Shelf-Basin Exchange in the Chukchi Sea

观察到的北冰洋夏季海冰覆盖率持续下降的部分原因是海水携带的热量。这些热量通过直接的太阳加热和来自大西洋和白令海的热量输送进入北冰洋。来自大西洋的温暖海水被较冷的次表层海水隔离，与海冰直接接触。这个项目将开发一个模式，综合我们对北冰洋重要物理过程的理解，将模式输出与观测结果进行比较，利用模式增加对调节海冰热通量的过程的了解，并了解在这些过程中观察到的最新趋势。首席调查员建议，利用非常高分辨率的区域数值模式，结合近期和历史观测，研究导致楚科奇海内部水团转化、跨陆架断裂交换到盆地内部以及冰融化的过程。该模式是一个受天气气压场强迫、流经白令海峡的海冰/海冰耦合模式。负责质量、热量、淡水和示踪剂跨搁板交换的物理过程将被诊断。模型中的环流和通量将与现场系泊和水文资料进行比较。拟议研究的目的是更好地了解北冰洋太平洋部分跨陆架交换的过程，它们与内陆冰川融化的关系，以及它们可能如何在不断变化的北极气候中发生变化。区域模式的重点是诊断陆架-盆地交换的机制，并将它们与该区域的基本强迫机制(流经白令海峡和大气)联系起来。区域模型的效率允许进行大量计算，并允许检验与交换有关的假设。这种基于过程的方法允许对控制物理学有一个普遍的理解，对其他地区和强迫情景具有更广泛的影响。首席研究员在麻省理工学院-世界卫生组织物理海洋学联合项目中教授研究生水平的课程，在这个项目中开发的材料将被纳入他的课程。他还参与了GFD暑期班，并将在暑期班讲授从这项研究中获得的理解。在数学和物理方面很强的本科生也将被招募通过世界卫生组织暑期学生奖学金计划从事模型分析工作，这个项目是免费的。PI还建立了一个网站，向更广泛的受众总结和突出他的研究兴趣。

The observed ongoing decline of summer sea ice coverage in the Arctic Ocean results, in part, from heat carried by ocean waters. This heat enters the Arctic Ocean by direct solar heating and by the transport of heat with flows from the Atlantic Ocean and Bering Sea. The warm waters from the Atlantic Ocean are isolated from direct contact with the sea ice by subsurface colder waters. This project will develop a model that synthesizes our understanding of important physical processes in the Arctic Ocean, compare the model output to observations, use the model to increase understanding of the processes responsible for modulating heat flux to the sea ice, and understand the observed recent trends in those processesThe principal investigator proposes to study processes that lead to water mass transformation within the Chukchi Sea, exchange across the shelfbreak to the basin interior, and the melting of ice using a very high resolution regional numerical model in conjunction with recent and historical observations. The model is a realistically configured coupled ocean/sea ice model forced by synoptic atmospheric fields and flow through Bering Strait. Physical processes responsible for exchange of mass, heat, freshwater, and tracers across the shelfbreak will be diagnosed. The circulation and fluxes in the model will be compared with in-situ mooring and hydrographic data. The objectives of the proposed study are to better understand the processes responsible for cross shelf exchange in the Pacific sector of the Arctic Ocean, their relation to ice melt in the interior, and how they might change in a changing Arctic climate. The focus of the regional model is to diagnose the mechanisms responsible for shelf-basin exchange and relate them to the basic forcing mechanisms in this region (flow through Bering Strait and the atmosphere). The efficiency of the regional model allows for large numbers of calculations to be carried out, and for hypotheses relating to exchange to be tested. Such a process-based approach allows for a general understanding of the controlling physics with broader implications for other regions and forcing scenarios.The principal investigator teaches graduate level classes in the MIT-WHOI Joint Program in Physical Oceanography, and the material developed during this project will be incorporated into his classes. He has also been involved in the GFD summer school and will offer summer school lectures about the understanding gained from this study. Undergraduate students strong in mathematics and physics will also be recruited to work on the model analysis through the WHOI Summer Student Fellowship program at no cost to this project. The PI also maintains a web site that summarizes and highlights his research interests for a broader audience.