Intermediate Water Records of Radiocarbon and Temperature Variability from the North Atlantic and Southern Ocean Using Deep-Sea Corals.

使用深海珊瑚记录北大西洋和南大洋的放射性碳和温度变化的中间水记录。

• 批准号: 1204211
• 负责人: Jess Adkins
• 金额: $ 47.21万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1204211&HistoricalAwards=false
• 关键词: Intermediate; Water; Records; Radiocarbon; Temperature

Radiocarbon is a well-established tool for understanding past changes in ocean circulation and climate. However, recent studies of radiocarbon from intermediate water depths (~500 to 2,000 meters below sea level) have produced conflicting accounts of ocean behavior during the transition from the Last Glacial Maximum (LGM) to the Holocene. This project, led by a professor at the California Institute of Technology, seeks to resolve this problem by generating a new intermediate-depth radiocarbon record for the last 30,000 years using fossil deep-sea corals from the North Atlantic and Southern Oceans. A key advantage of this approach over measurements of plankton in sediment cores is the opportunity for uranium-series age control. Furthermore, fossil coral samples enable the collection of high-resolution measurements during key periods in the deglacial transition. For a subset of samples, proxy temperature data (from clumped isotopes) will be compared to radiocarbon content in order to better resolve changes in intermediate and deep water mass characteristics. Simple models will be used to provide a quantitative framework for the results of data analyses.This study will advance understanding of the role of ocean circulation in climate change on glacial time scales. Samples will be made broadly available through the developing CalTech deep-sea coral database, which is already in use by scientists from around the world. The investigator will continue collaboration with NOSAMS (National Ocean Sciences Mass Spectrometry Facility) to develop rapid and inexpensive techniques for radiocarbon dating of corals and other carbonates. The investigator will also continue ongoing climate science outreach efforts for local schools and organizations, as well as the broader public. Funding will support a female graduate student.

放射性碳是了解过去海洋环流和气候变化的成熟工具。然而，最近对中等水深(海平面以下约500米至2000米)的放射性碳的研究，对从末次冰盛期(LGM)向全新世过渡期间的海洋行为产生了相互矛盾的描述。该项目由加州理工学院的一名教授领导，试图通过使用北大西洋和南大洋的深海珊瑚化石来产生过去3万年来新的中深度放射性碳记录，从而解决这个问题。与测量沉积物岩心中的浮游生物相比，这种方法的一个关键优势是有机会进行铀系列年龄控制。此外，化石珊瑚样本能够在退冰期过渡的关键时期收集高分辨率的测量数据。对于样本的一个子集，将把代理温度数据(来自成束的同位素)与放射性碳含量进行比较，以便更好地解决中深层水团特征的变化。将使用简单的模型为数据分析结果提供量化框架。这项研究将在冰川时间尺度上促进对海洋环流在气候变化中的作用的理解。样本将通过加州理工学院正在开发的深海珊瑚数据库广泛提供，该数据库已经被世界各地的科学家使用。研究人员将继续与国家海洋科学质谱仪(NOSAMS)合作，开发对珊瑚和其他碳酸盐进行放射性碳测年的快速和廉价技术。调查员还将继续为当地学校和组织以及更广泛的公众进行气候科学外联工作。资金将用于资助一名女研究生。