Evolution of Glacial Meltwater in the North Atlantic Current - Subpolar Front System

北大西洋洋流-副极锋系统中冰川融水的演化

• 批准号: 2202771
• 负责人: Olivier Marchal
• 金额: $ 44.96万
• 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: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2202771&HistoricalAwards=false
• 关键词: Evolution; Glacial; Meltwater; North; Atlantic

The melting of the great ice sheets of the last Ice Age caused sea level to rise by about 130 m globally. In this project a computer model will be developed to simulate the pathways of glacial water introduced into the North Atlantic Ocean from the Laurentide Ice Sheet – the great ice sheet that covered northern North America during the last Ice Age. The project will include modeling of small-scale eddies and their influence on glacial water movements which will help in the understanding of the ocean’s response to ice sheet changes. The results will be important for understanding the role of glacial waters released today from other ice sheets such as the Greenland Ice Sheet. The project will support a graduate student and three undergraduate students, and a how-to manual will be produced so that scientists can use or adapt the model for other projects.A numerical model which represents ocean circulation and sea ice and which resolves ocean mesoscale eddies will be developed to produce detailed simulations of the evolution of glacial water in the North Atlantic Current-Subpolar Front system. Focus will be on glacial meltwater which emanated from the Laurentide Ice Sheet at different locations along the Labrador Shelf, where evidence for ice streams delivering material into the sub-polar gyre exists, and through Fram Strait, which will allow representation of a source of meltwater from the Arctic Ocean, and in particular the Mackenzie River. Two questions will be addressed: (1) To which extent are the temperature and salinity of glacial waters modified as they flow towards deep-water formation areas in the northern North Atlantic? (2) Which processes (eddy-induced mixing or air-sea interactions) most effectively modify the properties of glacial waters en route to these areas? The work plan to address these questions is threefold. First, a coupled ocean circulation-sea-ice model will be configured to represent the subpolar North Atlantic. Second, the coupled model will be tested by using modern observations from oceanographic cruises, hydrographic climatologies, and satellite missions. Finally, experiments with the coupled model will be conducted and analyzed to quantify the erosion of glacial water properties en route to deep-water formation regions and evaluate the role of different eroding factors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

最后一个冰河时代的大冰盖融化导致全球海平面上升约130米。在这个项目中，将开发一个计算机模型来模拟从劳伦泰德冰盖（Laurentide Ice Sheet）进入北大西洋的冰川水的路径，劳伦泰德冰盖是上一个冰河时代覆盖北美北方的大冰盖。该项目将包括模拟小规模漩涡及其对冰川水运动的影响，这将有助于了解海洋对冰盖变化的反应。这一结果对于理解今天从格陵兰冰盖等其他冰盖释放的冰川沃茨的作用将是重要的。该项目将资助一名研究生和三名本科生，并将编制一份操作手册，以便科学家能够将该模式用于或调整该模式用于其他项目。将开发一个代表海洋环流和海冰并解决海洋中尺度涡旋的数值模式，以详细模拟北大西洋洋流-副极地锋系统中冰川水的演变。重点将放在从拉布拉多大陆架沿着不同地点的劳伦蒂德冰盖散发的冰川融水上，那里有冰流将物质输送到次极地环流的证据，并通过弗拉姆海峡，这将使人们能够代表北冰洋融水的来源，特别是麦肯齐河。将解决两个问题：（1）在何种程度上是冰川沃茨的温度和盐度的修改，因为它们流向深水形成地区在北大西洋北方？(2)哪些过程（涡流引起的混合或海气相互作用）最有效地改变了冰川沃茨在通往这些地区的途中的性质？解决这些问题的工作计划有三个方面。首先，一个耦合的海洋环流海冰模型将被配置为代表副极地北大西洋。第二，将利用海洋学巡航、水文气候学和卫星任务的现代观测结果对耦合模型进行测试。最后，将进行与耦合模型的实验和分析，以量化冰川水属性的侵蚀途中深水形成区域和评估的作用，不同的侵蚀factors.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。