Oceanic production and occurrence of dimethyl sulfide (DMS) and its subsequent ventilation to the atmosphere significantly contribute to the global sulfur cycle and impact the climate regulation. Spatial distributions of DMS, dimethylsulfoniopropionate (DMSP, precursor of DMS), and dimethyl sulfoxide (DMSO, oxidation product of DMS), production and removal processes of DMS (including biological production, microbial consumption, photo-degradation, and sea-to-air exchange), and biogenic contributions to the atmospheric sulfate burden were simultaneously studied in the western Pacific Ocean during winter. Sea surface DMS, DMSP, and DMSO were strongly correlated and had similar distribution patterns. The DMS photo-degradation efficiency ratio (normalized using incident photon flux density) for ultraviolet B radiation (UVB): ultraviolet A radiation (UVA): photosynthetically active radiation (PAR) was 391: 36: 1. However, considering the solar spectral composition, the actual contributions of UVB, UVA, and PAR to DMS photo-degradation in surface waters were 40.6% ± 10.7%, 41.2% ± 15.6%, and 18.2% ± 7.2%, respectively. When integrated across the entire mixed layer, UVA and PAR became the dominant drivers, accounting for 45.2% ± 18.0% and 38.0% ± 17.3% of DMS photo-degradation, respectively, as UVB was significantly attenuated in seawater. The DMS budget of the entire mixed layer indicated that microbial consumption, photo-degradation, and ventilation accounted for about 74.3% ± 11.9%, 19.3% ± 9.3%, and 6.5% ± 4.0% of total DMS removal, respectively. Even if ventilation was a minor DMS removal pathway, DMS emissions still contributed approximately 45.2% ± 25.6% of the atmospheric non-sea-salt sulfate burden over the western Pacific Ocean.

中文翻译：

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西太平洋二甲基硫醚的发生与循环

海洋中二甲基硫醚 (DMS) 的产生和发生及其随后向大气的通风显着促进了全球硫循环并影响了气候调节。DMS、二甲基磺基丙酸酯（DMSP，DMS的前体）和二甲亚砜（DMSO，DMS的氧化产物）的空间分布，DMS的生产和去除过程（包括生物生产、微生物消耗、光降解和海空交换），同时研究了冬季西太平洋对大气硫酸盐负荷的生物成因贡献。海面 DMS、DMSP 和 DMSO 具有很强的相关性并且具有相似的分布模式。紫外线 B 辐射 (UVB) 的 DMS 光降解效率比（使用入射光子通量密度归一化）：紫外线A辐射（UVA）：光合有效辐射（PAR）为391：36：1。 然而，考虑到太阳光谱组成，UVB、UVA和PAR对地表水中DMS光降解的实际贡献为40.6%±分别为 10.7%、41.2% ± 15.6% 和 18.2% ± 7.2%。当整合到整个混合层时，UVA 和 PAR 成为主要驱动因素，分别占 DMS 光降解的 45.2% ± 18.0% 和 38.0% ± 17.3%，因为 UVB 在海水中显着衰减。整个混合层的 DMS 预算表明，微生物消耗、光降解和通风分别约占 DMS 去除总量的 74.3% ± 11.9%、19.3% ± 9.3% 和 6.5% ± 4.0%。即使通风是次要的 DMS 去除途径，DMS 排放仍然贡献了大约 45.2% ± 25。