CAREER: Ready to Resolve: Subgridscale Physics for Mesoscale Ocean Large Eddy Simulations

气候模型是了解我们的世界以及我们在其中扮演的角色的关键工具。从季节到世纪，这些模式的大部分记忆都是海洋成分，而大部分地下海洋能量都保存在中尺度涡旋中。这些涡流输送能量、动量、盐度和其他示踪物，从而影响气候。然而，直到现在，计算能力才使得以足够的分辨率运行气候模式成为可能，以允许或解决更大的涡流，避免许多不确定的参数在未解决的（亚网格）尺度上近似涡流的影响。这种被PI称为“中尺度海洋大涡模拟（mole）”的新模式将在未来几十年与我们在一起，但很少有专家接受过理解和改进它们的培训。即使在摩尔中，也有一些现象无法解决。因此，仍然需要一种形式的子网格建模，但是旧的方法在没有解决涡流时设计的，在解决了一些涡流和没有解决一些涡流时将不能很好地执行。原型模型表明，即使鼹鼠对子网格模型的选择也有些敏感，因此需要注意。该项目在Fox-Kemper和menmenenlis（2008）的成熟子网格模型的基础上进行扩展，将建立和培训一个新的团队来实施和评估适合于提高现代模拟分辨率的子网格模型。摩尔子网格模型将结合过去为粗分辨率开发的涡动子网格模型的优点（水质量保存、系统提取势能、平流和扩散输运以及中性物理）和大涡模拟子网格模型的主要优点；自调节幅度，尺度感知，鲁棒的数值稳定性，收敛与增加的分辨率，并避免重复计数。智力优势：PI已经在理想化的环境中评估了mole子网格模型，并提出了在现实模型中实现的可行途径。有待进一步开发的子网格模型似乎结合了上述所有特征。这个CAREER研究将承担这两个任务，使用一个由本科生、研究生和博士后研究人员组成的团队：1)将使用新的诊断方法来评估和区分子网格模型的行为。这些诊断也为全球能量预算和潜在涡量提供了线索。2)主要交付成果是这种新型子网格模型，这是当前和未来几代海洋环流建模所急需的，将在本合同期间对其进行评估、增强和实施。更广泛的影响为了建立和培养这支未来的科学家队伍，布朗大学将开发一套新的课程来教育来自地质（包括地球物理）、物理、工程和应用数学系的学生。一名早期职业教师、一名研究生、一名博士后，以及一组STEM和非STEM本科研究人员将获得终身资助。这一努力将重新向布朗大学介绍自20世纪50年代以来缺失的物理海洋学。与“拯救海湾”联合开展的面向公众和K-12学生的外展活动将对全球和罗德岛的气候模型进行教育。Save The Bay的教育工作者将接受培训，并获得由PI和小组与一群非stem的布朗罗德岛设计学院本科生合作开发的教材。下一代气候模式的基本原理将得到评估和改进。

Climate models are a key tool in understanding our world and our role in it. Much of the memory of these models, from seasons to centuries, is the oceanic component, and the majority of the subsurface ocean energy is held in mesoscale eddies. These eddies transport energy, momentum, salinity, and other tracers, and thereby affect the climate. Yet, it is only now that computational capabilities have made it possible to run climate models at sufficient resolution to permit or resolve larger eddies, avoiding many uncertain parameters approximating the influence of eddies at unresolved (subgrid) scales. This new class of models called by the PI "Mesoscale Ocean Large Eddy Simulations (MOLES)" will be with us for decades to come, yet few experts are trained to understand and improve them. Even in MOLES, some phenomena are unresolved. Thus, a form of subgrid modeling is still required, but the old approaches designed when no eddies were resolved will not perform well when some eddies are resolved and some are not. Prototype models show even MOLES are somewhat sensitive to choice of subgrid models, so care is required. This project, expanding on the proven subgrid model of Fox-Kemper and Menemenlis (2008), will build and train a new team to implement and evaluate subgrid models appropriate for the improving resolution of modern simulations. The subgrid models for MOLES will combine the advantages of past eddy subgrid models developed for coarse resolution use (water mass preservation, systematic extraction of potential energy, advective and diffusive transport, and neutral physics) with the key advantages of Large Eddy Simulation subgrid models; self-adjusting magnitude, scale-awareness, robust numerical stability, convergence with increasing resolution, and avoidance of double-counting.Intellectual Merit:The PI is already evaluating MOLES subgrid models in idealized settings, and suggests a viable pathway to implementation in realistic models. The subgrid model to be further developed seems to combine all features mentioned above. This CAREER research will take on these two tasks, using a team of undergraduate, graduate, and postdoctoral researchers: 1) New diagnostic approaches will be used to evaluate and differentiate the subgrid models' behavior. These diagnoses offer clues for global budgets of energy and potential vorticity as well. 2) The primary deliverable is this new class of subgrid models, greatly needed for the present and future generations of ocean circulation modeling, which will be evaluated, enhanced, and implemented during the course of this award.Broader ImpactsTo build and train this team of future scientists, a new suite of courses will be developed to educate students from Brown University's departments of geology (including geophysics), physics, engineering, and applied mathematics. One early-career faculty member, one graduate student, one postdoc, and a group of STEM and non-STEM undergraduate researchers will be supported though the lifetime of the award. This effort will reintroduce physical oceanography to Brown, missing since the 1950s. Outreach activities to the public and K-12 audiences in conjunction with Save the Bay will educate about climate modeling globally and in Rhode Island. Save The Bay educators will be trained and supplied with teaching materials developed by the PI and group, in collaboration with a group of non-STEM Brown & Rhode Island School of Design undergraduates. The fundamentals of the next generation of climate models will be evaluated and improved.