Hydroxymethanesulfonate and Sulfur(IV) in Fairbanks Winter During the ALPACA Study
Abstract
Hydroxymethanesulfonate (HMS) in fine aerosol particles has been reported at significant concentrations along with sulfate under extreme cold conditions (-35 °C) in Fairbanks, Alaska, a high latitude city. HMS, a component of S(IV) and an adduct of formaldehyde and sulfur dioxide, forms in liquid water. Previous studies may have overestimated HMS concentrations by grouping it with other S(IV) species. In this work, we further investigate HMS and the speciation of S(IV) through the Alaskan Layered Pollution and Chemical Analysis (ALPACA) intensive study in Fairbanks. We developed a method utilizing hydrogen peroxide to isolate HMS and found that approximately 50% of S(IV) is HMS for total suspended particulates and 70% for PM2.5. The remaining unidentified S(IV) species are closely linked to HMS during cold polluted periods, showing strong increases in concentration relative to sulfate with decreasing temperature, a weak dependence on particle water, and similar particle size distributions, suggesting a common aqueous formation process. A portion of the unidentified S(IV) may originate from additional aldehyde-S(IV) adducts that are unstable in the water-based chemical analysis process, but further chemical characterization is needed. These results show the importance of organic S(IV) species in extreme cold environments that promote unique aqueous chemistry in supercooled liquid particles.
Copyright and License
© 2024 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0.
Acknowledgement
We thank the entire ALPACA science team of researchers for designing the experiment, acquiring funding, making measurements, and ongoing analysis of the results. The ALPACA project was initiated as a part of PACES under IGAC and with the support of IASC. We thank the University of Alaska Fairbanks and the Geophysical Institute for logistical support, and Fairbanks for welcoming and engaging with this research. We thank the Alaska Department of Environmental Conservation (ADEC) for data collection at the NCORE site. K.D., E. H., M.B., and R.J.W. were supported by the National Science Foundation’s (NSF) Atmospheric Geoscience Program (grant no. AGS-2029730) and the NSF Navigating the New Arctic Program (grant no. NNA-1927778). M.B. was also supported by NASA (grant no. 80NSSC18K0557). M. C-M. and W.R.S. were supported by the NSF Sustainably Navigating Arctic Pollution Through Engaging Communities (SNAP-TEC) Program (grant no. 1927750). J.S.C. was supported by the NSF Atmospheric Geoscience Program (grant no. AGS-2029770). J.E.D. was supported by the National Science Foundation’s (NSF) Atmospheric Geoscience Program (grant no. AGS-2109023). B. T-R. and B.A. were funded by the CASPA (Climate-relevant Aerosol Sources and Processes in the Arctic) project of the Agence Nationale de la Recherche (grant ANR-21-CE01-0017) and the IPEV (French Polar Institute Paul-Émile Victor). A.M and B. A. were supported by grant NA20OAR4310295NA20OAR4310295 from NOAA. A.N. was supported by the European Research Council (ERC) project “PyroTRACH” (Grant agreement No. 726165). J.R.C. and J.M. were supported by the NSF Atmospheric Geoscience Program (grant no. AGS-2029747) and the NSF Navigating the New Arctic Program (grant no. NNA-1927750).
Data Availability
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Discussion of relative role of HCHO and SO2 in HMS formation during severe cold pollution events; MOUDI cut sizes and particle diameter size range; summary of MOUDI sample collection periods and flow conditions; retention times for anion IC analysis using GT and UNH systems; quantification of HMS standard stability and resistance to oxidation by H2O2; quantification of bisulfite standard stability and removal by H2O2; decay of bisulfite peak area over time; decay of sulfite peak area over time; quantification of sulfite removal by H2O2; averages and statistical error of precursors, S(IV), HMS, sulfate, PM2.5, and temperature during 2020, 2021, and 2022 study periods; possible artifacts in PTR-ToF-MS measurements of aldehydes; diagram of filter storage and analysis process; investigation of bias at low concentrations of S(IV); S(IV) time series during 2020, 2021, and 2022 study period highlights; plots of HMS and normalized HMS vs. S(IV) and normalized S(IV); size distributions of sulfate and S(IV) in MOUDI samples; size distributions of HMS and other S(IV) in MOUDI samples; select size distributions with statistical analysis for mild, moderate, and severe pollution periods; ALWC vs. RH during the 2022 campaign; select aldehyde concentrations vs. formaldehyde; gas phase HCHO vs. SO2 during the 2022, colored by date; time series and S(IV)/sulfate vs. RH of major pollution events from 2020 and 2022 campaigns; S(IV)/sulfate vs. HCHO/SO2 during major pollution events from 2020 and 2022 campaigns; time series and ratio of gas phase HCHO and SO2 concentrations. (PDF)
Conflict of Interest
The authors declare no competing financial interest.
Files
dingilian-et-al-2024-hydroxymethanesulfonate-and-sulfur(iv)-in-fairbanks-winter-during-the-alpaca-study.pdf
Additional details
Identifiers
- ISSN
- 2837-1402
Funding
- National Science Foundation
- AGS-2029730
- National Science Foundation
- RISE-1927778
- National Aeronautics and Space Administration
- 80NSSC18K0557
- National Science Foundation
- RISE-1927750
- National Science Foundation
- AGS-2029770
- National Science Foundation
- AGS-2109023
- Agence Nationale de la Recherche
- ANR-21-CE01-0017
- Institut Polaire Français Paul Émile Victor
- National Oceanic and Atmospheric Administration
- NA20OAR4310295NA20OAR4310295
- European Research Council
- 726165
- National Science Foundation
- AGS-2029747