Wave Erosion at Ice Cliffs

冰崖的波浪侵蚀

• 批准号: 2148544
• 负责人: Till Wagner
• 金额: $ 62.22万
• 依托单位: University of Wisconsin-Madison
• 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: 2022-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2148544&HistoricalAwards=false
• 关键词: Wave; Erosion; Ice; Cliffs

The decay of ice shelves, glaciers, and icebergs greatly influences the polar environment, with far-reaching implications for the global climate and sea levels. A key driver of ice loss in the polar regions is the wave-induced erosion of icebergs, glaciers, and ice-shelf fronts. While rapid progress has been made in recent years in understanding a number of ice decay processes, wave erosion at the waterline of ice cliffs has not been studied in detail. This project will conduct an in-depth investigation of wave erosion in a laboratory setting, with the goal to provide new insight on how ice cliffs erode and improve the representation of these processes in large-scale ocean and climate simulations. The primary focus is on icebergs since wave erosion is most impactful in the open ocean environment. However, many of the findings will apply directly to glacier and ice-shelf fronts. In addition to its scientific significance, the project will train two graduate students at the forefront of climate science. A further aim is to construct a basic wave flume for educational purposes and involve K-12 teachers in the study through summer research experiences. How ice cliffs decay is one of the most ardently researched questions in the cryosphere. A key driver of ice loss that has garnered relatively little attention in this context is wave-induced erosion. Wave action at the sides of icebergs and at the fronts of water-terminating glaciers and ice shelves can cause ice loss in several ways: (i) Waves mix meltwater and ambient water, efficiently transport heat toward the ice, and accelerate melt at the waterline. (ii) The resultant incisions at the waterline can lead to failure of the overhanging ice cliff. (iii) The remaining submerged ice is buoyant, and the induced stresses can trigger full-depth calving events. This project aims to conduct the first detailed investigation of these processes in a laboratory setting, which will be used to guide new theoretical considerations and the development of a revised iceberg erosion parameterization to be implemented in comprehensive ocean models. The primary objectives of this work are two-fold: (1) To gain insight into the fundamental physics of wave erosion and derive theoretical relationships between melt rates and environmental conditions. (2) To develop a decay parameterization that accounts for the processes (i)-(iii) above with the aim to reduce the uncertainty associated with ice loss in model projections. This constitutes an important next step toward the larger goal of more accurate climate projections and improved estimates of future sea level rise.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.

冰架、冰川和冰山的衰退极大地影响着极地环境，对全球气候和海平面产生深远的影响。极地地区冰损失的一个关键驱动因素是波浪引起的冰山、冰川和冰架前沿的侵蚀。虽然近年来在理解一些冰的衰变过程方面取得了快速进展，但对冰崖水线处的波浪侵蚀尚未进行详细研究。该项目将在实验室环境中对波浪侵蚀进行深入调查，目的是提供有关冰崖侵蚀的新见解，并改善这些过程在大规模海洋和气候模拟中的表现。主要重点是冰山，因为波浪侵蚀在开阔的海洋环境中最具影响力。然而，许多发现将直接适用于冰川和冰架前沿。除了其科学意义外，该项目还将培养两名气候科学前沿的研究生。另一个目标是建造一个基本的波浪水槽用于教育目的，并通过夏季研究经验，让K-12教师参与研究。 冰崖如何衰变是冰冻圈中最热门的研究课题之一。在这种情况下，冰损失的一个关键驱动因素是波浪引起的侵蚀。在冰山的侧面和在水终止冰川和冰架的前部的波浪作用可以以几种方式导致冰损失：（i）波浪混合融水和环境水，有效地向冰输送热量，并加速水线处的融化。(ii)水线处产生的切口可能导致悬垂冰崖的破坏。(iii)剩余的水下冰是有浮力的，所产生的应力可以触发全深度的冰解作用。该项目的目的是在实验室环境中对这些过程进行首次详细调查，并将用于指导新的理论考虑和制定将在综合海洋模型中实施的经修订的冰山侵蚀参数化。本研究的主要目的有两个：（1）深入了解波浪侵蚀的基本物理过程，并推导出熔化速率与环境条件之间的理论关系。(2)制定一种衰变参数化方法，说明上述过程（一）-（三），目的是减少模型预测中与冰损失有关的不确定性。这是朝着更准确的气候预测和更好地估计未来海平面上升的更大目标迈出的重要一步。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。