Collaborative Research: Understanding Arctic System Change Through Synthesis of Hydrographic and Sea Ice Observations from the early 21st Century

自本世纪之交以来进行的观测表明，北极的物理环境和相关生态系统正在发生显著变化，为了预测未来的变化，我们需要能够量化北极气候变异和变化与海洋环流的联系，海冰的分布如何对气候模型预测的北极变暖的放大作出反应，以及初级生产力，物种分布和相关的生态系统结构将随着北极状况的变化而变化。我们对这些过程的驱动机制的理解取决于我们对北极系统的了解以及我们以与观测一致的方式模拟其随时间演变的状态的能力。该项目将采用一种先进的方法综合海洋学观测结果，以开发一种工具，建立对北极系统的基线了解。拟议研究的成果将包括更好地量化北极系统自世纪以来的变化，并加深对这些变化的动力学原因的理解。这是可能的，由此产生的海洋和海冰特性的分析领域将被广泛使用的社区在未来的研究。该项目将把从船舶、飞机和自动仪器获得的水文观测数据、从现场浮标、卫星和载人船只获得的海冰数据以及边界层气象学纳入一个状态估计基础设施，以便对大约在21世纪头十年期间不断变化的北冰洋进行物理和动力描述。该项目利用不断扩大的观测数据库，其两个主要目标是：利用2002年至今期间基于伴随的北极次极地环流状况估计，对所有现有的北极水文和海冰观测数据进行动态一致和全面的综合;利用综合产品对推动北极系统演变的物理机制进行科学调查。该团队将量化四个关键科学问题：上层海洋水文和环流的时间平均，季节周期和年际变化;北冰洋热量和淡水（FW）含量的年际变化;海冰状态和海气通量的变化;北极和次极地环流之间的联系，重点是热量和FW交换和反馈。所产生的产品将是时间平均值，平均季节周期，并在北冰洋，其邻近海域和亚极地北大西洋的全套变量的随时间变化的数量，其特征耦合的物理海洋-海冰状态，热量，FW，动量和涡度预算，并推断海气通量和时间平均海洋湍流混合。这些产品将提供给研究人员和学生、决策者、工业界和公众。将与麻省理工学院博物馆合作开展大量外联活动，汇集各种多媒体项目，利用科学成果，包括本项目的成果，使北冰洋正在发生的重大变化形象化。其目标是让对多媒体项目感兴趣的普通观众参与实际的科学数据集，以在两个视角之间建立切实的联系。计划举办展览和相关活动，目的是制作可随时用于更广泛传播的材料。该项目将支持两名女性早期职业科学家。

Observations made since the turn of this century indicate that the Arctic physical environment and associated ecosystems are undergoing remarkable changes and to predict future changes we need to be able to quantify how much of Arctic climate variability and change is linked to the ocean circulation, how the distribution of sea ice responds to the amplified Arctic warming predicted by climate models, and how primary productivity, species distributions and associated ecosystem structures will change with the evolving Arctic state. Our understanding of the driving mechanisms for these processes depends on our knowledge of the Arctic system and our ability to simulate its time-evolving state in a way that is consistent with observations. This project will employ an advanced approach for synthesizing oceanographic observations to develop a tool that establishes a baseline understanding of the Arctic system. Outcomes of the proposed research will include better quantification of the Arctic system's changes since the turn of the century, and improved understanding of the dynamical causes for these changes. It is likely that the resulting analyzed fields of ocean and sea ice properties will be widely utilized by the community in future research. This project will bring together hydrographic observations obtained from ship, aircraft and autonomous instruments, sea ice data from in situ buoys, satellites and manned vessels, and boundary-layer meteorology within a state estimation infrastructure to develop a physical and dynamical description of the evolving Arctic Ocean during roughly the first decade of the 21st century. Taking advantage of a growing observational database, the project's two main objectives are: the creation of a dynamically-consistent and comprehensive synthesis of all available Arctic hydrographic and sea ice observations using the adjoint-based Arctic Sub-polar gyre sTate Estimate for the period 2002-present; and scientific investigations, using the synthesis products, of physical mechanisms driving the evolving Arctic system. The team will quantify four key science issues: the time-average, seasonal cycle, and interannual variability of the upper-ocean hydrography and circulation; the interannual changes in Arctic Ocean heat and freshwater (FW) content; changes in the sea ice state and air-sea fluxes; and connections between the Arctic and the Sub-polar gyre, focusing on heat and FW exchanges and feedback. Products generated will be the time-mean, mean seasonal cycle, and time-varying quantities in the Arctic Ocean, its neighboring seas and sub-polar North Atlantic of the full set of variables characterizing the coupled physical ocean-sea ice state, heat, FW, momentum and vorticity budgets, and inferred air-sea fluxes and time-mean oceanic turbulent mixing. These products will be made available to researchers and students, policy makers, industry, and the general public. A substantial outreach activity will be undertaken, in collaboration the MIT Museum, to assemble diverse multimedia projects that use scientific results, including those from this project, to visualize changes due to ongoing major shifts in the Arctic Ocean. The goal is to engage the general audience interested in the multimedia projects with actual scientific datasets to establish tangible links between the two perspectives. Exhibitions and accompanying events are planned with a goal of creating material that may be readily used for broader dissemination. The project will support two female early career scientists.