InMotion: Influx of Momentum into the Arctic Ocean - Changes Associated with Sea Ice Reduction

PI建议基于再分析资料研究地面风，权衡大尺度大气环流和局地大气边界层不稳定对其变化的影响。此外，包括海冰动量平衡中的所有变量的预算将使用最先进的冰洋模型来计算。这使得能够估计地面风和海洋应力、冰厚度和冰集中对最近观测到的北冰洋海冰运动加速的单独影响。将考虑到由于冰层面积缩小而引起的海洋表面气海和冰海应力的可能变化。为此目的，模型结果将用冰块密度和冰块漂移的卫星数据进行验证。这些发现最终将被合并成一幅综合图片，记录和解释过去30年来流入北冰洋的动量通量的变化。拟议的研究还将旨在预测动量通量的未来演变。最近，有人假设，耦合的全球环流模型无法正确预测北极海冰特征的趋势，可能是因为它们缺乏涉及海冰强度的动态反馈过程。这项拟议的工作将旨在反驳这一假设，或者理解普通海冰模型在描述这种动态反馈方面可能存在的缺陷。从大气到北冰洋的动量通量增加预计将导致更多的垂直混合，可能会将更温暖的海水从深处带到海面附近，在那里它们可能有助于加速海冰的丧失。这项研究将提高我们理解和预测这种动量通量未来变化的能力。因此，它有助于我们理解和管理北极的资源开采、航运和生态系统变化，所有这些都依赖于海冰的演变。

The PI proposes to study the surface wind based on reanalysis data, weighing theinfluence of the large-scale atmospheric circulation and local atmospheric boundary layer destabilization on its changes. Further, a budget including all variables in the sea ice momentum balance will be calculated using a state-of-the-art ice?ocean model. This enables the estimation of the individual effect of surface wind and ocean stresses, ice thickness, and ice concentration on the recently observed acceleration of the Arctic sea ice motion. Likely changes in the partitioning of air?sea and ice?sea stresses at the ocean surface due to the shrinkage of the ice area will be taken into account. For this purpose the model results will be validated with satellite data of ice concentration and ice drift. These findings will finally be combined into an integrative picture documenting and explaining the changes of the momentum flux into the Arctic Ocean during the past three decades. The proposed research will also aim to predict the future evolution of the momentum flux. Recently, it has been hypothesized that coupled global circulation models are incapable of correctly projecting trends in Arctic sea ice characteristics, perhaps because they lack dynamic feedback processes involving sea ice strength. The proposed work will aim to either disprove the hypothesis or understand the possible deficiencies of common sea ice models to represent such dynamic feedbacks.Increased momentum flux from the atmosphere to the Arctic Ocean can be expected to result in more vertical mixing, possibly bringing warmer waters from depth to near the sea surface where they may contribute to acceleration of the loss of sea ice. This study will enhance our ability to understand and predict the future changes in this momentum flux. Consequently, it contributes to our understanding and management of resource extraction, shipping, and ecosystem change in the Arctic, all of which depend on the evolution of the sea ice cover.