Collaborative Research: A Global Bridge From Eddy-Rich to Eddy-Less: Quantifying, Mapping, and Improving Treatment of Mesoscale Eddy Tracer Fluxes

以前的模型需要“英雄计算”来模拟十年的模型时间，现在类似的模型运行了几个世纪。然而，仍然需要中尺度涡旋参数化：不断增加的系统复杂性、模拟长度、集合大小以及在台式计算机上运行海洋模式需要在未来几十年内连续使用粗略模式。理想情况下，涡旋参数应直接对照观测值进行验证，但所需观测值的密度使此选项不切实际。针对更高分辨率计算的测试是一种有效的替代方案，但这些比较很少或不完全完成。该项目将以直接和彻底的方式在全球范围内提供这样的比较。将产生三个产品：1)在高分辨率模拟中对完整的涡流搅拌张量进行全局诊断，2)与现有的参数化预报的搅拌张量进行比较，以及3)？基于精细分辨率模式中的涡旋区域。大多数现存的涡旋参数可以完全用涡旋搅拌张量来表示。这一张量的诊断比目前最先进的研究有了很大的进步，只诊断了标量涡流扩散或其他有限的张量结构。与全张量全局一致是一项严格的测试，它将导致立即改进或完全拒绝参数化。除了用于比较的数据集之外，拥有用于参数化开发的测试用例也很有用。传统上，涡流参数化在容易出现伪影的理想化环境中进行了测试。这项研究的第三个产品将是一套可能由全球高分辨率模拟中的原型构建的6个挑战。挑战赛将提供足够的信息，作为独立的前进模式运行。全套挑战将被设计为在所有挑战中成功的参数化将预测在全球模型中可能的成功。在粗略海洋模式的中尺度涡旋的参数化方面已经取得了很大的进展，但下一步的精度需要在富涡的数据集和测试套件中更好地定义度量，以验证现有的和即将到来的参数化。这项研究将提供可获得的直接产品和适度的计算机资源，在现实的流通中诊断的全球性将防止常见的伪影。该项目将增加对全球尺度中尺度涡旋动力学和涡旋参数化基本假设的理解，改进或拒绝现有的涡旋参数化方案，并测试一种新的诊断方法。该项目将支持两名职业生涯早期的研究人员和一名研究生，公开提供大型模拟的可管理大小版本，导致海洋和气候模型的改进，导致POP模型的性能改进，并支持和鼓励研究机构和建模人员与更大社区的合作。

The previous models required a "hero calculation" to simulate a decade of model time, now similar models run for centuries. However, mesoscale eddy parameterizations are still needed: increasing system complexity, simulation length, ensemble size, and running ocean models on desktop computers require a continuous use of coarse models for decades to come. Ideally, eddy parameterizations should be validated directly against observations, but the density of observations required renders this option impracticable. Tests against higher resolution calculations are an effective alternative, but these comparisons are rarely or incompletely done. This project will provide such a comparison globally in a direct and thorough manner. Three products will emerge: 1) a global diagnosis of the complete eddy stirring tensor in a fine-resolution simulation, 2) a comparison to the stirring tensor predicted using extant parameterizations, and 3) a ?parameterization challenge suite? based on eddying regions in the fine-resolution model. Most extant eddy parameterizations may be written completely in terms of the eddy stirring tensor. Diagnosis of this tensor represents a significant advance over presently state-of-the-art studies diagnosing only a scalar eddy diffusivity or otherwise limited tensor structure. Agreement with the full tensor globally is a stringent test that will lead to immediate improvement or wholesale rejection of parameterizations. In addition to a dataset for comparison, it is useful to have test cases for parameterization development. Traditionally, eddy parameterizations have been tested in artifact-prone idealized settings. The third product of this study will be a suite of perhaps 6 challenges constructed from prototypes in the global high-resolution simulation. A challenge will provide enough information to be run as a stand-alone forward model. The full suite of challenges will be designed so that a successful parameterization in all challenges will predict likely success in a global model. Much progress has been made in parameterizing mesoscale eddies in coarse ocean models, but the next level of accuracy requires better defined metrics in eddy-rich datasets and test suites against which extant and forthcoming parameterizations can be validated. This study will provide direct products accessible with moderate computer resources, and the global nature of the diagnosis in a realistic circulation will prevent common artifacts. The project will increase understanding of mesoscale eddy dynamics on a global scale and the assumptions underlying eddy parameterizations, improve or reject extant eddy parameterization schemes, and test a novel diagnostic methodology. The project will support two early-career researchers and a graduate student, publicly provide manageably-sized versions of a huge simulation, lead to improvements in ocean and climate models, lead to performance improvement of the POP model, and support and encourage collaboration among research institutions and modelers with the larger community.