Collaborative Research: Long-term Observations in the Switchyard Region of the Arctic Ocean as Part of the Arctic Observing Network (AON)

学术价值：该奖项支持在加拿大埃尔斯米尔岛北部和格陵兰岛北部进行的三年海洋观测，那里的水通过弗拉姆海峡和纳尔斯海峡向南流出北冰洋。“开关站”观测工作是美国国家科学基金会北极观测网络(AON)的一部分，该网络支持长期的、科学驱动的观测，使研究能够了解北极环境系统的快速变化。怡安是更广泛的北极环境变化研究(SEARCH)的一个组成部分。“调度场”观测的关键要素是：(1)在Alert和北极之间使用CTD-O/玫瑰花环系统的机载部分，以确定水文性质和一套示踪剂/碳系统变量，目的是通过测量氟氯化碳和氚/氦-3来解决相对年龄结构，并通过测量上层水柱中的氧-18和钡来确定淡水成分；(2)对林肯海进行机载水文/示踪剂/碳调查，目的是捕捉区域淡水路线和边界流与通过“调度场”区域的跨极漂移之间的前沿的变化；以及(3)完成横跨纳雷斯海峡以西陆架斜坡的8个系泊阵列，目的是捕捉进入纳雷斯海峡和弗拉姆海峡的加拿大盆地周围的水团的结构和运输。该奖项的成功完成将把“交换站”的观测记录延长到10年，这将使研究人员能够提高对以下方面的理解：(1)水团特征及其对层结、昼夜热通量以及热和盐输送的影响；(2)淡水清单(包括以海冰形式储存的淡水)；(3)向北大西洋释放淡水；(4)上层水层的热量收支及其与海冰覆盖的相互作用；(5)海冰环流和厚度分布；以及(6)未来的环流模式。更广泛的影响：北极正在向一个更温暖的世界过渡，在“转换场”获得的数据将提供北极环境系统如何应对人为强迫的早期迹象。通过项目网站和北极合作数据与信息服务中心(CADIS)，更广泛的科学界可以免费、公开地获得这些数据。与美国国家科学基金会的其他Aon项目和国际项目的合作有助于协调和整合Aon和Search由科学驱动的海洋和海冰观测部分。该项目通过本科生和研究生参与并积极参与在西雅图太平洋科学中心举行的极地科学周末，促进教育和外联，以激励新一代科学家和工程师。

Intellectual merit: This award supports a further three years of ocean observations in the 'Switchyard', the area north of Ellesmere Island, Canada, and Greenland, where water flows south out of the Arctic Ocean via Fram and Nares straits. The 'Switchyard' observing effort is part of the NSF Arctic Observing Network (AON), which supports long-term, science-driven observing that enables research into understanding rapid environmental system change in the Arctic. AON is a component of the broader Study of Environmental Arctic Change (SEARCH). The key elements of the 'Switchyard' observations are: (1) an aircraft-based section using a CTD-O/rosette system between Alert and the North Pole of hydrographic properties and a set of tracers/carbon system variables aimed at resolving the relative age structure via CFC and tritium/helium-3 measurements and freshwater components via oxygen-18 and barium measurements in the upper water column; (2) an aircraft-based hydrography/tracer/carbon survey of the Lincoln Sea aimed at capturing changes in the regional freshwater routing and the front between the boundary current and the transpolar drift passing through the 'Switchyard' region; and (3) completion of an 8-mooring array across the shelf slope just west of Nares Strait aimed at capturing the structure and transport of the water masses coming around the Canada Basin on their way to Nares and Fram straits. Successful completion of the award will extend the 'Switchyard' observational record to 10 years, which will allow researchers to improve the understanding of the following: (1) water mass characteristics and their effect on stratification, diapycnal heat fluxes, and transport of heat and salt; (2) freshwater inventories (including that stored in form of sea ice); (3) freshwater release to the North Atlantic Ocean; (4) heat budget of the upper water layers and its interplay with the sea ice cover; (5) sea ice circulation and thickness distribution; and (6) future circulation patterns. Broader Impacts: The Arctic is undergoing a transition into a warmer world, and the data obtained in the 'Switchyard' will provide early indications of how the Arctic environmental system is responding to anthropogenic forcing. The data are freely and openly available to the broader scientific community via project Web sites and at CADIS (Cooperative Arctic Data and Information Service), the AON data repository. Collaboration with other NSF AON projects and international projects contributes to coordination and integration of a science-driven ocean and sea ice observing component of AON and SEARCH. The project contributes to education and outreach to inspire a new generation of scientist and engineers via undergraduate and graduate student participation and active involvement in the Polar Science Weekend at the Pacific Science Center, Seattle.