Collaborative Research: Energetically consistent, resolution aware, parameterization of meso-scale eddies in the ocean

GSTDTAP

项目编号	1536450
	Collaborative Research: Energetically consistent, resolution aware, parameterization of meso-scale eddies in the ocean
	Malte Jansen
主持机构	University of Chicago
项目开始年	2015
	2015-10-01
项目结束日期	2018-09-30
资助机构	US-NSF
项目类别	Standard Grant
项目经费	329821(USD)
国家	美国
语种	英语
英文摘要	The aim of this project is to develop a framework to parameterize eddy effects, which can be applied at both high and low model resolutions. While modeling groups put significant effort into increasing the spatial resolution of ocean climate models, longer-term global climate simulations are only starting to enter the "eddy-permitting" regime. Many idealized studies, as well as paleoclimate simulations, will continue to rely on models with even coarser resolutions for the foreseeable future. Adequate parameterizations representing sub-grid eddy effects at both "non-eddying" and "eddy-permitting" resolutions are thus crucial for our ability to produce adequate ocean climate simulations. Moreover, idealized modeling studies, performed in this project, will provide valuable insight about properties of mesoscale eddies and the turbulent energy cycle. This work further provides valuable training for an undergraduate intern, a graduate student and a postdoctoral researcher. They will be exposed to the theory of ocean turbulence, numerical model development and simulation, as well as analysis of big data sets, including both numerical model output and observational data. Finally, the project supports an early career PI, who is (re-)establishing physical oceanography research and education at The University of Chicago. To achieve a broadly applicable parameterization, this study will make use of an explicit budget for the sub-grid eddy kinetic energy, which combines ideas of Eden and Greatbatch (2008) and Jansen and Held (2014). This allows for a closure of sub-grid eddy effects that is consistent with the current understanding of the turbulent eddy energy cycle, while being simple and general enough to be readily implemented in a range of ocean climate models without adding significant computational cost. The sub-grid scales exchange energy with the resolved flow via parameterizations of baroclinic instability, as well as the turbulent cascade of kinetic energy and enstrophy. As discussed in Jansen and Held (2014), an adequate representation of the turbulent energy and enstrophy cascade requires the inclusion of energy "backscatter" from the subgrid-scales to the resolved flow, which so far has never been included in a realistic ocean model. This research is organized along three main thrusts: (1) Develop an EKE-budget-based eddy parameterization for non-eddying models, where baroclinic instability remains entirely unresolved. (2) Develop an EKE-budget-based eddy parameterization for "eddy-permitting" resolutions, where reasonable eddy-like disturbances can be simulated explicitly, but the resolution remains insufficient to fully resolve mesoscale eddies. (3) Combine the two limit cases into a generalized framework, which is applicable over a wide range of resolutions. The last step is crucial in light of the fact that models of a given resolution may be "eddy-permitting" in some parts of the ocean, while they are "non-eddying" in other parts of the ocean (Hallberg, 2013). The EKE-budget based approach naturally offers itself to the formulation of a parameterization that can adequately transition between these two regimes. The project goal will be achieved using a hierarchy of models, ranging from idealized process studies, to realistic global ocean models. This hierarchy will allow the team to develop a parameterization that is based in a fundamental understanding of the relevant physical processes, while also being applicable in complex state-of-the-art climate models. Success will be gauged by comparing the idealized numerical simulations to much higher resolution reference simulations, and ultimately by showing the global ocean models' improved ability to reproduce ocean observations.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68890
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Malte Jansen.Collaborative Research: Energetically consistent, resolution aware, parameterization of meso-scale eddies in the ocean.2015.