Solid organic-coated ammonium sulfate particles at high relative humidity in the summertime Arctic atmosphere

Authors

• Rachel M. Kirpes, University of Michigan, Ann Arbor
• Ziying Lei, University of Michigan, Ann Arbor
• Matthew Fraund, University of the PacificFollow
• Matthew J. Gunsch, University of Michigan, Ann Arbor
• Nathaniel W. May, University of Michigan, Ann Arbor
• Tate E. Barrett, Baylor University
• Claire E. Moffett, Baylor University
• Andrew J. Schauer, University of Washington
• Becky Alexander, University of Washington
• Lucia M. Upchurch, University of Washington
• Swarup China, Environmental Molecular Sciences Laboratory
• Patricia K. Quinn, NOAA Pacific Marine Environmental Laboratory
• Ryan C. Moffet, University of the PacificFollow
• Alexander Laskin, Environmental Molecular Sciences Laboratory
• Rebecca J. Sheesley, Baylor University
• Kerri A. Pratt, University of Michigan, Ann Arbor
• Andrew P. Ault, University of Michigan, Ann Arbor

Document Type

Article

Publication Title

Proceedings of the National Academy of Sciences of the United States of America

Department

Chemistry

ISSN

10916490

Volume

119

Issue

14

DOI

10.1073/pnas.2104496119

First Page

1

Last Page

6

Publication Date

4-5-2022

Abstract

The ability of atmospheric aerosols to impact climate through water uptake and cloud formation is fundamentally determined by the size, composition, and phase (liquid, semisolid, or solid) of individual particles. Particle phase is dependent on atmospheric conditions (relative humidity and temperature) and chemical composition and, importantly, solid particles can inhibit the uptake of water and other trace gases, even under humid conditions. Particles composed primarily of ammonium sulfate are presumed to be liquid at the relative humidities (67 to 98%) and temperatures (22 to 4°C) of the summertime Arctic. Under these atmospheric conditions, we report the observation of solid organic-coated ammonium sulfate particles representing 30% of particles, by number, in a key size range (<0.2 μm) for cloud activation within marine air masses from the Arctic Ocean at Utqiagvik, AK. The composition and size of the observed particles are consistent with recent Arctic modeling and observational results showing new particle formation and growth from dimethylsulfide oxidation to form sulfuric acid, reaction with ammonia, and condensation of marine biogenic sulfate and highly oxygenated organic molecules. Aqueous sulfate particles typically undergo efflorescence and solidify at relative humidities of less than 34%. Therefore, the observed solid phase is hypothesized to occur from contact efflorescence during collision of a newly formed Aitken mode sulfate particle with an organic-coated ammonium sulfate particle. With declining sea ice in the warming Arctic, this particle source is expected to increase with increasing open water and marine biogenic emissions.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Kirpes, Rachel M.; Lei, Ziying; Fraund, Matthew; Gunsch, Matthew J.; May, Nathaniel W.; Barrett, Tate E.; Moffett, Claire E.; Schauer, Andrew J.; Alexander, Becky; Upchurch, Lucia M.; China, Swarup; Quinn, Patricia K.; Moffet, Ryan C.; Laskin, Alexander; Sheesley, Rebecca J.; Pratt, Kerri A.; and Ault, Andrew P., "Solid organic-coated ammonium sulfate particles at high relative humidity in the summertime Arctic atmosphere" (2022). Pacific Faculty Work. 191.
https://scholarlycommons.pacific.edu/all-faculty/191