Stratosphere-Troposphere Coupling Studies

在过去的几十年里，随着臭氧层变薄，温室气体浓度增加，平流层的组成和环流发生了变化。在未来几十年，预计臭氧层将在温室气体浓度持续增加的背景下恢复。这些平流层变化很重要，因为它们会影响对流层天气和气候，特别是在高纬度地区。然而，我们对平流层的作用缺乏了解，给气候预测带来了不确定性，特别是因为我们不了解气候模型需要什么来模拟平流层变化对地面气候的实际影响。各种模型结果将与观测一起用于改善对平流层-对流层耦合以及天气和气候如何受到平流层变化影响的理解。该项目的一个具体目标是了解气候模型中需要什么，以便对平流层变化的影响以及准两年振荡(QBO)对地面气候和天气的影响进行现实模拟。QBO相当规律，通常可以提前数月预测，因此与对流层的关系有可能改善长期天气和气候预报。这项工作将有助于我们了解平流层变化将如何影响对流层气候，并通过参与国际努力，促进对气候变化和大气成分变化的科学评估。具有更广泛影响的活动包括：教授关于气候变化的中学课程；支持和培训博士后；公开下载数据(例如，环状模式指数)；让本科生参与研究项目；组织国际会议；以及编写一篇关于平流层-对流层耦合的综述，将发表在《地球物理评论》上。该项目将对世界气候研究方案的平流层过程及其在气候中的作用(SPARC)项目作出贡献。

Over the past several decades, the composition and circulation of the stratosphere have changed, as the ozone layer has thinned and concentrations of greenhouse gases have increased. In the coming decades, the ozone layer is expected to recover against a background of continued increases in greenhouse gas concentrations. These stratospheric changes are important, because they can affect tropospheric weather and climate, especially at high latitudes. Our poor understanding, however, of the role of the stratosphere introduces uncertainty in climate projections, especially because we do not understand what is required of climate models to simulate realistic effects of stratospheric changes on surface climate.A wide variety of model results, together with observations, will be used to improve understanding of stratosphere-troposphere coupling and of how weather and climate are affected by stratospheric variability. A specific goal of this project is to gain an understanding of what is required in climate models to obtain realistic simulations of the effects of stratospheric changes, as well as effects of the quasi-biennial oscillation (QBO), on surface climate and weather. The QBO is fairly regular, and is generally predictable many months in advance, so relationships with the troposphere have the potential to improve long-range weather and climate forecasts. This work will contribute to our understanding of how stratospheric change will affect tropospheric climate, and through involvement in international efforts, contribute to scientific assessments of climate change and changes in atmospheric composition.Activities with broader impacts include: teaching middle school classes on climate change; supporting and training a postdoc; making data publicly available for download (e.g., annular mode indices); involving undergraduate students in the research project; organizing international conferences; and preparing a review of stratosphere-troposphere coupling, to be published in Reviews of Geophysics. This project will contribute to the World Climate Research Programme's Stratospheric Processes and their Role in Climate (SPARC) project.