Measurements to parameterizations: mixing in the open and coastal oceans

参数化测量：公海和沿海海洋的混合

• 批准号: RGPIN-2017-04050
• 负责人: Klymak, Jody
• 金额: $ 1.97万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=655741
• 关键词: Measurements; parameterizations; mixing; open; coastal

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.

海洋混合是地球系统的关键组成部分，向下驱动热量，将养分向上融合，并从沿海到全球尺度的海洋循环充满活力。鉴于必须解决的空间和时间尺度的传播，量化，表征和预测海洋混合是一项艰巨的任务。我们的小组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，以阐明混合机制。一组观测和模拟在国际上很少见。******我们建议专注于四个混合过程。首先是使用我们起伏的移动船只和船舶的当前参考器测量东北太平洋的横向搅拌过程。随着数值模型开始解决中尺度的涡流，我们需要对集合过程的新参数化，以确保这些模型在上海上正确混合涡流热和营养。 NE Pacific是一个很好的实验室，可以测量这些过程，因为温暖的加利福尼亚暗流将其侧面与冷阿拉斯加Gyre横向混合。我们的测量结果将有助于为贝德福德海洋学研究所开发的模型中这种混合的未来参数化树立基线。******第二个过程是在突然的地形上进行混合。我们已经开发了用于在孤立的测深的潮汐产生的湍流的参数化。但是，在这项工作对于大规模模拟很有用之前，我们必须将其使用扩展到更复杂的测深。这将涉及两个和三个维度的新模拟，并将成为令人兴奋的学生论点。潮汐能量预算在孤立的地形上（例如骑士入口或夏威夷的窗台）表明，从表面潮汐中损失的大部分能量随着内部潮汐而散发出来。没有人关闭可靠的预算，这表明该能源最终消散了。我们建议这样做以进行骑士入口的高分辨率模拟，仅仅是因为它是有限的，我希望我们可以验证未来的现场计划中的机制。最近的大型模型高估了这些流量的运输多达80％，表明这些模型中的物理缺失。我们将对流过这些通道的流动进行高分辨率的嵌套模拟，包括冰的效果，并与大型模块厂一起工作，以参数化由于解决不足的液压流而引起的流量并混合流程。