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

自本世纪初以来的观测表明，北极的自然环境和相关的生态系统正在发生显著的变化，为了预测未来的变化，我们需要能够量化北极气候变率和变化与海洋环流的联系程度，海冰的分布如何对气候模式预测的北极变暖放大作出反应，以及初级生产力如何、物种分布和相关的生态系统结构将随着北极状态的演变而改变。我们对这些过程驱动机制的理解取决于我们对北极系统的了解，以及我们以与观测相一致的方式模拟其随时间变化状态的能力。该项目将采用先进的方法综合海洋学观测，开发一种工具，建立对北极系统的基本认识。拟议的研究成果将包括更好地量化自世纪之交以来北极系统的变化，并提高对这些变化的动力原因的理解。由此得出的海洋和海冰性质分析领域很可能在未来的研究中得到广泛的应用。该项目将把从船舶、飞机和自主仪器获得的水文观测数据，从现场浮标、卫星和有人驾驶船只获得的海冰数据，以及边界层气象学结合在一个状态估计基础设施中，对21世纪大约第一个十年期间北冰洋的演变进行物理和动态描述。利用不断增长的观测数据库，该项目的两个主要目标是：利用附带的北极亚极环流状态估计，创建一个动态一致的、综合的所有可用的北极水文和海冰观测数据，从2002年到现在；以及利用合成产物对推动北极系统演变的物理机制进行的科学调查。该小组将量化四个关键的科学问题：上层海洋水文和环流的时间平均值、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；以及北极和亚极地环流之间的联系，重点关注热量和FW的交换和反馈。生成的产品将是北冰洋及其邻近海域和北大西洋亚极地的时间平均、平均季节周期和时变量，这些变量表征了耦合的物理海洋-海冰状态、热量、FW、动量和涡量预算，以及推断的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、政策制定者、行业和公众。与麻省理工学院博物馆合作，将开展一项实质性的外展活动，汇集各种多媒体项目，这些项目使用包括本项目在内的科学成果，以可视化北冰洋正在发生的重大变化。其目标是使对多媒体项目感兴趣的一般受众与实际的科学数据集接触，从而在两种观点之间建立切实的联系。计划展览和相关活动的目的是创造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.