Parameterizing Mesoscale Ocean Eddies Over Bottom Topography

中尺度海洋涡旋在驱动大尺度海洋环流（Hallberg and Gnanadesikan 2006）和确定全球海洋分层（Karsten et al. 2003）方面起着至关重要的作用。因此，它们可能会影响全球和局部气候预测以及海洋热量和碳储存能力（Munday等人，2014年）。因此，在气候模式中精确模拟中尺度海洋涡旋是未来气候预测的重要工具。然而，气候模式的分辨率很少足以对涡旋进行明确的模拟，因此，在气候模式中对涡旋进行了参数化，在气候模式中使用的主要参数化方案是Gent和McWilliams的方案（以下简称GM 90），在该方案中，涡旋引起的速度通过厚度扩散系数k（Gent和McWilliams，1990）被参数化为示踪物的附加平流。GM 90是一个非常成功的方案，已被大多数CMIP模型采用（Eyring et al. 2016），并导致粗分辨率海洋模型精度的提高（Danabasoglu et al. 1994）。GM 90方案的一个明显缺陷是它无法对海底地形的变化做出反应。改善海底地形的涡参数化问题将是本项目的重点。

Mesoscale ocean eddies play a crucial role in driving large scale ocean circulation (Hallberg and Gnanadesikan 2006) and determining the global ocean stratification (Karsten et al. 2003). Consequently, they mayaffect global and localized climate predictions as well as ocean heat and carbon storage capacity (Munday et al. 2014). Accurate simulation of mesoscale ocean eddies in climate models is therefore an importanttool for future climate projections. However, the resolution of climate models is rarely sufficient for eddies to be explicitly simulated and they have therefore been parameterized in climate models.The prevailing parameterization scheme used in climate models is that of Gent and McWilliams (hereafter referred to as GM90) in which the eddy-induced velocity is parameterized as an additional advection oftracers via the thickness diffusivity, k (Gent and McWilliams, 1990). GM90 is a hugely successful scheme, having been adopted into most of the CMIP models (Eyring et al. 2016) and leading to improvements inthe accuracy of coarse resolution ocean models (Danabasoglu et al. 1994). One obvious flaw in the GM90 scheme is its inability to respond to variations in ocean floor topography. The problem of improving eddyparameterization over bottom topography will be the focus of this project.