Eddies, mixing and recent climate change

为了评估人类活动对气候系统的未来影响，我们需要运行气候预测模型。这些模型在很大程度上依赖于无法明确解决的过程，要么是因为计算机能力根本不可用，要么是因为模型太复杂，无法判断它们的可靠性。云的表示就是一个例子。几乎不可能想象在一个模型中明确地表示每一种云的物理性质，但众所周知，云在地球的辐射平衡中起着重要作用。这里我们关注的是海洋中尚未解决的过程的表现；特别是空间尺度从公里到几十公里的随时间变化的波动（“涡流”）。目前，我们在气候模型中表现涡旋的能力相当有限，但我们开始意识到涡旋在热量、淡水、碳和其他示踪物的预算中所起的基本作用，这些都是气候变化问题的核心问题。这项研究的目的是在我们过去在这个领域的工作的基础上，提高气候模型代表涡旋影响的能力。我们还讨论了最近的气候变化问题，试图揭示热带海洋和高层大气（如平流层）在大气中温室气体浓度增加的背景下所起的作用。这些活动结合起来应该会提高我们预测未来气候的能力，以及气候变化对加拿大人可能产生的影响。

To assess the future impact of man's activities on the climate system, we need to run climate prediction models. These models depend heavily on processes that cannot be resolved explicitly, either because the computer power is simply not available, or because the models would be too complex, making it impossible to judge their reliability. An example is the representation of clouds. It is almost impossible to imagine representing the physics of each cloud explicitly in a model, yet clouds are known to play a fundamental role in the Earth's radiation balance. Here we are concerned with the representation of unresolved processes in the ocean; in particular time dependent fluctuations ("eddies") with spatial scales from kilometres to tens of kilometres. Our ability to represent eddies in climate models is currently quite limited, yet we are beginning to realise the fundamental role played by eddies in the budgets of heat, freshwater, carbon and other tracers, issues central to the climate change problem. The proposed research is aimed at improving the ability of climate models to represent the effect of eddies, building on our past work in this field. We also address the issue of recent climate change in an attempt to unravel the role played by the tropical oceans and the upper atmosphere (e.g. the stratosphere) within the context of the increasing concentration of greenhouse gases in the atmosphere. These activities combined should lead to improvements in our ability to predict future climate, and the likely impact of climate change as it affects Canadians.