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

9617487艾默生有机碳从海洋的真光区输出，调节大气中的二氧化碳含量，并在千年时间尺度上控制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，以便能够对系统进行足够好的建模，以预测对强迫变化的响应。最近对美国JGOFS时间序列站各种方法碳输出的估计表明，亚热带海洋占全球海洋新产量的25%-50%。在估计北太平洋亚热带真光层新碳输出速率方面的进展，现在需要了解控制营养物质供应速率的机制(S)。关于昼夜混合、溶解有机物质的水平运输和各种生物过程的建议目前正在推进。关于生物泵和海洋环流耦合的不同机制的影响是显而易见的，对于我们理解海洋的“生物泵”对物理强迫的反应具有极其重要的后果。这项研究旨在检验一种假设，即向副热带北太平洋真光带提供营养物质的机制是昼夜运输。重点将放在两个主要问题上：(1)间歇输送在提供创造浅层氧气最大值所需营养物质方面的作用，以及(2)利用惰性气体作为上层海洋昼夜输送的示踪剂。一台全仪表化的深海系泊设备将很快部署在夏威夷海洋时间序列(HOT)上，并可用于连续测量系泊设备上的氧气和总气体压力，以确定浅层氧气最大值的形成是否与来自下方的短期间歇营养物质供应有关。***

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. ***