Stratosphere-troposphere Interactions

将研究环模在气候变率动力学中的作用，特别是(I)平流层结构和环流的变化可以影响对流层纬向流从而影响地面气候的动力机制，(Ii)对流层和平流层涡旋反馈过程在这种相互作用的动力学中所起的作用，以及(Iii)涨落耗散定理对理解纬向流对外部扰动的响应的适用性。虽然这项研究是部分理论分析，但大部分研究将包括一套简化的平流层-对流层环流模式的实验。未来的实验将包括地面地形，以确保平流层Rossby波活动的现实水平，以及模式气候中现实的非地带性程度。这些研究将进一步了解大气环状模式，并确定可能提供充分耦合以导致平流层对对流层产生重大影响的过程。这项研究的更广泛的影响是气候模拟的实践：如果正确地模拟平流层是模拟地表气候的重要先决条件，那么对气候模型也有重要的影响。此外，这项工作将对理解外加扰动的动态影响，特别是温室气体增加和臭氧消耗对气候的影响具有重要意义。

The role of annular modes in the dynamics of climate variability will be investigated, focusing especially on (i) the dynamical mechanisms by which changes in the structure and circulation of the stratosphere can affect the tropospheric zonal flow, and thence surface climate, (ii) the role that tropospheric and stratospheric eddy feedback processes play in the dynamics of this interaction, and (iii) the applicability of the fluctuation-dissipation theorem to the understanding of the response of the zonal flow to external perturbations. While this investigation is part theoretical analysis, the bulk of the research will comprise suites of experiments in a simplified stratosphere-troposphere general circulation model. Future experiments will include surface topography, in order to ensure a realistic level of stratospheric Rossby wave activity, as well as a realistic degree of non-zonality in the model climate. These studies will further understanding of atmospheric annular modes, and identify the processes that may provide sufficient coupling to lead to significant stratospheric influences on the troposphere. Broader impacts of this research are for the practice of climate modeling: if modeling the stratosphere correctly is an important prerequisite to modeling surface climate, there are important implications for climate models. Further, this work will have implications for the understanding of the dynamical impact of imposed perturbations, especially of increasing greenhouse gases and ozone depletion on climate.