Collaborative Research:Interaction of eddies with mixed layers

合作研究：涡流与混合层的相互作用

• 批准号: 0336808
• 负责人: Samar Khatiwala
• 金额: --
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0336808&HistoricalAwards=false
• 关键词: Collaborative; Research; Interaction; eddies; mixed

Parameterizations for the interaction of mesoscale eddies with turbulent mixing in the upper ocean will be derived and tested in climate models. Mesoscale parameterizations used in ocean general circulation models typically represent only the adiabatic release of available potential energy by eddies, as suggested by Gent and McWilliams. In the upper ocean, eddy fluxes develop a diabatic component because density is maintained vertically homogeneous by strong mixing while geostrophic motions are constrained to be horizontal near the boundary. Furthermore mesoscale strain interacts and modifies turbulent mixing at small scales. The dynamics of these diabatic surface eddy fluxes and their interactions with small-scale turbulence are not fully understood, and are not currently parameterized in the surface mixed layers of ocean models. Instead, tapering schemes are used to turn of the adiabatic eddy flux schemes at the surface. Coupled climate models are very sensitive to the choice of this tapering scheme. Here a new approach to eddy parameterizations, based on the Transformed Eulerian Mean is proposed. The new approach provides a unified framework for the treatment of eddy fluxes in the adiabatic interior and in the diabatic surface boundary layer.The project involves 1) analysis of observational data sets with key information on eddy transport in the upper ocean, 2) high resolution process models that explicitly resolve the full range of motions in the mixed layer, and 3) the derivation of new parameterization schemes based on a compromise between numerical efficiency and the theoretical information learned from observations and simulations. The main focus of the Team will be to implement and test the new parameterization schemes in the coupled climate models currently used in the modeling centers at GFDL, NCAR, and GSFC. This research is aimed at improving state of the art models of the atmosphere and ocean for study of the climate of the Earth and how it might change in the future. Thus it is of great societal impact. The project will also contribute to the education of a number of post-doctoral and graduate students bridging between observations, theory, and modeling.

在气候模型中，将得出和测试中海中尺度涡流与湍流混合的相互作用的参数化。如Gent和McWilliams所建议的那样，海洋通用循环模型中使用的中尺度参数化通常仅代表涡流的绝热释放。在上海上，涡流会形成绝热成分，因为密度通过强烈混合而垂直保持均匀，而地晶运动则在边界附近被限制为水平。此外，中尺度菌株在小尺度上相互作用并修饰湍流混合。这些绝热表面涡流及其与小规模湍流的相互作用的动力学尚未完全了解，目前尚未在海洋模型的表面混合层中进行参数化。取而代之的是，逐渐变细的方案用于转向表面的绝热涡流方案。耦合气候模型对此锥形方案的选择非常敏感。在这里，提出了一种基于转化的欧拉平均值的涡流参数化方法。新方法提供了一个统一的框架，用于治疗充满热的内部和绝热表面边界层中的涡流通量。项目涉及1）分析观察数据集的分析，其中包含有关上海中涡流运输的关键信息，2）高分辨率过程，2）高分辨率的过程模型，这些模型明确地分解了基于混合范围的范围和3）范围的运动范围，以及3）范围的范围，以及3），以及3）范围内的范围，3）范围内的范围范围。从观察和模拟中学到的理论信息。团队的主要重点是在GFDL，NCAR和GSFC的建模中心中使用的耦合气候模型中实现和测试新的参数化方案。这项研究旨在改善大气和海洋最先进的模型，以研究地球气候及其未来的变化。因此，它具有巨大的社会影响。该项目还将有助于对观测，理论和建模之间桥接的许多博士后和研究生的教育。