Collaborative Research: Upper ocean heat flux in the Eurasian Basin: Oceanic thermodynamic forcing contributing to Arctic ice loss

提供的资金用于加深对从欧亚盆地东部(300oE)的大西洋水(AW)向上输送热量的机制和大小的了解，以便能够对不同大范围气候变化情况下大西洋水的不同横向输入做出准确的预测。具体目标是：O1。评估和改进双扩散对流(DDC)引起的热通量和盐通量的参数化，包括DDC热通量对附加速度切变(例如，平均流、潮汐)的敏感性；O2。利用2007年和2009年所有现有的北极东部微结构、冰系留剖面仪(ITP)和电导率-温度-深度(CTD)数据绘制DDC参数的空间分布图；使用三维斜压、包括潮汐强迫的海/海-冰耦合模式估计速度切变的空间分布；评估湍流混合和DDC过程在形成EB上升通量方面的相对作用；O5。评估DDC和具有层结和切变的反馈对EB水文结构的影响(通过建模)；估计横向侵入热通量，评估它们在海洋内部通风中的作用。PIS建议对一套具有良好垂直分辨率的现有水文数据进行高级分析？微结构、CTD、ITP和MacLane系泊剖面仪？利用国际社会近十年来收集的独特的EB数据集。一个具有活跃海冰的高分辨率3D区域海洋模式将被用来量化平均流、涡旋和潮汐的上层海洋切变，并提供一个工具来研究模拟通量对DDC、切变诱导的湍流和DDC/切变耦合的参数化的敏感性。

Funds are provided to develop understanding of the mechanisms and magnitude of heat transport upward from the Atlantic Water (AW) in the eastern (30oE) Eurasian Basin (EB), to the point where accurate projections can be made for varying lateral input of AW under different scenarios of large-scale climate variability. Specific objectives are:O1. To evaluate and improve parameterizations of heat and salt fluxes due to double-diffusive convection (DDC) including the sensitivity of DDC heat fluxes to added velocity shear (e.g., mean flow, tides);O2. To map the spatial distribution of DDC parameters using all available eastern Arctic microstructure, Ice-Tethered Profiler (ITP) and Conductivity-Temperature-Depth (CTD) data for 2007 and 2009;O3. To estimate the spatial distribution of velocity shear using a 3D baroclinic, coupled ocean/sea-ice model including tide forcing;O4. To evaluate the relative roles of turbulent mixing and DDC processes in shaping EB upward fluxes;O5. To estimate impact of DDC and feedbacks with stratification and shear on the hydrographic structure of the EB (via modeling); andO6. To estimate the lateral intrusive heat fluxes, assessing their role in ventilating the ocean interior.The PIs propose advanced analyses of a suite of existing hydrographic data with fine vertical resolution ? microstructure, CTD, ITP and MacLane moored profilers ? taking advantage of the unique EB dataset collected over the recent decade by the international community. A high-resolution 3D regional ocean model with active sea ice will be used to quantify upper ocean shear from mean flow, eddies and tides, and provide a tool for investigating sensitivity of modeled fluxes to parameterizations of DDC, shear-induced turbulence, and DDC/shear coupling.