Collaborative Research: Mid-Latitude Modes of Climate Variability

0221066/0220700盖尔/杜瓦建议在十年和更长的时间尺度上研究耦合的中纬度气候变率。主要的假设是，这种变异性的一个关键组成部分来自内在的海洋来源。这一假设将使用海洋-大气耦合系统的数值模型进行分析，重点是海洋的风力驱动的可变性，而不是温盐环流的可变性。中等复杂性模型非常适合测试这一假设。该模型由海洋和大气两部分组成，每一部分都捕捉到了相应流体的湍流性质。我们建议的新特征是将这两个模型耦合起来，并分析由此产生的耦合湍流的性质。要同时在两种流体中实现湍流，需要使用各自的简化模型。更动态的完整模型在实现同样的目标时面临的一个基本问题是计算机能力不足。因此，将小尺度海洋变率的参数化为对海洋一般环流和气候的反馈，对于理解和预测耦合的气候变率是一个关键问题。将采取初步步骤，制定这些参数，并在该模型中进行测试。耦合环流模式还面临着耦合行为的现象学目前尚不清楚的问题，从而使模式结果的分析和解释变得复杂。这项工作将通过为耦合系统行为提供一个概念性的范例来帮助解决这个问题。这一建议的学术价值在于分析了与年代际时间尺度上的气候耦合问题相关的可行假说。这项工作的更广泛的影响在于在这一领域的两个主要机构(加州大学洛杉矶分校和南加州大学)之间发展科学伙伴关系，通过出版物、研讨会和在国家和国际会议上的发言来广泛传播我们的工作成果，并解决气候预测中的一个至关重要的社会问题。

0221066/0220700 Ghil/DewarIt is proposed to study coupled mid-latitude climate variability on decadal and longer time scales. The main hypothesis is that a critical component of this variability arises from intrinsic ocean sources. This hypothesis will be analyzed using a numerical model of the coupled ocean-atmosphere system, focusing on the oceans' wind-driven variability, rather than on that of the thermohaline circulation. An intermediate complexity model is ideally suited to test this hypothesis. The model consists of an oceanic and an atmospheric component, each of which captures the turbulent nature of the corresponding fluid. The new feature of our proposal is in coupling these two models, and analyzing the nature of the coupled turbulence that results. To achieve turbulence simultaneously in the two fluids requires working with reduced models of each. One fundamental problem faced by more dynamically complete models in achieving this same goal is insufficient computer power. Parameterization of small-scale oceanic variability as a feedback on the ocean's general circulation and on climate thus stands as a critical problem for understanding and predicting coupled climate variability. Initial steps will be taken towards formulating such parameterizations and testing them within this model. Coupled general circulation models also face the problem that the phenomenology of coupled behavior is not currently known, thus complicating the analysis and interpretation of model results. This work will contribute to a solution of this problem by providing a conceptual paradigm for coupled system behavior. The intellectual merit of this proposal is to analyze a viable hypothesis relevant to the coupled climate problem on inter-decadal timescales. The broader impacts of the work lie in developing scientific partnerships between two leading institutions (UCLA and FSU) in this field, broadly disseminating the results of our work by means of publications, seminars and presentations at national and international meetings, and addressing a problem of crucial societal importance in climate prediction.