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，并为从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性的测量，并开发了简化的海洋物理模拟，阐明了混合机制。在一组中将观测和模拟结合在一起在国际上是罕见的。 我们建议集中在四个混合过程。第一个是测量横向搅拌过程在东北太平洋使用我们的起伏移动船舶剖面和船舶的电流剖面。随着数值模式开始解决中尺度涡旋，我们需要新的亚中尺度过程参数化，以确保这些模式在上层海洋中适当地混合涡旋传播的热量和营养物质。东北太平洋是一个很好的实验室来测量这些过程，因为温暖的加州暗流与寒冷的阿拉斯加环流横向混合。我们的测量将有助于为贝德福德海洋研究所正在开发的模型中的这种混合的未来参数化设定基线。 第二个过程是突变地形下的混合。我们已经开发了一个参数化潮汐产生的湍流孤立水深。然而，在这项工作对大规模模拟有用之前，我们必须将其应用扩展到更复杂的水深测量。这将涉及二维和三维的新模拟，并将使令人兴奋的学生论文。 第三个过程是数值限制在奈特湾，沿海峡湾的潮汐能预算。孤立地形上的潮汐能量收支，如奈特湾或夏威夷的岩床，表明大部分从表面潮汐中损失的能量作为内部潮汐辐射出去。没有人关闭一个可信的预算，表明能源最终消散在哪里。我们建议这样做的一个高分辨率的模拟骑士入口，只是因为它是很好的限制，我希望我们可以验证的机制，在未来的实地计划。 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通过加拿大北极群岛流入北大西洋中的作用。最近的大规模模型高估了这些流动的传输高达80%，这表明这些模型中缺少物理学。我们将对通过这些通道的流动进行高分辨率嵌套模拟，包括冰的影响，并与大型建模人员合作，以参数化由于欠分辨水力流动而引起的形式阻力和流动混合。 虽然这些问题中有许多是加拿大本地的，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.