Collaborative Research: Radiocarbon content of the Southwest Pacific and Southern Ocean waters in the Holocene and late Quaternary

摘要（Sikes/Guilderson 0823487/0823549）学术价值：由于海洋环流的变化在过去对气候产生了深刻的影响，这项研究解决了海洋环流在调节CO2中所起的基本作用。 这项工作使用新西兰沉积物中沉积的有孔虫测试中的放射性碳来研究全球海洋环流如何影响海洋和大气之间温室气体二氧化碳的分配。这项研究有两个主要目标：（1）重建南太平洋冰川的放射性碳特征，以证实或反驳存在一个足够古老的深水质量来解释冰川？大气CO2间冰期变化;（2）在冰川消退的不同时间间隔产生高分辨率的放射性碳记录，以提供全球CO2和放射性碳收支中缺少的南半球视角。 这些问题可以得到解决，因为海洋环流可以用放射性碳（14 C）追踪，因为大气中CO2气体的14 C含量与海洋中以溶解的碳酸盐和碳酸氢盐形式存在的14 C含量之间存在可量化的差异，这是因为在大气中的14 C和孤立水团中的14 C放射性衰变之间存在平衡平衡，温盐环流 这项研究利用了不同水深的近海取芯沉积物中火山岩层提供的精确地层控制。 将利用浮游和底栖有孔虫对建立海洋不同深度放射性碳的垂直剖面图，并收集一组氧同位素数据的时间序列，以跟踪浅水沃茨（600？2500米）和深沃茨（600- 4300米）通过时间的最后一个时期的冰川消退（17,500至9,500年前。美国和新西兰科学家之间的合作是美国研究人员与国际同行进行的重大投资外联活动，涉及加强研究基础设施的标准。该团队包括一名年轻的研究人员，没有事先获得NSF的资助，并在研究人员的机构之间交换了一名研究生，以解决推进培训和学习的标准。

ABSTRACT (Sikes/Guilderson 0823487/0823549)Intellectual merit: Because changes in ocean circulation have profoundly influenced climate in the past, this research addressed the fundamental role that ocean circulation plays in the regulation of CO2. The work uses radiocarbon in foraminifera tests deposited in sediments off New Zealand to examine how global ocean circulation affects the partitioning of the greenhouse gas CO2 between the ocean and atmosphere. This research has two primary goals: (1) to reconstruct the radiocarbon signature of the glacial southern Pacific to confirm or refute the presence of a deep water mass old enough to account for the glacial?interglacial changes in atmospheric CO2 and (2) to produce a high resolution record of radiocarbon at various intervals the time of deglaciation to provide a Southern Hemisphere perspective which is missing from global CO2 and radiocarbon budgets. These issues can be addressed because ocean circulation can be traced with radiocarbon (14C) because there is a quantifiable difference between the 14C content of atmospheric CO2 gas and that in the ocean where it exists in the form of dissolved carbonate and bicarbonate, This is because there is an equilibrium balance between 14C in the atmosphere and the radioactive decay of 14C in isolated water masses during thermohaline circulation. The research takes advantage of the precise stratigraphic control afforded by volcanic ask layers in cored off-shore sediments from different water depths. Planktonic and benthic foraminiferal pairs will be used to construct vertical profiles of radiocarbon at different depths in the ocean and a time series of set of oxygen isotope data will be collected to track the evolution of changes in shallow waters (600?2500 m) and deep waters (600-4300m) through the time of the last period of deglaciation (17,500 to 9,500 years ago. Broader impacts Collaborations among United States and New Zealand scientists represent significant investment outreach with international colleagues by US investigators addressing the criteria of enhancing infrastructure for research. The team includes a young investigator with no prior NSF funding and the exchange of a graduate student among the investigators' institutions, addressing criteria for advancing training and learning.