US GEOTRACES N. Atlantic: Measuring the δ13C-DIC distribution and quantifying the impact of organic matter export on δ13C, nutrients and biologically active trace

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。在这个项目中，华盛顿大学的研究人员将解决GEOTRACES项目的两个最重要的目标：推进我们对控制海洋中微量元素分布的过程的理解，以及理解控制用于替代过去海洋环境的地球化学物种浓度的过程。总体目标是提高我们使用微量元素和del13C代用物作为过去海洋环流和碳循环变化指标的能力。本研究分为三个部分：(1)测量北大西洋GEOTRACES巡航期间溶解无机碳（DIC）的13C/12C；(2)估算表层有机质输出速率；(3)量化海气CO2气体交换、OM输出、再矿化和环流对大西洋生物活性微量元素、del 13C-DIC和营养物质现代分布的影响。Del13C-DIC将在所有站点测量总共约600个样本，特别强调提高中间水域和深海的采样覆盖率。此外，该团队将使用离散的和正在进行的测量来测量表层溶解的O2/Ar气体比例。OM出口比率将通过两种方法确定。第一种方法依赖于ä13C-DIC的海气不平衡；第二种方法依赖于溶解氧气体的海气不平衡。海气交换速率将根据卫星风速估算。这部分项目的目标是提高我们对OM出口对生物活性微量元素的影响的理解。更广泛的影响。该项目是一个国际科学计划（GEOTRACES）的一部分，因此，数据和研究成果将广泛分发给国际海洋学界。此外，研究结果将纳入首席研究员的教学课程，特别是在名为“极端气候”的本科课程和名为“同位素生物地球化学”的研究生课程中。第三，在本项目中，本科生将积极参与del13C-DIC分析样品的制备。最后，GEOTRACES项目的目标有明显的社会效益，它将在大气二氧化碳浓度增加的情况下改善对未来气候变化的预测。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).In this project, researchers at the University of Washington will address two of the overriding goals of the GEOTRACES program: advancing our understanding of the processes that control trace element distributions in the ocean, and understanding the processes that control the concentrations of geochemical species used for proxies of the past ocean environment. The overall goal is to improve our ability to use trace element and del13C proxies as indicators of past changes in ocean circulation and carbon cycling. The research has three components: (1) to measure the 13C/12C of the dissolved inorganic carbon (DIC) during the GEOTRACES cruise in the North Atlantic Ocean; (2) to estimate the rate of organic matter (OM) export from the surface layer; and (3) to quantify the impact that air-sea CO2 gas exchange, OM export, remineralization and circulation have on the modern distributions of bioactive trace elements, del 13C-DIC and nutrients in the Atlantic Ocean. Del13C-DIC will be measured at all stations for a total of ca. 600 samples with particular emphasis on improving the sampling coverage in intermediate waters and deep sea. Additionally, the team will measure the dissolved O2/Ar gas ratio in the surface layer using discrete and underway measurements. The rates of OM export will be determined using two approaches. The first method relies on the air-sea disequilibrium of the ä13C-DIC; the second method relies on the air-sea disequilibrium of the dissolved oxygen gas. Air-sea gas exchange rates will be estimated from satellite-based wind speeds. The goal of this part of the project is to improve our understanding of the impact of OM export on bioactive trace elements. Broader Impacts. This project is part of an international scientific program (GEOTRACES) and, thus, the data and research results will be broadly distributed to the international oceanographic community. Additionally, the results will be incorporated into the principal investigator's teaching curricula, specifically in an undergraduate course entitled Climatic Extremes and graduate course entitled Isotope Biogeochemistry. Third, there will be active undergraduate participation in preparing samples for del13C-DIC analyses during this project. Lastly, there are clear societal benefits from the GEOTRACES program goals that will improve predictions of future climate change under increasing atmospheric CO2 levels.