Hydroxymethanesulfonate (HMS) Formation during Summertime Fog in an Arctic Oil Field

• Published in: Environmental Science & Technology Letters
• Main Authors: Liu, Jun, Gunsch, Matthew J., Moffett, Claire E., Xu, Lu, El Asmar, Rime, Zhang, Qi, Watson, Thomas B., Allen, Hannah M., Crounse, John D., St. Clair, Jason, Kim, Michelle, Wennberg, Paul O., Weber, Rodney J., Sheesley, Rebecca J., Pratt, Kerri A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Chemical Society 2021
• Subjects: Lipids; Anions; Liquids; Aerosols; Particulate matter; Beaufort Sea
• Online Access: https://doi.org/10.1021/acs.estlett.1c00357

Hydroxymethanesulfonate (HMS) is produced in the aqueous-phase reaction of formaldehyde (HCHO) and sulfur dioxide (SO₂) and has been proposed as a significant contributor to midlatitude wintertime pollution events. Here we report HMS detection within submicrometer atmospheric aerosols during frequent late summer, regional fog events in an Arctic oil field. The number fraction of individual particles containing HMS increased during fog periods, consistent with aqueous-phase formation. The single-particle mass spectra showed the primary particle signature (oil field emissions), plus secondary oxidized organics and sulfate, consistent with aqueous-phase processing. HMS mass concentrations ranged from below the ion chromatography limit of detection (0.3 ng/m³) to 1.6 ng/m³, with sulfate concentrations of 37–222 ng/m³. HCHO and SO₂ measurements suggest that the fog HMS production rate is ∼10 times higher in the oil fields than in the upwind Beaufort Sea. Aqueous-phase reactions of local oil field emissions during frequent summertime regional fog events likely have downwind impacts on Arctic aerosol composition. The potential for fog-based HMS production was estimated to be an order of magnitude higher in Fairbanks and Anchorage, AK, than in the oil fields and may explain the missing organosulfate source contributing to Fairbanks air quality. © 2021 American Chemical Society. Received: May 9, 2021; Revised: June 16, 2021; Accepted: June 18, 2021. This study was supported by the NOAA Climate Program Office and Atmospheric Chemistry, Carbon Cycle, and Climate Program through NA14OAR4310149 (University of Michigan) and NA14OAR4310150 (Baylor University) and a Department of Energy (DOE) Early Career Award (DE-SC0019172). The field work was also supported in part by the DOE Office of Biological and Environmental Research (BER) ARM Climate Research Facility (field campaign 2013-6660). This research was also supported by a National Academies of Sciences, Engineering, and Medicine Gulf Research Program ...