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

破坏性风暴潮是由风暴本身的特征组合而成的;例如风力强度、风暴接近海岸的方向、风暴持续时间;以及由于海平面上升而产生的预处理，使得风暴波可以越过在海平面较低时提供足够防御的保护屏障。 冰川、冰帽和冰盖融化后流入海洋的水是海平面上升的一个重要原因。 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升高的反应，这导致海洋终止冰川融化并将冰山分解到海洋中。 用于预测这种预期海平面上升的模型显示，格陵兰冰盖周围的海洋温度分布广泛，原因尚不清楚。该项目旨在提高对造成预测海洋温度在模型之间传播的物理过程的理解，该项目的首席研究员将通过他与地方和州政府的持续工作，确保结果与规划者和决策者相关并传递给他们。 他的母公司将协助向私营部门提供类似的信息。 该项目还将通过支持培训一名最先进的跨学科科学研究生，并通过支持三名职业生涯初期的科学家在他们的成长期，促进劳动力发展。 这项工作提供的详细的机械理解将揭示：在近格陵兰海洋变暖的CMIP 5预测的传播背后的物理过程;驱动变暖的表面通量的性质和位置;以及冰盖周围不同深度和不同位置的变暖之间的联系。 它还将为近格陵兰海洋变暖与其他相关的北极气候系统过程（例如北方半球海冰和大西洋经向翻转环流）之间的联系提供物理基础。 这些联系对于了解格陵兰岛气候驱动的变化是如何发生的至关重要？的质量平衡与其他过程相关联，例如海冰的损失和更普遍的极地表面变暖。 将采用一个由两部分组成的战略，以有效和详细的方式评估CMIP 5海洋变暖预测传播的因果物理机制。海洋温度的统计分析将根据海洋变暖模式及其与地表通量和其他气候过程的协变（跨空间和模式）对AOGCM进行聚类。 数值模拟，迫使表面通量从CMIP 5模式的一个代表性的子集，然后将用于制定详细的海洋热收支。 有针对性的扰动实验将隔离大气和格陵兰融水通量的作用，在广泛变化的CMIP 5代表北极淡水预算的背景下。

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.