Gao Xu-Xu, Qi Qian-Qian, Yang Gui-Peng
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China.
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
Mar Environ Res. 2025 Feb;204:106934. doi: 10.1016/j.marenvres.2024.106934. Epub 2024 Dec 26.
Dimethylsulfide (DMS) and very short-lived bromocarbons (VSL) are important biogenic trace gases emitted from oceans that can affect the global climate. Atmospheric deposition (AD) can provide nutrients and trace metals to the ocean, which can enhance primary productivity, but the complex effects of AD on DMS and VSL are still largely unexplored. A deck incubation experiment with aerosol additions was conducted to simulate the effects of acid-processed AD on the production of trace gases, including DMS and four VSL such as bromoform (CHBr), dibromomethane (CHBr), dibromochloromethane (CHBrCl), and bromodichloromethane (CHBrCl), in the oligotrophic western Pacific Ocean (WPO). During the incubation, the average concentrations of inorganic nitrates, DMS and VSL were significantly higher in the two aerosol treatments, indicating significant increases due to AD. Furthermore, the introduction of aerosols led to increases in the abundances of high DMS producers, specifically dinoflagellates, which contributed to the production of DMS. The acidified aerosol additions had a more pronounced influence on chlorophyll a and DMS, than non-acidified aerosol additions. However, the responses of VSL to the acidified aerosol treatment were more complex. The average CHBr and CHBr values showed no significant differences between these two aerosol treatments, while the values of CHBrCl and CHBrCl were significantly lower in the acidified aerosol treatment. These results illustrated that aerosol additions promoted the production of DMS and the four VSL. Nevertheless, the concentrations of CHBrCl and CHBrCl were suppressed in the acidified aerosol treatment relative to the non-acidified aerosol addition.
二甲基硫（DMS）和极短寿命溴代烃（VSL）是海洋排放的重要生物源微量气体，会影响全球气候。大气沉降（AD）可为海洋提供养分和痕量金属，从而提高初级生产力，但AD对DMS和VSL的复杂影响在很大程度上仍未得到充分研究。开展了一项添加气溶胶的甲板培养实验，以模拟酸处理后的AD对贫营养的西太平洋（WPO）中微量气体产生的影响，这些微量气体包括DMS以及四种VSL，如溴仿（CHBr₃）、二溴甲烷（CH₂Br₂）、二溴一氯甲烷（CHBr₂Cl）和一溴二氯甲烷（CHBrCl₂）。在培养期间，两种气溶胶处理中无机硝酸盐、DMS和VSL的平均浓度显著更高，表明因AD而显著增加。此外，气溶胶的引入导致高DMS生产者（特别是甲藻）的丰度增加，这促进了DMS的产生。酸化气溶胶添加对叶绿素a和DMS的影响比非酸化气溶胶添加更为显著。然而，VSL对酸化气溶胶处理的响应更为复杂。这两种气溶胶处理之间CHBr₃和CH₂Br₂的平均值没有显著差异，而在酸化气溶胶处理中CHBr₂Cl和CHBrCl₂的值显著更低。这些结果表明，添加气溶胶促进了DMS和四种VSL的产生。然而，相对于非酸化气溶胶添加，酸化气溶胶处理中CHBr₂Cl和CHBrCl₂的浓度受到抑制。
