Collaborative Research: Elucidating the Ocean Dynamics Governing Melt at Glaciers Using Lagrangian Floats

合作研究：利用拉格朗日浮标阐明控制冰川融化的海洋动力学

• 批准号: 2319495
• 负责人: Trevor Harrison
• 金额: $ 81.9万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2319495&HistoricalAwards=false
• 关键词: Collaborative; Research; Elucidating; Ocean; Dynamics

The proposed study will determine the physical processes that cause melting at an Alaskan glacier that ends in a fjord. The study will try to prove whether recirculating cells and waves below the sea-surface cause stronger velocities than the flows associated with melting glaciers. The project will develop instruments that drift in three dimensions, capable of drifting along a fixed depth or move with a water type. These drifting instruments will be combined with instrumentation that is fixed at one place and with ship measurements, and with computer models to decipher the interactions of different three-dimensional motions at the glacier face; and to resolve the time and space structure of flows that enhance heat flux to, and melting of, the glacier. Understanding of these processes shall allow projections of glacier mass loss and resulting melt-water flux into the polar oceans. As Broader Impacts, the study will help in global-scale formulations of submarine glacial melting. The Principal Investigator is an early career investigator, as well as two of the Co-PIs. The project will support a couple of graduate students.The proposed work will characterize the processes that drive near-glacier circulation and submarine glacial melt at LeConte Glacier, Alaska. The hypothesis is that accelerated glacier melting results from different-scale recirculations and internal waves at the glacier face that are not included in standard ocean-model parameterizations of glacial melt; and that these recirculations and internal wave motions overwhelm the plume velocities. The hypothesis will be tested via development of microfloats (µfloats) that drift in 3D, capable of drifting along a fixed depth or move with water (an isopycnal surface). The study will use acoustically tracked Lagrangian µfloats, mooring and vessel observations, and numerical modeling to elucidate the interplay of: (1) entrainment and recirculation driven by discharge plumes; (2) internal waves and their contributions to vertical velocity at the glacier face; and (3) the spatiotemporal structure of lateral circulations believed to enhance heat flux to the glacier. These processes shall allow projections of glacier mass loss and resulting melt-water flux into the polar oceans. High-resolution numerical simulations will inform deployments and be used to synthesize results. As Broader Impacts, the study will inform parametrizations of submarine melting. The PI and two Co-PIs are early career investigators, and the project will support a couple of graduate students.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.

拟议的研究将确定导致在峡湾结束的阿拉斯加冰川融化的物理过程。该研究将试图证明循环细胞和海面下方的波是否比与熔融冰川相关的流量会导致更强的速度。该项目将开发在三个维度上漂移的仪器，能够沿固定深度行驶或使用水类型移动。这些驾驶仪器将与固定在一个地方和船舶测量的仪器结合在一起，并使用计算机模型来破译冰川面部不同三维运动的相互作用；并解决冰川的热通量和熔化的流量的时间和空间结构。对这些过程的理解应允许冰川质量损失和导致的熔融水的预测到极地海洋。随着更广泛的影响，这项研究将有助于实现海底冰川融化的全球规模公式。首席调查员是早期职业研究员，也是两个共同研究人员。该项目将支持几个研究生。拟议的工作将描述阿拉斯加Leconte冰川近距离冰川圈和海底冰川融化的过程。假设是，冰川面的不同尺度再循环和内部波的加速冰川熔融导致，这些冰川面部未包含在冰川融化的标准海洋模型参数中。这些再循环和内波动运动不堪重负。该假设将通过在3D中漂移的微韧带（µFloats）的开发进行检验，能够沿固定深度驱动或用水（等轴表面）移动。该研究将使用准确跟踪的拉格朗日粉，系泊和血管观测以及数值建模来阐明以下相互作用：（1）通过排放羽流的入口和再循环驱动器； （2）内部波及其对冰川面上垂直速度的贡献； （3）横向循环的空间时间结构被认为会增强冰川的热通量。这些过程应允许投影冰川质量损失，并导致熔融水的通量进入极地海洋。高分辨率数值模拟将为部署提供信息，并用于综合结果。随着更广泛的影响，该研究将为潜艇熔化的参数提供信息。 PI和两个Co-Pis是早期的职业调查人员，该项目将支持几位研究生。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响评估标准，认为通过评估被认为是珍贵的支持。