Inverse Modeling of the Glacial Ocean

冰川海洋的反演模拟

• 批准号: 0524927
• 负责人: Olivier Marchal
• 金额: $ 35.8万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0524927&HistoricalAwards=false
• 关键词: Inverse; Modeling; Glacial; Ocean

Under this award the PIs will use an inverse modeling approach first pioneered by LeGrand and Wunsch (1995), to try to solve the origin of nutrient-rich waters below a depth of about 2.5 km in the Atlantic during the Last Glacial Maximum (around 21,000 years before present). This feature has been known for about two decades from measurements of d13C and Cd/Ca on fossil shells of benthic foraminifera. The inverse model will be used to test the validity of three possible mechanisms: a change in the deep circulation, a change in the nutrient concentration of the water mass end-members, and a change in the rates of organic matter remineralization at depth. Several critical extensions of the LeGrand and Wunsch will be undertaken: (i) the non-conservative character of the nutrients will be considered; (ii) benthic Cd/Ca and Zn/Ca data, in addition to benthic a 13C and a18O, will be incorporated; (iii) new benthic a13C data from the western Atlantic basin, which is a main flow path of deep waters, will be used; and (iv) the model domain will be extended to include the South Atlantic, where the nutrient proxy database has been largely improved since LW95.The project will include four major tasks: (I) a critical assessment of the existing nutrient proxy data, culminating with an estimate of the uncertainty of each datum; (II) the development of an inverse model of the circulation in the deep Atlantic; (III) the combination of the model with modern observations to test the model and to provide a reference state for hypothesis testing; and (IV) the combination of the model with data to test various hypotheses of nutrient enrichment in the glacial abyssal Atlantic. The project will involve a graduate student and a post-doc investigator and will contribute to fill the gap that exists today between the community of paleoceanographers and the community of physical oceanographers. It will bring together a modeler, a paleoceanographer and a physical oceanographer.

根据该奖项，PI 将使用 LeGrand 和 Wunsch（1995 年）首次提出的逆向建模方法，尝试解决末次盛冰期（大约 21,000 年）大西洋中约 2.5 公里深度以下营养丰富的水域的起源。几年前的现在）。 大约二十年来，人们通过对底栖有孔虫化石壳上 d13C 和 Cd/Ca 的测量了解了这一特征。 逆模型将用于测试三种可能机制的有效性：深层循环的变化、水团端员营养物浓度的变化以及深度有机质再矿化速率的变化。将进行 LeGrand 和 Wunsch 的几个关键扩展： (i) 将考虑营养素的非保守特性； (ii) 除了海底 a 13C 和 a18O 数据外，还将纳入海底 Cd/Ca 和 Zn/Ca 数据； (iii) 将使用来自西大西洋盆地（深水主要水流路径）的新底栖 a13C 数据； (iv) 模型领域将扩展到包括南大西洋，自 LW95 以来，该地区的营养物代理数据库已得到很大改进。该项目将包括四项主要任务：(I) 对现有营养物代理数据进行严格评估，最终对每个数据的不确定性进行估计； (II) 开发大西洋深海环流反演模型； （三）将模型与现代观测相结合来检验模型，为假设检验提供参考状态； (IV) 模型与数据相结合，检验大西洋深海冰川营养物富集的各种假设。该项目将涉及一名研究生和一名博士后研究员，并将有助于填补当今古海洋学家界和物理海洋学家界之间存在的空白。它将汇集一名建模师、一名古海洋学家和一名物理海洋学家。