Biogenic emissions of dimethylsulfide (DMS) are an important source of sulfur to the atmosphere, with implications for aerosol formation and cloud albedo over the ocean. Natural aerosol sources constitute the largest uncertainty in estimates of aerosol radiative forcing and climate and thus, an improved understanding of DMS sources is needed. Coral reefs are strong point sources of DMS; however, this coral source of biogenic sulfur is not explicitly included in climatologies or in model simulations. Consequently, the role of coral reefs in local and regional climate remains uncertain. We aim to improve the representation of tropical coral reefs in DMS databases by calculating a climatology of seawater DMS concentration (DMS_w) and sea‐air flux in the Great Barrier Reef (GBR), Australia. DMS_w is calculated from remotely sensed observations of sea surface temperature and photosynthetically active radiation using a multiple linear regression model derived from field observations of DMS_w in the GBR. We estimate that coral reefs and lagoon waters in the GBR (∼347,000 km²) release 0.03–0.05 Tg yr⁻¹ of DMS (0.02 Tg yr⁻¹ of sulfur). Based on this estimate, global tropical coral reefs (∼600,000 km²) could emit 0.08 Tg yr⁻¹ of DMS (0.04 Tg yr⁻¹ of sulfur), with the potential to influence the local radiative balance.

中文翻译：

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参数化大堡礁中海水温度和辐照度对二甲基硫（DMS）的影响以及珊瑚礁对全球硫循环的贡献

二甲基硫醚（DMS）的生物排放是大气中硫的重要来源，对海洋上的气溶胶形成和云量反照率有影响。天然气溶胶来源是气溶胶辐射强迫和气候估计中最大的不确定因素，因此，需要对DMS来源有更好的了解。珊瑚礁是DMS的重要来源；但是，这种生物源硫的珊瑚来源并未明确包含在气候或模型模拟中。因此，珊瑚礁在当地和区域气候中的作用仍然不确定。我们旨在通过计算澳大利亚大堡礁（GBR）的海水DMS浓度（DMS _w）和海气通量的气候学，来改善DMS数据库中热带珊瑚礁的表示。DMS _w使用从GBR中DMS _w的野外观测获得的多元线性回归模型，通过对海面温度和光合有效辐射的遥感观测计算得出。我们估计GBR（〜347,000 km ²）中的珊瑚礁和泻湖水释放出DMS的0.03-0.05 Tg yr ^-1（硫0.02 Tg yr ^-1）。根据这一估计，全球热带珊瑚礁（约600,000 km ²）可以排放0.08 Tg yr ^-1的DMS（0.04 Tg yr ^-1的硫），并有可能影响当地的辐射平衡。