In this review, we highlight the complementary relationship between simple and comprehensive models in addressing key scientific questions to describe Earth's atmospheric circulation. The systematic representation of models in steps, or hierarchies, connects our understanding from idealized systems to comprehensive models and ultimately the observed atmosphere. We define three interconnected principles that can be used to characterize the model hierarchies of the atmosphere. We explore the rich diversity within the governing equations in the dynamical hierarchy, the ability to isolate and understand atmospheric processes in the process hierarchy, and the importance of the physical domain and resolution in the hierarchy of scale. We center our discussion on the large-scale circulation of the atmosphere and its interaction with clouds and convection, focusing on areas where simple models have had a significant impact. Our confidence in climate model projections of the future is based on our efforts to ground the climate predictions in fundamental physical understanding. This understanding is, in part, possible due to the hierarchies of idealized models that afford the simplicity required for understanding complex systems. Plain Language Summary Model hierarchies are fundamental to our understanding of the large-scale circulation of Earth's atmosphere. They have played a critical role in forming and testing our ability to simulate and predict the natural variability of the atmosphere, such as the variations of the extratropical jet streams, and for exploring how the climate will respond to external forcing, such as increased carbon dioxide. In this review we discuss simple models that form the basis of our understanding of the atmosphere and how they connect to the comprehensive models used for climate prediction through the model hierarchies. We describe three principles that help organize the model hierarchies and discuss benchmark models that have been influential in understanding the large-scale circulation in the midlatitudes, middle atmosphere, and tropics.

中文翻译：

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理解大气环流的模型层次结构

在这篇综述中，我们强调了简单模型和综合模型在解决描述地球大气环流的关键科学问题方面的互补关系。模型在步骤或层次结构中的系统表示将我们的理解从理想化系统连接到综合模型，最终连接到观察到的大气。我们定义了三个相互关联的原则，可用于表征大气的模型层次结构。我们探索动态层次结构中控制方程的丰富多样性，在过程层次结构中隔离和理解大气过程的能力，以及尺度层次结构中物理域和分辨率的重要性。我们集中讨论大气的大规模环流及其与云和对流的相互作用，重点关注简单模型产生重大影响的领域。我们对未来气候模型预测的信心基于我们努力将气候预测建立在基本的物理理解基础上。这种理解在一定程度上是可能的，因为理想化模型的层次结构提供了理解复杂系统所需的简单性。简单语言总结 模型层次结构是我们理解地球大气大规模环流的基础。它们在形成和测试我们模拟和预测大气自然变化的能力方面发挥了关键作用，例如温带急流的变化，以及探索气候将如何应对外部强迫，例如二氧化碳增加。在这篇综述中，我们讨论了构成我们对大气理解基础的简单模型，以及它们如何通过模型层次结构与用于气候预测的综合模型联系起来。我们描述了有助于组织模型层次结构的三个原则，并讨论了对理解中纬度、中层大气和热带地区的大尺度环流有影响的基准模型。