Global airborne sampling reveals a previously unobserved dimethyl sulfide oxidation mechanism in the marine atmosphere

• DOI: 10.1073/pnas.1919344117
• Publication Date: 2020-02-18T23:14:27Z
• Authors: Patrick R. Veres; J. Andrew Neuman; Timothy H. Bertram; Emmanuel Assaf; Glenn M. Wolfe; Christina J. Will...; Bernadett Weinzierl; Simone Tilmes; Chelsea R. Thompson; Alexander B. Thames; Jason C. Schroder; Alfonso Saiz-Lopez; Andrew W. Rollins; James M. Roberts; Derek Price; Jeff Peischl; Benjamin A. Nault; Kristian H. Møller; David O. Miller; Simone Meinardi; Qinyi Li; Jean-François Lam...; Agnieszka Kupc; Henrik G. Kjaergaard; Douglas Kinnison; Jose L. Jimenez; Christopher M. Je...; Rebecca S. Hornbrook; Alan Hills; Maximilian Dollner; Douglas A. Day; Carlos A. Cuevas; Pedro Campuzano-Jost; James Burkholder; T. Paul Bui; William H. Brune; Steven S. Brown; Charles A. Brock; Ilann Bourgeois; Donald R. Blake; Eric C. Apel; Thomas B. Ryerson
• Keywords: 103008 Experimental physics; SDG 14 – Leben unter Wasser; 103008 Experimentalphysik; 103039 Aerosol physics; 01 natural sciences; Atmospheric Sciences; Climate Action; marine aerosols; autoxidation; 13. Climate action; 103037 Environmental physics; SDG 13 – Maßnahmen zum Klimaschutz; Earth Sciences; SDG 13 - Climate Action; SDG 14 - Life Below Water; 14. Life underwater; marine sulfur; 103039 Aerosolphysik; dimethyl sulfide; aerosol sulfate; 103037 Umweltphysik; 0105 earth and related environmental sciences

Dimethyl sulfide (DMS), emitted from the oceans, is the most abundant biological source of sulfur to the marine atmosphere. Atmospheric DMS is oxidized to condensable products that form secondary aerosols that affect Earth’s radiative balance by scattering solar radiation and serving as cloud condensation nuclei. We report the atmospheric discovery of a previously unquantified DMS oxidation product, hydroperoxymethyl thioformate (HPMTF, HOOCH2SCHO), identified through global-scale airborne observations that demonstrate it to be a major reservoir of marine sulfur. Observationally constrained model results show that more than 30% of oceanic DMS emitted to the atmosphere forms HPMTF. Coincident particle measurements suggest a strong link between HPMTF concentration and new particle formation and growth. Analyses of these observations show that HPMTF chemistry must be included in atmospheric models to improve representation of key linkages between the biogeochemistry of the ocean, marine aerosol formation and growth, and their combined effects on climate.