Development and application of seawater nutrient proxies in deep-sea corals

重建过去中深水的营养物质浓度是古海洋学研究的一个重要目标。这些信息将使我们能够计算出平流活跃地区（例如大西洋）的中深水质量混合比，并与放射性碳定年法相结合，将得出通风率，通风率被认为是对大气CO2的重要控制。过去的养分分布也可以提供有关循环较慢地区的生产力和再矿化的信息。该奖项支持了对深海独居珊瑚石竹中营养盐磷酸盐（P/Ca）和准营养盐钡（Ba/Ca）的古代用物的改进和应用。该研究将使用活体收集的珊瑚为南大洋提供一个区域代理校准，然后将分析化石标本，以确定自末次盛冰期以来南部水源水营养成分的演变。他们还将利用新英格兰海底山的年代久远的珊瑚化石，重建过去30天西北大西洋中深水区营养物质浓度的历史。该研究将为过去海洋的营养分布提供一种新的定量评估。这项工作是加州理工学院和伦敦帝国理工学院的科学家们共同努力的一部分，他们将提供样本材料和补充数据。更广泛的影响包括资助一名女博士生，以及与罗格斯大学建立良好的COSEE（海洋科学卓越教育中心）项目合作的外展努力。

Reconstruction of nutrient concentrations in past intermediate and deep waters is a critical goal in paleoceanography. Such information will allow calculation of intermediate/deep water mass mixing ratios in areas of active advection (e.g., the Atlantic), and when combined with radiocarbon dating will yield ventilation rates, which are thought to be an important control on atmospheric CO2. Past nutrient distributions can also yield information about productivity and remineralization in areas of more sluggish circulation. This award supports refinement and application of paleo-proxies for the nutrient phosphate (P/Ca) and the quasi-nutrient barium (Ba/Ca) in the solitary deep-sea coral D. dianthus. The research will produce a regional proxy calibration for the Southern Ocean using live-collected corals, and will then analyze fossil specimens to determine the evolution of endmember Southern source water nutrient content since the Last Glacial Maximum. They will also reconstruct the history of nutrient concentrations at mid to deep water depths in the NW Atlantic over the past 30ky using dated fossil corals from the New England seamounts. The research will provide a new, quantitative assessment of nutrient distribution in the past ocean. This work is part of a larger collaborative effort involving scientists from CalTech and Imperial College, London, who will provide both sample material and complementary data. Broader impacts include funding of a female PhD student as well as outreach efforts in association with the well-established COSEE (Center for Ocean Sciences Education Excellence) program at Rutgers University.