Historical Simulations of Greenland Ice-sheet Dynamics: The Imprint of Early Ice Loss on Recent and Future Change

格陵兰冰盖动力学的历史模拟：早期冰损对近期和未来变化的影响

• 批准号: 2315686
• 负责人: John Erich Christian
• 金额: $ 36.18万
• 依托单位: Georgia Tech Research Corporation
• 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: 2023-08-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2315686&HistoricalAwards=false
• 关键词: Historical; Simulations; Greenland; Ice; sheet

Ice loss from the Greenland Ice Sheet contributes to sea level rise and is projected to continue over the next century. Projections of future ice loss rely on models that simulate the dynamic response of the ice sheet to climate changes. A key challenge is calibrating models based on observations made in the last few decades, in part because ice dynamics adjust to climate changes over long timescales. Past climate therefore affects the modern state. This project will use a numerical ice-sheet model and long-term climate data to simulate Greenland ice-sheet changes since 1850, with a specific focus on the ice-sheet’s dynamic “memory” of climate over the past century. Ice loss concurrent with rapid warming is well documented in recent decades, but a period of rapid Arctic warming also occurred in the 1920s-1930s. Historical observations, where available, suggest that this triggered the retreat of many glaciers on the Greenland Ice Sheet, but their ongoing adjustment has not been thoroughly investigated. With simulations that fully encompass this period of early climate forcing, this project will provide further context for recent observations, and will provide insights that will aid in calibrating models for future projections. This project will also train two undergraduate students.The model simulations will encompass both the Greenland Ice Sheet as a whole, as well as case studies on several of its major outlet glaciers. Simulations will be forced with climate reanalysis products that extend over the industrial era, enabling a realistic treatment of short-term variability, including the rapid warming of the 1920s-1930s. The primary intended deliverable will be historical simulations that capture the major phases of mass loss suggested by long-term observations. Model output will be made publicly available to aid broader efforts to initialize simulations of future mass loss of the Greenland Ice Sheet. An additional deliverable will be a set of perturbed simulations designed to clarify leading physical controls on the glacier and ice-sheet evolution over this era. This will include assessing the relative impacts of climate variability and topographic boundary conditions, and the dynamic response that was committed by early-twentieth-century climate forcing. Together, the proposed model simulations will test theory and quantify the effects of early forcing, drawing new links between sparse glacier and climate observations from the pre-satellite era.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.

格陵兰冰盖的冰损失导致海平面上升，预计未来冰损失的预测依赖于模拟冰盖对气候变化的动态响应的模型。基于过去几十年的观测，部分原因是冰动态会在很长一段时间内适应气候变化，因此会影响现代状态。该项目将使用数值冰盖模型和长期气候数据来模拟格陵兰冰。 - 工作表更改自1850 年，特别关注冰盖对上个世纪气候的动态“记忆”。近几十年来，冰盖流失与快速​​变暖的情况已有充分记录，但北极快速变暖的时期也发生在 1920 年代至 1930 年代。历史观察表明，这引发了格陵兰冰盖上许多冰川的退缩，但该项目尚未对它们正在进行的调整进行彻底的研究，因为模拟完全涵盖了这一时期的早期气候强迫。将为最近的观测提供进一步的背景，并将提供有助于校准未来预测模型的见解。该项目还将培训两名本科生。模型模拟将涵盖整个格陵兰冰盖以及案例研究。将使用跨越工业时代的气候再分析产品对其几个主要出口冰川进行模拟，从而能够现实地处理短期变化，包括 1920 年代至 1930 年代的快速变暖。可交付成果将是历史模拟，捕捉长期观测所表明的质量损失的主要阶段，将提供模型输出，以帮助更广泛的努力，以公开公开模拟格陵兰岛未来的质量损失。一组扰动模拟旨在阐明这一时期对冰川和冰盖演化的主要物理控制，这将包括评估气候变化和地形边界条件的相对影响，以及二十世纪初的动态响应。气候强迫。总之，所提出的模型模拟将测试理论并量化早期强迫的影响，在稀疏冰川和前卫星时代的气候观测之间建立新的联系。该奖项授予 NSF 的法定使命，并通过使用基金会的评估进行评估，被认为值得支持。智力价值和更广泛的影响审查标准。