Collaborative Research: Understanding mechanisms of projected 21st century ocean warming around Greenland

合作研究：了解格陵兰岛周围预计 21 世纪海洋变暖的机制

• 批准号: 1513396
• 负责人: Christopher Little
• 金额: $ 45.07万
• 依托单位: Atmospheric and Environmental Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1513396&HistoricalAwards=false
• 关键词: Collaborative; Research; Understanding; mechanisms; projected

Devastating storm surges result from a combination of the characteristics of the storm itself; e.g. wind strength, direction of storm approach to the coast, storm duration; and from preconditioning due to rising sea level, such that the storm waves can overtop protective barriers that provided adequate defense when sea level was lower. Water added to the oceans from melting glacier, ice caps, and ice sheets is a significant cause of sea level rise. In particular, the Greenland Ice Sheet is projected to be a major contributor to sea level rise during the present century. Much of the recently observed contribution is a response to warming ocean temperatures around Greenland, which cause marine-terminating glaciers to melt and calve icebergs into the ocean. Models that are used to predict this anticipated sea level rise exhibit a broad spread in ocean temperatures around the Greenland Ice Sheet, for reasons that are not well understood. This project is designed to improve understanding of the physical processes responsible for this spread in projected ocean temperatures amongst models.The lead principal investigator for this project, through his ongoing work with local and state governments, will ensure that the results are relevant to and transferred to planners and policy-makers. His parent company will assist in a similar information transfer to the private sector. The project will also contribute to workforce development through support for the training of a graduate student in state-of-the-art interdisciplinary science and through support of three early-career scientists during their formative years. The detailed mechanistic understanding provided by this work will reveal: the physical processes underlying the spread in CMIP5 projections of near-Greenland ocean warming; the nature and location of the surface fluxes driving warming; and the linkages between warming at different depths and different locations around the ice sheet. It will also provide a physical basis for linkages between near-Greenland ocean warming and other related Arctic climate system processes (e.g. Northern Hemisphere sea ice and the Atlantic Meridional Overturning Circulation). These linkages are vital to understanding how climate-driven changes in Greenland?s mass balance are coupled to other processes such as the loss of sea ice and more general polar surface warming. A two-part strategy will be used to evaluate causal physical mechanisms underlying the spread in CMIP5 projections of ocean warming in an efficient and detailed manner. Statistical analysis of ocean temperature will cluster AOGCMs by their ocean warming patterns and their co-variability (across space and models) with surface fluxes and other climate processes. Numerical simulations, forced by surface fluxes from a representative subset of CMIP5 models, will then be used to develop detailed oceanic heat budgets. Targeted perturbation experiments will isolate the role of atmospheric and Greenland meltwater flux in the context of widely varying CMIP5 representations of the Arctic freshwater budget.

毁灭性的风暴潮是由风暴本身的特征的结合而产生的。例如风力，风暴的方向到海岸，风暴持续时间；从由于海平面上升而引起的前进，使风暴波可以超越保护屏障，在海平面较低时提供足够的防御能力。 融化冰川，冰盖和冰盖的水为海洋添加到海洋中，这是海平面上升的重要原因。 特别是，格陵兰冰盖预计是当今世纪中海平面上升的主要贡献者。 最近观察到的大部分贡献是对格陵兰周围海洋温度变暖的反应，这会导致海洋末端的冰川融化并使冰山融化到海洋中。 用于预测这种预期海平面上升的模型在格陵兰冰盖周围的海洋温度中显示出广泛的扩散，原因尚不清楚。该项目旨在提高对模型中预计海洋温度中这一传播的物理过程的理解。该项目的首席主要研究人员通过与地方和州政府的持续合作，将确保结果与计划者和政策制定者有关。 他的母公司将协助将类似的信息转移到私营部门。 该项目还将通过支持培训最先进的跨学科科学的研究生，并通过在成长年代的三名早期职业科学家的支持来为劳动力发展做出贡献。 这项工作提供的详细的机械理解将揭示：CMIP5近绿地海洋变暖中蔓延的物理过程；驱动变暖的表面通量的性质和位置；以及在不同深度和冰盖周围不同位置的变暖之间的联系。 它还将为近绿地海洋变暖与其他相关北极气候系统过程之间的联系提供物理基础（例如北半球海冰和大西洋子午线翻转循环）。 这些联系对于理解格陵兰质量的气候变化是至关重要的，质量平衡是如何与其他过程（例如损失海冰和更一般的极性表面变暖）结合的。 将使用两部分的策略来评估以有效且详细的方式在CMIP5投影中传播的因果物理机制。海洋温度的统计分析将通过其海洋变暖模式及其与表面通量和其他气候过程的共同变异（跨空间和模型）的可可变可定性（跨空间和模型）聚集。 数值模拟是由CMIP5模型代表性子集的表面通量强迫的，然后将用于制定详细的海洋热预算。 有针对性的扰动实验将在北极淡水预算的CMIP5代表变化的背景下隔离大气和格陵兰融化通量的作用。