Tropospheric Influences on Stratospheric Low-frequency Variability

该项目将有助于改进对未来气候变化的预测。这将使社会能够更好地为未来气候的自然变化和人为变化做好准备。该项目还将支持两名研究生的培训，这项研究的结果将纳入研究生水平的教学。最后，该项目将为地方、国家和国际气候变化外联活动提供支持。平流层极涡及其强度的变化在这种影响中起着关键作用。极地涡旋是一种西风系统，在极夜期间在北极平流层上发展。极涡的变化与平流层突然变暖（SSW）有关，但也可能有其他非SSW相关的原因。这一项目将有助于对平流层和对流层之间的动力耦合、所涉机制以及如何用模型模拟这一耦合有新的更好的认识。该项目还将有助于更好地了解气候模型中存在的缺陷及其对未来全球气候预测的影响。潜在地，这将提高进行年代际预测的能力，并可能对年代际趋势的确定和归因产生影响。它还可能有助于更准确地了解SSW发生率的未来变化，对臭氧的恢复做出更现实的预测，并提高气候变化预测的确定性。

This project will contribute to improved predictions of future variations of climate. This will allow society to prepare better for natural variations and anthropogenic changes of future climate. The project will also support the training of two graduate students, and the results from this research will be incorporated into graduate level teaching. Finally, this project will provide support for local, national, and international outreach activities on climate changeIt is now well established that conditions in the stratosphere influence weather and climate in the troposphere. The stratospheric polar vortex and variations in its strength play a key role for this influence. The polar vortex is a westerly wind system that develops during polar night over the Arctic stratosphere. Polar vortex variations are related to stratospheric sudden warmings (SSW), but there may be other non-SSW related causes as well. This project will contribute to new and improved insight into the dynamical coupling between stratosphere and troposphere, the mechanisms involved in it, and how to simulate it with models. The project will also contribute to improved understanding of deficencies present in climate models and the impact this has on future predictions of the global climate. Potentially, this will improve the ability to make decadal predictions, and it may have implications for the determination and attribution of decadal trends. It may also help to obtain a more precise picture of future changes in the occurrence rates of SSWs, make more realistic predictions of the recovery of ozone, and increase the certainty of climate change projections.