Non-stationarity of teleconnections in the climate system

在我读博士期间。我将研究遥相关及其在气候系统中的非平稳性。厄尔尼诺-南方涛动（ENSO）、印度洋偶极子（IOD）或北大西洋涛动（NAO）等不同气候模式彼此之间以及与其他过程之间的联系是活跃研究的大片领域（例如Rodriguez-Fonseca et al., 2016）。这些遥相关非常重要，因为气候模态之间的相互作用可以直接改变大区域的局部气候（例如欧洲的NAO变化）。此外，正如O'Reilly（2018）所表明的那样，热带和外热带之间的遥相关的存在会对我们预测温带气候的能力产生重大影响。O'Reilly等人（2019）已经表明，这些遥相关在过去发生了变化，在未来变暖的世界中也很可能再次发生变化。遥相关的变化和非平稳性也受到大气内部动力学的微小变化的高度影响，这些遥相关在过去发生变化的原因仍然存在很大的不确定性。因此，研究过去的这些变化，以了解远程连接在未来将如何变化，是非常重要的。作为第一个测试案例，将调查2019/2020年北欧极端温暖且可预测的冬季。反常冬季是由一个正的NAO驱动的。这个正的NAO可能有一些不寻常的远端连接模式活跃。因此，确定今年冬季的远程连接模式是理解为什么远程连接每年都不同的有用的第一步。

6During my PhD. I will be researching teleconnections and their non-stationarity in our climate system. The connections of different climate modes like the El Nino Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), or the North Atlantic Oscillation (NAO) to each other and to other processes are large areas of active research (e.g. Rodriguez-Fonseca et al., 2016). These teleconnections are of high importance as the interaction between climate modes can directly change the local climate of large regions (e.g. Europe for changes in the NAO). In addition the existence of teleconnections between tropics and extra tropics can have large impacts on our ability to forecast the extratropical climate as O'Reilly (2018) has shown. O'Reilly et al. (2019) have shown that these teleconnection changed in the past and will also very likely change in the future in a warming world again. The changes and non-stationarities of teleconnections are also highly influenced by small changes in internal atmospheric dynamics and there is still large uncertainties why these teleconnections changed in the past. Therefore it is of high importance to investigate these changes in the past to understand how teleconnections will change in the future. As a first test case, the extremely warm and well predictable winter in northern Europe of 2019/2020 will be investigated. The anomalous winter was driven by a positive NAO. This positive NAO likely had some unusual teleconnection patterns active. Identifying the teleconnection pattern of this winter is therefore a useful first step in understanding why teleconnections can differ from year to year.