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

破坏性风暴潮是风暴本身特征的综合结果；例如，风的强度、风暴接近海岸的方向、风暴持续时间；以及海平面上升造成的预适应，使风暴波可以超过在海平面较低时提供充分防御的防护屏障。冰川融化、冰盖和冰盖向海洋注入的水是海平面上升的重要原因。特别是，格陵兰冰盖预计将是本世纪海平面上升的主要原因。最近观察到的大部分贡献是对格陵兰岛周围海洋温度上升的反应，这导致海洋末端的冰川融化并将冰山崩解到海洋中。用于预测预期海平面上升的模型显示了格陵兰冰盖周围海洋温度的广泛分布，原因尚不清楚。该项目旨在提高对模型间海洋温度预测扩散的物理过程的了解。该项目的首席调查员通过他与地方和州政府的持续工作，将确保结果与规划者和政策制定者相关并传递给规划者和决策者。他的母公司将协助向私营部门传递类似的信息。该项目还将通过支持对一名研究生进行最先进的跨学科科学培训，以及通过支持三名处于成长期的早期科学家，来促进劳动力发展。这项工作提供的详细机制理解将揭示：在CMIP5中预测格陵兰附近海洋变暖的传播的物理过程；驱动变暖的地表通量的性质和位置；以及不同深度和冰盖周围不同位置的变暖之间的联系。它还将为近格陵兰岛海洋变暖与其他相关的北极气候系统过程(如北半球海冰和大西洋经向翻转环流)之间的联系提供物质基础。这些联系对于理解气候驱动的格陵兰-S物质平衡变化是如何与其他过程(如海冰消失和更广泛的极地表面变暖)相关联的至关重要的。将使用分两部分的战略，以有效和详细的方式评估海洋变暖的CMIP5预测传播背后的因果物理机制。对海洋温度的统计分析将根据海洋变暖模式以及它们与地表通量和其他气候过程的协变性(跨空间和模式)对AOGCM进行分类。然后，在CMIP5模式的一个代表性子集的表面通量的强制下进行数值模拟，以制定详细的海洋热量收支。有针对性的扰动实验将在北极淡水收支的CMIP5大不相同的背景下隔离大气和格陵兰融水通量的作用。

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.