Bao Hongyan, Niggemann Jutta, Luo Li, Dittmar Thorsten, Kao Shuh-Ji
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China.
Collage of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
Nat Commun. 2017 Sep 11;8(1):510. doi: 10.1038/s41467-017-00437-3.
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. Anticipated future changes in biomass burning and dust mobilization might increase these numbers, with consequences for regional ecosystems and global carbon reservoirs.The contribution of atmospheric deposition to the oceanic dissolved black carbon pool (DBC) is unclear. Here, the authors show that water-soluble black carbon is positively correlated with water-soluble organic carbon in marine aerosols, and that atmospheric deposition is a significant source of oceanic DBC.
溶解态黑碳（DBC）是全球海洋中已知最大的缓慢循环有机碳库。大气沉降可能对海洋DBC库有显著贡献，但相关信息尚缺。在此我们估计，在沙尘暴发季节，水溶性黑碳（WSBC）的大气干沉降量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，揭示出与河流排放类似的土壤来源。WSBC与海洋气溶胶中的水溶性有机碳（WSOC）显著正相关，且水溶性黑碳平均占总WSOC的2.8±0.65%。基于这种关系，估计全球大气向海洋的DBC沉降量为1.8±0.83太克/年。预计未来生物质燃烧和沙尘活动的变化可能会增加这些数值，对区域生态系统和全球碳库产生影响。大气沉降对海洋溶解态黑碳库（DBC）的贡献尚不清楚。在此，作者表明水溶性黑碳与海洋气溶胶中的水溶性有机碳正相关，且大气沉降是海洋DBC的一个重要来源。
