Work

Methanethiol Abundance and Oxidation in a Polluted Marine Atmosphere

Year: 2025

Type: article

Abstract: Biological activity in the surface ocean leads to emissions of methanethiol (MeSH) and dimethyl sulfide (DMS). Measurements of MeSH in the marine atmosphere are sparse and the impact of NO x pollution on MeSH oxidation remains unexplored. We present measurements of MeSH and DMS at a coastal site with NO x up to 24.3 ppb in the United Kingdom during May and June. Winds coming from the seaward (northerly) direction showed a median (25th quantiles) MeSH mixing ratio of 15.7 (7.9–26.9) ppt. The measurements reveal significantly lower MeSH during daytime. Atmospheric box model calculations suggest that ∼25% of the MeSH oxidation is initiated by NO 3 at this site and that NO x pollution can reduce the SO 2 yield from MeSH. This work is further evidence for the prevalence of MeSH and illustrates the impact of NO x pollution on MeSH oxidation with associated implications for its role in aerosol‐cloud processes, and climate.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl114929

Authors: Charel Wohl, Grant L. Forster, Pete M. Edwards, Parvadha Suntharalingam, David E. Oram

Institutions: University of East Anglia, University of York

Language: English

Topic: Atmospheric chemistry and aerosols

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDG: Climate action

Open Access status: gold

Estimated APC paid: $3,190