Application of Transient Time Distributions to Ocean Radiocarbon Records for the Last Deglaciation

瞬态时间分布在末次冰消期海洋放射性碳记录中的应用

• 批准号: 1301907
• 负责人: Olivier Marchal
• 金额: $ 51.74万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1301907&HistoricalAwards=false
• 关键词: Application; Transient; Time; Distributions; Ocean

Radiocarbon (14C) is an important tracer of ocean circulation. However, although extensive marine Delta14C records have been developed, quantitative interpretations of these records are lacking. The proposed work, led by researchers at Woods Hole Oceanographic Institution, will take a novel, quantitative approach to Delta14C records of deep and surface waters from the last deglaciation. The project will generate an up-to-date compilation of Delta14C records with associated uncertainty estimates. Transit time distribution (TTD) calculations will be applied to these records to relate deepwater Delta14C concentrations to those in surface waters. Specifically, TTDs derived from modern hydrographic data will be used to compute the changes in deepwater Delta14C that are implied by the surface water records, and vice versa. This approach will test the hypothesis that steep declines in deep and surface water Delta14C values during the last deglaciation were jointly driven by a change in ocean ventilation. This project will unite the expertise of an ocean modeler, a physical oceanographer, and a paleoceanographer to address a key question about ocean circulation during conditions of deglaciation. A graduate student will be involved in the research, and summer support for an undergraduate student will be provided. Project data, computational software, and accompanying "how-to" documentation will be archived at NOAA's National Climatic Data Center.

放射性碳（14C）是海洋循环的重要示踪剂。但是，尽管已经开发了广泛的海洋多核Delta14c记录，但缺乏对这些记录的定量解释。由伍兹霍尔海洋学院（Woods Hole Oceanographic）研究人员领导的拟议作品将采用一种新颖的定量方法，以从上一次脱位中进行深层和地表水记录。该项目将生成Delta14c记录的最新汇编，并具有相关的不确定性估计。运输时间分布（TTD）计算将应用于这些记录，以将深水Delta14c浓度与地表水中的浓度相关联。具体而言，从现代水文数据中得出的TTD将用于计算地表水记录所暗示的深水Delta14c的变化，反之亦然。这种方法将检验以下假设：在最后一次脱气过程中，深层和地表水的急剧下降是由海洋通风的变化共同驱动的。该项目将团结一位海洋建模者，物理海洋学家和古文学学家的专业知识，以解决有关脱气条件下海洋循环的关键问题。研究生将参与研究，并将提供对本科生的夏季支持。项目数据，计算软件和随附的“操作方法”文档将在NOAA的国家气候数据中心存档。