Gas Tracers of Net Biological Oxygen Production in the Subtropical Pacific Ocean

副热带太平洋净生物产氧量气体示踪剂

• 批准号: 9617487
• 负责人: Steven Emerson
• 金额: $ 50.6万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-02-15 至 2000-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9617487&HistoricalAwards=false
• 关键词: Gas; Tracers; Net; Biological; Oxygen

9617487 Emerson Organic carbon export from the euphotic zone of the ocean regulates the CO2 content of the atmosphere and controls the redox balance in ocean chemistry on millenial time scales. One of the fundamental goals of oceanography is to evaluate the organic carbon flux and determine the controlling mechanisms so that system can be modeled well enough to predict responses to changes in forcing. Recent estimates of carbon export by a variety of methods at the U.S. JGOFS time-series stations indicate that the subtropical oceans are responsible for 25-50 percent of the global ocean new production. Progress in estimating the rate of new carbon export from the euphotic zone in the subtropical north Pacific Ocean now require knowledge of the mechanisms(s) controlling the supply rate of nutrients. Suggestions of diapycnal mixing, horizontal transport of dissolved organic matter, and various biological processes are currently being advanced. The implications of the different mechanisms regarding the coupling of the biological pump and ocean circulation are obvious and hold extremely important consequences for our understanding of the response of the ocean's "biological pump" to physical forcing. This study is designed to test the hypothesis that the mechanism supplying nutrients to the euphotic zone in the subtropical north Pacific is diapycnal transport. Focus will be on two main problems: (1) the role of intermittent transport in supplying nutrients necessary to create the shallow oxygen maximum, and (2) the utility of inert gases as tracers of diapycnal transport in the upper ocean. A fully instrumented deep-sea mooring will soon be deployed at the Hawaii Ocean Time-series (HOT) and can be used to make continuous measurements of oxygen and total gas pressure on the mooring to determine whether formation of the shallow O2 maximum is correlated to short-term intermittent supply of nutrients from below. ***

小行星9617487 海洋真光层的有机碳输出调节了大气中的CO2含量，并控制了千年时间尺度上海洋化学中的氧化还原平衡。 海洋学的基本目标之一是评估有机碳通量并确定控制机制，以便能够很好地模拟系统以预测对强迫变化的响应。 最近在美国JGOFS时间序列站通过各种方法对碳输出的估计表明，亚热带海洋占全球海洋新生产量的25%-50%。 在估算北太平洋亚热带真光层新的碳输出速率方面取得进展，现在需要了解控制营养物供应速率的机制。 目前正在提出一些建议，如底膜混合、溶解有机物的水平运输和各种生物过程。 关于生物泵和海洋环流的耦合的不同机制的影响是显而易见的，并且对于我们理解海洋的“生物泵”对物理强迫的响应具有极其重要的后果。 本研究旨在检验北太平洋副热带真光层营养物质的供应机制是透气旋输送的假说。 重点将放在两个主要问题上：（1）间歇性输送在提供产生浅水氧最大值所必需的营养物方面的作用，以及（2）惰性气体作为上层海洋中的穿膜输送示踪剂的效用。 不久将在夏威夷海洋时间序列（HOT）部署一个全仪表化深海系泊系统，可用于连续测量系泊系统上的氧气和总气压，以确定浅层O2最大值的形成是否与来自下方的营养物的短期间歇供应有关。 ***