Ice core methanesulfonic acid from the Begguya (Mount Hunter) plateau, Denali National Park, Alaska, 2013 ...

• Main Authors: Chalif, Jacob, Osterberg, Erich, Winski, Dominic, Kreutz, Karl, Wake, Cameron, Koffman, Bess, Ferris, David
• Format: Dataset
• Language: English
• Published: NSF Arctic Data Center 2024
• Subjects: Ice core; Paleoclimate; Phytoplankton; Methanesulfonic acid; MSA; Biogenic sulfur; Primary production; Pollution; Industrialization; Denali; Alaska; Greenland; Greenland ice core; ice core; North Atlantic
• Online Access: https://dx.doi.org/10.18739/a2q814t9k; https://arcticdata.io/catalog/view/doi:10.18739/A2Q814T9K

An industrial-era drop in Greenland ice core methanesulfonic acid is thought to herald a collapse in North Atlantic marine phytoplankton stocks related to a weakening of the Atlantic meridional overturning circulation. In contrast, stable levels of marine biogenic sulfur production contradict this interpretation, and point to changes in atmospheric oxidation as a potential cause of the methanesulfonic acid decline. However, the impact of oxidation on methanesulfonic acid production has not been quantified, nor has this hypothesis been rigorously tested. Here we present a multi-century methanesulfonic acid record from the Denali, Alaska, ice core, which shows a methanesulfonic acid decline similar in magnitude but delayed by 93 years relative to the Greenland record. Box model results using updated dimethyl sulfide oxidation pathways indicate that oxidation by pollution-driven nitrate radicals has suppressed atmospheric methanesulfonic acid production, explaining most, if not all, of Denali’s and Greenland’s ...