A shifting jet stream in a changing climate. Exploring the response of the polar jet stream in the Northern Hemisphere to various climate futures.

预计到21世纪，地球气候系统将经历重大变化，但这些变化预计不会以统一的方式发生。虽然当前一代气候模型的结果表明，预计北极地表温度在21世纪将比地球其他地区变暖得更快，但热带地区的哈德利环流预计将扩大，推动亚热带干旱区和风暴路径进一步向极地移动（Serreze等人，2009年，Hu等人，2018年）。这些类型的气候变化将极大地影响目前存在于北半球的热力学关系，改变那里天气系统的定位和特征。尽管如此，气候模式与观测之间普遍缺乏对控制天气状况变化的当前动力的一致性，部分原因是模拟高层大气的粒度（在上一代气候模式中），以及对于可以使用哪些代理来研究这一现象缺乏共识（CMIP5， Cohen等，2020）。本博士学位的主要目的是利用最新的耦合模式比对项目（CMIP6）的输出，探索喷气流（一种代用物）在各种未来气候情景的最先进气候模式中的响应。利用CMIP6模拟，该项目将寻找紧急和观测约束，以评估整个气候模式集合中未来急流行为的准确性和约束预测。

Earth's climate system is projected to experience significant changes into the 21st Century, but these changes have not expected to happen in a uniform way. While outputs from the current generation of climate models suggest surface temperatures in the Arctic are projected to warm faster than other parts of the planet into the 21st century, the Hadley circulation in the Tropics is expected to expand pushing both the sub-tropical dry zones and storm tracks further polewards (Serreze et al., 2009, Hu et al., 2018). These types of climatic shifts would considerably influence the current thermodynamic relationships that exist in the Northern Hemisphere, altering both the positioning and characteristics of weather systems there. Despite this, there is a general lack of agreement between climate models and observations on the current dynamics controlling changes in weather regimes, in part owing to granularity of the simulated upper atmosphere (in previous generation of climate models) and a lack of consensus over which proxy can be used study this phenomena (CMIP5, Cohen et al., 2020). The main aim of this PhD is to explore the response of the jet-streams, one such proxy, in state-of-the-art climate models across various future climate scenarios - making use of outputs from the latest Coupled Model Intercomparison Project (CMIP6). Using CMIP6 simulations, this project will search for emergent and observational constraints to evaluate the accuracy of, and constrain projections for, future jet-stream behaviour across the climate model ensemble.