfate. Daily filter samples were analyzed by anion and cation ICs for comparisons with online instruments. Additionally, MOUDIs continuously sampled for 3-5 days were deployed and used to develop size distributions of anions and cations. ACSM analysis revealed that fine aerosols in Fairbanks were dominated by organic species, typically comprising about 60% of the PM2.5 mass. During periods of intense inversions and extreme cold, HMS was found at concentrations similar to those of inorganic sulfate, both at times reaching concentrations over 10 ug per cubic meter. The source of the HMS is being investigated, factors include high emissions, higher gas-to-particle conversion, and possibly other formation mechanisms that are enhanced at lower temperatures. Delineating the HMS and inorganic sulfate may provide improved methods for reducing the high levels of PM2.5 found in Fairbanks during winter months.