MESoscale Ocean eddies and Climate Predictions (MESO-CLIP)

中尺度海洋漩涡(MOE)是在世界海洋中普遍存在的水的漩涡(通常直径为几百公里)。MOES在海洋上相当于大气层中的天气系统。类似于天气系统，MoE不能提前很长时间预测。在海洋的计算机模型中，只有当模型能够分辨的空间尺度足够小时，MoES才能发展。通常，一个模式需要能够分辨大约30公里的尺度(在中纬度)才能开始产生MOE。然后，海洋模型就被认为是允许涡流的。要很好地表示MOE，分辨率的空间尺度至少需要10公里。具有这种分辨率的海洋模型通常被称为涡旋分辨。直到最近，用于气候预测的气候模式的网格分辨率太粗(100公里或更远)，无法模拟MOE。这种情况现在正在改变，正在开发的最新一代气候模型使用了允许涡流(很快就会涡流解析)的海洋成分。高分辨率模式中MOE发生的时间和地点取决于初始条件(模式模拟开始时的温度、盐度和速度)。即使初始条件的微小变化最终也会导致不同的MoE场。这类似于天气模式，通常在几天内采用不同的模式，即初始条件在预报开始时受到干扰。教育部如何反馈气候的可变性和可预测性在很大程度上仍是未知的。然而，最近的一些研究表明，海洋和大气变化可能在年际到年代际时间尺度上产生影响。目前正在开发的前沿气候模式使用允许涡流的(例如英国的HadGEM3-H)和涡旋分解的海洋(例如美国的CM2.6)，因此需要更好地了解MOE如何影响基于此类模型的预报。MESO-CLIP的主要目标将是确定初始条件(温度、盐度、速度)必须如何在允许/分解涡流的海洋模式中受到扰动，以评估预报中的不确定性。我们将使用一系列数值模式：(I)以1/4度(赤道25公里)和1/12度(赤道9公里)的水平网格分辨率运行的非耦合全球海洋模式，(Ii)英国气象局目前正在开发的最新海洋-大气耦合模式(HadGEM3-H)，它使用1/4度海洋分量，以及(Iii)涡旋分辨率(1/20度)分辨率的理想化海洋-大气耦合模式。有了这套模型，我们将能够研究海洋中MoE的存在如何影响海洋和大气的可预测性和可变性，以及耦合过程(海洋和大气之间的相互作用)可能有多重要。因此，MESO-CLIP将提供关于目前和未来将用于气候预测的高分辨率耦合模式中的预测不确定性的宝贵知识。

Mesoscale ocean eddies (MOEs) are swirls of water (typically a few hundred km in diameter) that are ubiquitous in the World Ocean. MOEs are the oceanic equivalent of weather systems in the atmosphere. In analogy to weather systems MOEs cannot be predicted a long time in advance. In computer models of the ocean MOEs can only develop if the spatial scale that the model can resolve is small enough. Typically a model needs to be able to resolve scales of about 30km (at mid-latitudes) to start generating MOEs. An ocean model is then said to be eddy-permitting. For a good representation of MOEs the resolved spatial scales need to be at least 10 km. Ocean models with that resolution are often referred to as eddy-resolving. Until recently, the grid resolution in climate models used for climate prediction was too coarse (100 km and more) for MOEs to be simulated. This is now changing and the latest generation of climate models under development use ocean components that are eddy-permitting (and soon eddy-resolving). When and where MOEs occur in high resolution models depends on initial conditions (the temperature, salinity and velocities at the beginning of the model simulation). Even small changes in initial conditions will eventually lead to different MOE fields. This is analogous to weather patterns typically adopting different patterns in a matter of days when the initial conditions are perturbed at the beginning of a forecast. How MOEs feed back on climate variability and predictability is still largely unknown. However, some recent studies suggest that MOEs could affect ocean and atmosphere variability on interannual to decadal timescales. Cutting edge climate models currently under development use eddy-permitting (e.g. HadGEM3-H in the UK) and eddy-resolving (e.g. CM2.6 in the US) oceans and therefore there is a need to get a better understanding of how MOEs affect forecasts based on such models. The main goal of MESO-CLIP will be to determine how initial conditions (temperatures, salinities, velocities) have to be perturbed in eddy-permitting/resolving ocean models to assess the uncertainty in forecasts. We will use a hierarchy of numerical models: (i) an uncoupled global ocean model run at horizontal grid resolutions of 1/4degree (25km at Equator) and 1/12degree (9 km at Equator), (ii) the latest coupled ocean-atmosphere model currently under development at the UK MetOffice (HadGEM3-H) which uses a 1/4degree ocean component, and (iii) an eddy-resolving (1/20degree) resolution idealised coupled ocean-atmosphere model. With this set of models we will be able to address how the presence of MOEs in the ocean affect the predictability and variability of ocean and atmosphere and how important coupled processes (interactions between the ocean and the atmosphere) are likely to be. MESO-CLIP will therefore provide valuable knowledge about forecast uncertainties in present and future high resolution coupled models that will be used for climate predictions.