Arctic warming by abundant fine sea salt aerosols from blowing snow

• Published in: Nature geoscience Vol. 16; no. 9; pp. 768 - 774
• Main Authors: Gong, Xianda, Zhang, Jiaoshi, Croft, Betty, Yang, Xin, Frey, Markus M., Bergner, Nora, Chang, Rachel Y.-W., Creamean, Jessie M., Kuang, Chongai, Martin, Randall V., Ranjithkumar, Ananth, Sedlacek, Arthur J., Uin, Janek, Willmes, Sascha, Zawadowicz, Maria A., Pierce, Jeffrey R., Shupe, Matthew D., Schmale, Julia, Wang, Jian
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2023; Nature Publishing Group
• Subjects: 704/106/125; 704/106/35; 704/106/35/824; 704/172/4081; Aerosol production; Aerosols; Arctic climate changes; Arctic climates; Arctic clouds; Background levels; Blowing rate; Blowing snow; Blowing time; Chemical transport; Climate change; Cloud condensation nuclei; Cloud condensation nuclei concentrations; Cloud properties; Clouds; Condensates; Condensation; Condensation nuclei; Earth and Environmental Science; Earth Sciences; Earth System Sciences; Emissivity; Expeditions; Geochemistry; Geology; Geophysics/Geodesy; Global aerosols; Nucleus; Salts; Snow; Storms; Sublimation; Surface temperature; Arctic region
• ISSN: 1752-0894; 1752-0908
• DOI: 10.1038/s41561-023-01254-8

The Arctic warms nearly four times faster than the global average, and aerosols play an increasingly important role in Arctic climate change. In the Arctic, sea salt is a major aerosol component in terms of mass concentration during winter and spring. However, the mechanisms of sea salt aerosol production remain unclear. Sea salt aerosols are typically thought to be relatively large in size but low in number concentration, implying that their influence on cloud condensation nuclei population and cloud properties is generally minor. Here we present observational evidence of abundant sea salt aerosol production from blowing snow in the central Arctic. Blowing snow was observed more than 20% of the time from November to April. The sublimation of blowing snow generates high concentrations of fine-mode sea salt aerosol (diameter below 300 nm), enhancing cloud condensation nuclei concentrations up to tenfold above background levels. Using a global chemical transport model, we estimate that from November to April north of 70° N, sea salt aerosol produced from blowing snow accounts for about 27.6% of the total particle number, and the sea salt aerosol increases the longwave emissivity of clouds, leading to a calculated surface warming of +2.30 W m −2 under cloudy sky conditions. Fine sea salt aerosols produced by blowing snow in the Arctic impact cloud properties and warm the surface, according to observations from the MOSAiC expedition.