研究人员表示，海洋排放的二甲基硫化物（DMS）是气候冷却气溶胶的主要来源。然而，大多数海洋生物硫循环不是流向DMS，而是流向甲烷硫醇（MeSH），这是另一种挥发性物质，其反应性迄今为止阻碍了测量。因此，MeSH的全球排放和气候影响仍未被探索。
研究人员编制了一个海水MeSH浓度数据库，确定了它们的统计预测因子，并生成了全球海洋MeSH排放量加上DMS排放量的月度数据。在全球化学-气候模式中，MeSH排放使南大洋上空的硫酸盐气溶胶负担增加了30%至70%，并增强了气溶胶冷却效果，同时耗尽了大气氧化剂，增加了DMS的寿命和运输。计算MeSH排放减少了当前气候模式在该气候相关区域的辐射偏差。
附：英文原文
Title: Marine emissions of methanethiol increase aerosol cooling in the Southern Ocean
Author: Charel Wohl, Julián Villamayor, Martí Galí, Anoop S. Mahajan, Rafael P. Fernández, Carlos A. Cuevas, Adriana Bossolasco, Qinyi Li, Anthony J. Kettle, Tara Williams, Roland Sarda-Esteve, Valérie Gros, Rafel Simó, Alfonso Saiz-Lopez
Issue&Volume: 2024-11-29
Abstract: Ocean-emitted dimethyl sulfide (DMS) is a major source of climate-cooling aerosols. However, most of the marine biogenic sulfur cycling is not routed to DMS but to methanethiol (MeSH), another volatile whose reactivity has hitherto hampered measurements. Therefore, the global emissions and climate impact of MeSH remain unexplored. We compiled a database of seawater MeSH concentrations, identified their statistical predictors, and produced monthly fields of global marine MeSH emissions adding to DMS emissions. Implemented into a global chemistry-climate model, MeSH emissions increase the sulfate aerosol burden by 30 to 70% over the Southern Ocean and enhance the aerosol cooling effect while depleting atmospheric oxidants and increasing DMS lifetime and transport. Accounting for MeSH emissions reduces the radiative bias of current climate models in this climatically relevant region.
DOI: adq2465
Source: https://www.science.org/doi/10.1126/sciadv.adq2465