Measurements to parameterizations: mixing in the open and coastal oceans

海洋混合是地球系统的一个重要组成部分，它将热量向下驱动，将营养物质向上混合，并为沿海到全球范围的海洋环流提供能量。量化、表征和预测海洋混合是一项艰巨的任务，因为必须解决空间和时间尺度的扩展。我们的团队对海洋混合进行了创新的测量，并开发了简化的海洋物理模拟，阐明了混合机制。将观察和模拟结合在一组在国际上是罕见的。******我们建议关注四种混合过程。第一个是测量横向搅拌过程在东北太平洋使用我们的波动移动船舶剖面和船舶的电流剖面。随着数值模式开始解析中尺度涡旋，我们需要对亚中尺度过程进行新的参数化，以确保这些模式正确地混合了上层海洋中涡旋传播的热量和营养物质。北太平洋是测量这些过程的一个很好的实验室，因为温暖的加利福尼亚潜流与寒冷的阿拉斯加环流横向混合。我们的测量将有助于在贝德福德海洋研究所正在开发的模式中为这种混合的未来参数化设定基线。******第二个过程是在陡地形上混合。我们已经开发了一个参数化潮汐产生的湍流在孤立的测深。然而，在这项工作对大规模模拟有用之前，我们必须将其应用于更复杂的水深测量。这将涉及二维和三维的新模拟，并将成为令人兴奋的学生论文。******第三个过程是对Knight Inlet（一个沿海峡湾）的潮汐能预算进行数值限制。像奈特湾或夏威夷这样的孤立地形上的潮汐能量收支表明，表面潮汐损失的大部分能量以内部潮汐的形式辐射出去。没有人能拿出一份可靠的预算，表明这种能量最终会在哪里消散。我们建议对Knight Inlet进行高分辨率模拟，因为它很受限制，我希望我们可以在未来的现场项目中验证其机制。******最后，我建议继续研究生肯·休斯的工作，研究混合和水力流动在控制北冰洋淡水流经加拿大北极群岛并进入北大西洋中的作用。最近的大尺度模型高估了这些流的输送高达80%，表明这些模型中缺少物理。我们将对通过这些通道的流动进行高分辨率的嵌套模拟，包括冰的影响，并与大型建模器合作，以参数化由于未分解的水力流动而导致的流动的形式阻力和混合。******虽然这些问题中有许多是加拿大当地的问题，但它们都与更好地理解全球重要的混合过程有关。

Ocean mixing is a crucial component of the earth system, driving heat downwards, mixing nutrients upwards, and energizing ocean circulations from coastal to global scales. Quantifying, characterizing, and predicting ocean mixing is a daunting task given the spread of spatial and temporal scales that must be resolved. Our group makes innovative measurements of ocean mixing and develops simplified ocean-physics simulations that elucidate the mixing mechanisms. The combination of observations and simulation in one group is rare internationally.******We propose to focus on four mixing processes. The first is to measure lateral stirring processes in the North East Pacific using our undulating Moving Vessel Profile and a ship's current profiler. As numerical models start to resolve mesoscale eddies we need new parameterizations of submesoscale processes to make sure these models mix eddy-borne heat and nutrients properly in the upper ocean. The NE Pacific is a good laboratory to measure these processes, as the warm California Undercurrent mixes laterally with the cold Alaskan gyre. Our measurements will help set the baseline for future parameterization of this mixing in models being developed by Bedford Institute of Oceanography.******The second process is mixing at abrupt topography. We have developed a parameterization for tidally generated turbulence over isolated bathymetry. However, before this work is useful for large-scale simulations, we must extend its use to more complicated bathymetry. This will involve new simulations in both two and three dimensions, and will make exciting student theses.******The third process is to numerically confine a tidal energy budget in Knight Inlet, a coastal fjord. Tidal energy budgets over isolated topography like the sill in Knight Inlet or Hawaii indicate that much of the energy lost from the surface tide radiates away as internal tides. No one has closed a credible budget indicating where that energy eventually dissipates. We propose to do this for a high-resolution simulation of Knight Inlet simply because it is well-confined, and I hope that we can verify the mechanisms in future field programs.******Finally, I propose to carry on the work of graduate student Ken Hughes, examining the role of mixing and hydraulic flows in controlling the flow of fresh Arctic Ocean water through the Canadian Arctic Archipelago and into the North Atlantic. Recent large-scale models overestimate the transport of these flows by up to 80%, indicating missing physics in those models. We will carry out high-resolution nested simulations of the flow through these channels, including the effect of ice, and working with large-scale modellers to parameterize the form drag due and mixing on the flow due to underresolved hydraulic flows.******While many of these problems are local to Canada, they all have relevance to better understanding globally important mixing processes.