Historic Perspectives on Climate and Biogeography from Deep-Sea Corals in the Drake Passage

Polar oceans are the main sites of deep-water formation and are critical to the exchange of heat and carbon between the deep ocean and the atmosphere. This award \"Historic perspectives on climate and biogeography from deep-sea corals in the Drake Passage\" will address the following specific research questions: What was the radiocarbon content of the Southern Ocean during the last glacial maximum and during past rapid climate change events? and What are the major controls on the past and present distribution of cold-water corals within the Drake Passage and adjacent continental shelves? Testing these overall questions will allow the researchers to better understand how processes in the Southern Ocean are linked to climate change over millennia. This award is being funded by the Antarctic Earth Sciences Program of NSF's Office of Polar Programs, Antarctic Division. INTELLECTUAL MERIT: The skeletons of deep-sea corals are abundant in the Southern Ocean, and can be dated using U-series techniques making them a useful archive of oceanographic history. By pairing U-series and radiocarbon analyses the awardees can reconstruct the radiocarbon content of seawater in the past, allowing them to address the research questions raised above. Collection of living deep-sea corals along with environmental data will allow them to address the broader biogeography questions posed above as well. The awardees are uniquely qualified to answer these questions in their respective labs via cutting edge technologies, and they have shown promising results from a preliminary pilot cruise to the area in 2008. BROADER IMPACTS: Societal Relevance: The proposed paleoclimate research will make significant advances toward constraining the Southern Ocean's influence on global climate, specifically it should help set the bounds for the upper limits on how fast the ocean circulation might change in this region of the world, which is of high societal relevance in this era of changing climate. Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating undergraduate through post-doctoral students into research programs; ii) promotion of K-12 teaching and learning programs by providing information via a cruise website and in-school talks, iii) making the data collected available to the wider research community via data archives such as Seamounts Online and the Seamount Biogeographic Network and iv) reaching a larger public audience through such venues as interviews in the popular media.极地海洋是深水形成（deep-water formation）的核心发生区域，对深海与大气间的热量及碳交换过程发挥关键作用。本资助项目「德雷克海峡（Drake Passage）深海珊瑚的气候与生物地理学历史研究视角」将聚焦两项具体研究问题：末次冰盛期（last glacial maximum）及过往快速气候变化事件期间，南大洋（Southern Ocean）的放射性碳（radiocarbon）含量状况如何？德雷克海峡及邻近大陆架（continental shelves）内冷水珊瑚（cold-water corals）过去与当前的分布格局主要受哪些因素调控？通过解答上述核心议题，研究团队可深入阐明南大洋的各类过程与数千年来气候变化的关联机制。本项目由美国国家科学基金会（National Science Foundation, NSF）极地项目办公室（Office of Polar Programs）南极分部（Antarctic Division）下属的南极地球科学项目（Antarctic Earth Sciences Program）资助。 **学术价值**：南大洋海域的深海珊瑚（deep-sea corals）骨骼资源丰沛，可通过铀系（Uranium-series）测年技术开展定年工作，是记录海洋学历史的优质档案载体。通过结合铀系与放射性碳分析手段，项目团队可重建过去海水的放射性碳含量记录，从而回应前文提出的研究问题。此外，采集活体深海珊瑚及配套环境数据的工作，也可助力其解答前文提出的广义生物地理学相关议题。项目团队凭借各自实验室的前沿技术体系，具备解答此类问题的独特资质，且其2008年前往该海域的先导科考航次已取得颇具前景的初步成果。 **拓展价值与社会影响**： 1. **社会相关性**：本项目拟开展的古气候（paleoclimate）研究，将在量化约束南大洋对全球气候的影响方面取得重要进展——具体而言，其可帮助确定该海域大洋环流变化速率的上限阈值。在当前气候变化的时代背景下，这一研究具备极高的社会关注度与应用价值。 2. **教育与拓展宣传（Education and Outreach, E/O）**：相关活动分为四大类别：① 通过将本科生至博士后阶段的研究人员全面纳入研究项目，提升学生群体参与极地研究的比例；② 通过科考航次专属网站与校内宣讲的方式，向K-12（幼儿园至12年级，即中小学阶段）教学活动提供相关科普信息，推广极地科学教育；③ 通过海山在线（Seamounts Online）、海山生物地理网络（Seamount Biogeographic Network）等数据归档平台，将采集到的数据集向更广泛的科研社区开放共享；④ 通过大众媒体访谈等渠道，向更广泛的公众群体传播研究成果。