Collaborative Research: The Biogeochemistry of Dimethylsulfied (DMS) and Related Compounds in a Chemically Stratified Antarctic Lake

合作研究：化学分层南极湖中二甲硫 (DMS) 和相关化合物的生物地球化学

• 批准号: 9815998
• 负责人: John Priscu
• 金额: $ 24.77万
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9815998&HistoricalAwards=false
• 关键词: Collaborative; Research; Biogeochemistry; Dimethylsulfied; DMS

OPP 98-15998 P.I. J. PriscuOPP98-18140 P.I. G. DiTullioDimethylsulfide (DMS) is the dominant volatile sulfur compound emitted from the ocean and may represent up to 90% of the sea-to-air biogenic sulfur flux. It has been hypothesized that cloud formation caused by condensation nuclei associated with products of DMS oxidation can directly counteract warming effects of anthropogenically produced CO2. Despite the global importance of DMS and related sulfonium compounds, and the significant role of aquatic systems in DMS production (particularly in south polar regions), the sources and sinks of DMS and associated sulfonium compounds remain equivocal. Our proposed multi-investigator field and laboratory research will examine the biogeochemistry of water column and sedimentary DMS/DMSP (dimethylsulfoniopropionate), and the role of associated compounds (e.g. dimethylsulfoxide, dimethylated polysulfides) in Lake Bonney. Lake Bonney is a relatively simple (no turbulence, no grazers and little atmospheric exchange) aquatic system and therefore provides a highly tractable environment for investigating microbially mediated cycling of biogenic sulfur. Preliminary data suggest that maximum levels of DMS precursors occur in the deep-chlorophyll layer of the lake, a zone dominated by cryptophyte algae. In addition, DMS concentrations in the aphotic waters of Lake Bonney are among the highest recorded in a natural aquatic system. These observations indicate that precursors produced by trophogenic zone phytoplankton sink to the aphotic waters and sediments where they are microbially decomposed to DMS and other sulfur compounds. The proposed research will define the sources and sinks of DMS and associated compounds and relate them to overall ecosystem function. A model of biogeochemical transformations of organo-sulfur compounds in Lake Bonney will be developed.

OPP 98-15998 P.I.J.PriscuOPP98-18140 P.I.G.二叔丁基二甲基硫化物(DMS)是海洋排放的主要挥发性硫化物，占海-气生物硫通量的90%以上。据推测，DMS氧化产物的凝结核形成的云可以直接抵消人类产生的二氧化碳的变暖效应。尽管二甲基硫和相关的硫化物具有全球重要性，而且水生系统在二甲基硫的生产中发挥着重要作用(特别是在南极地区)，但二甲基硫和相关的硫化物的来源和汇仍然不明确。我们拟议的多调查者现场和实验室研究将研究邦尼湖水柱和沉积物DMS/DMSP(二甲基硫代丙酸盐)的生物地球化学，以及伴生化合物(例如二甲基亚砜、二甲基多硫化物)的作用。邦尼湖是一个相对简单的水生系统(没有湍流，没有食草动物，几乎没有大气交换)，因此为研究微生物介导的生物硫循环提供了一个非常容易处理的环境。初步数据表明，DMS前体的最大水平出现在湖泊的深层叶绿素层，这是一个以隐芽藻类为主的区域。此外，邦尼湖无光水域中的DMS浓度是自然水系中有记录以来最高的。这些观察表明，营养带浮游植物产生的前体沉没到无温水域和沉积物中，在那里它们被微生物分解为DMS和其他含硫化合物。拟议的研究将确定DMS和相关化合物的源和汇，并将它们与整体生态系统功能联系起来。将建立邦尼湖有机硫化合物的生物地球化学转化模型。