Dissolved black carbon (DBC) is the largest known slow-cycling organic carbon pool in the world’s oceans. Atmospheric deposition could significantly contribute to the oceanic DBC pool, but respective information is lacking. Here we estimate that, during the dust outbreak season, the atmospheric dry deposition of water-soluble black carbon (WSBC) is ~ 40% of the riverine input to the China coastal seas. The molecular composition of atmospheric WSBC determined by ultrahigh-resolution mass spectrometry, reveals similar soil-derived sources as for riverine discharge. WSBC is significantly positively correlated with water-soluble organic carbon (WSOC) in marine aerosols, and water-soluble black carbon contributes on average 2.8 ± 0.65% to the total WSOC. Based on this relationship, the global atmospheric deposition of DBC to the ocean is estimated to be 1.8 ± 0.83 Tg yr−1. Anticipated future changes in biomass burning and dust mobilization might increase these numbers, with consequences for regional ecosystems and global carbon reservoirs.
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机译:溶解黑碳(DBC)是世界上最大的已知慢循环有机碳库。大气沉积可能对海洋DBC池有重大贡献,但缺乏相应的信息。在这里,我们估计在粉尘暴发季节,水溶性黑碳(WSBC)在大气中的干沉降约为中国沿海海域河流输入量的40%。通过超高分辨率质谱法测定的大气WSBC的分子组成,揭示了与河流排放相似的土壤来源。 WSBC与海洋气溶胶中的水溶性有机碳(WSOC)呈显着正相关,而水溶性黑碳平均占总WSOC的2.8%±0.65%。基于这种关系,估计DBC在海洋中的全球大气沉积为1.8±0.83 Tg yr -1 sup>。预计未来生物质燃烧和动员粉尘的变化可能会增加这些数量,并对区域生态系统和全球碳库产生影响。
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