Methan oxidation in the water column and its role in the carbon budget of the coastal ocean

水体中的甲烷氧化及其在沿海海洋碳预算中的作用

• 批准号: 16707631
• 负责人: Dr. Susan Mau
• 金额: --
• 依托单位: Department of Earth Science
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2005-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/16707631?language=en
• 关键词: Methan; oxidation; water; column; its

The release of large amounts of the greenhouse gas methane from marine gas reservoirs is believed to have advanced warming episodes in Earth¿s history. However, methane emitted at the seafloor is consumed partly in the ocean by microorganisms, reducing the portion reaching the atmosphere. The main purpose of this project is to quantify the fraction of CH4 oxidized in the water column in relation to the amount discharging, dispersed in the water column and escaping into the atmosphere at different seep settings. For that purpose, the proposer will learn the 14C/3H-tracer technique including the synthesis of the tracers at the University of California, Santa Barbara (UCSB), USA, and apply this technique to measure oxidation rates of CH4 in the water column. The acquired technique will be ideally complemented by CH4 concentration analyses in the water column, ocean current measurements, mapping of bubble plumes, and gas analyses at the sea surface. These investigations will be performed at several vent sites situated in the Santa Barbara Basin/Channel of California in close cooperation with the SEEPS project at the UCSB. The area is ideally suited as it is one of the most active areas of natural marine hydrocarbon seepage in the world. The comparison of results from distinct vent sites will provide new insight to the buffer system of the ocean with regard to hydrocarbon seepage. This is of great value for the assessment of the climatological response of a sudden release of CH4 from marine gas resources.

据信，海洋气藏释放出的大量温室气体甲烷导致了地球历史上的变暖事件。然而，海底排放的甲烷部分在海洋中被微生物消耗，减少了到达大气的部分。该项目的主要目的是量化水柱中氧化的 CH4 比例与在不同渗流设置下排放、分散在水柱中并逃逸到大气中的量之间的关系。为此，提案者将在美国加州大学圣塔芭芭拉分校（UCSB）学习14C/3H示踪剂技术，包括示踪剂的合成，并应用该技术测量水柱中CH4的氧化速率。所获得的技术将得到水柱中甲烷浓度分析、洋流测量、气泡羽流绘图和海面气体分析的理想补充。这些调查将与 UCSB 的 SEEPS 项目密切合作，在位于加利福尼亚州圣巴巴拉盆地/海峡的几个喷口点进行。该地区非常适合，因为它是世界上天然海洋碳氢化合物渗漏最活跃的地区之一。对不同喷口位置的结果进行比较将为了解海洋缓冲系统在碳氢化合物渗漏方面提供新的见解。这对于评估海洋天然气资源CH4突然释放的气候响应具有重要价值。