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: 2319494
• 负责人: Jesse Cusack
• 金额: $ 126.39万
• 依托单位: Oregon State University
• 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=2319494&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终止于峡湾的阿拉斯加冰川融化的物理过程。该研究将试图证明海面以下的循环细胞和波浪是否会产生比冰川融化相关的流动更快的速度。三维漂流仪器，能够沿固定深度漂流或随水型移动这些漂流仪器将与固定在一处的仪器和船舶测量相结合，并与计算机模型相结合。破译冰川表面不同三维运动的相互作用；并解决增强冰川热通量和融化的流动的时间和空间结构。作为更广泛的影响，该研究将有助于全球范围内海底冰川融化的制定。该项目的首席研究员是一名早期职业研究员。支持几名研究生。拟议的工作将描述阿拉斯加勒孔特冰川驱动近冰川环流和海底冰川融化的过程。假设是冰川加速融化是由冰川表面不同规模的再循环和内波造成的。不包括在冰川融化的标准海洋模型参数化中；并且这些再循环和内部波浪运动压倒了羽流速度。 3D 漂移的微浮体（μfloats），能够沿着固定深度漂移或随水移动（等密度表面）。该研究将使用声学跟踪的拉格朗日μfloats、系泊和船只观测以及数值模型来阐明以下因素之间的相互作用：（ 1）由排放羽流驱动的夹带和再循环；（2）内波及其对冰川表面垂直速度的贡献；横向环流的时空结构被认为可以增强冰川的热通量，这些过程将允许预测冰川质量损失和由此产生的融化水通量进入极地海洋，这将为部署提供信息并用于综合结果。更广泛的影响，该研究将为潜艇熔化的参数化提供信息 PI 和两名 Co-PI 都是早期职业调查员，该项目将支持几名研究生。该奖项反映了 NSF 的法定使命。通过使用基金会的智力优点和更广泛的影响审查标准进行评估，并被认为值得支持。