Title: Global jet stream trends and impacts
Speaker: Tim Woollings (Oxford)
Abstract: Climate models have long predicted that the global jet streams will shift polewards under climate change. Here we will look at evidence that this signal is emerging in observations and consider some relevant mechanisms, including the role of the tropical Pacific warming pattern. A large set of hindcast experiments from the Met Office seasonal forecasting system will be used alongside more conventional methods to provide evidence for the shift. Subtropical regions are arguably most at risk from a poleward jet shift, so we look at the role of such dynamical trends in recent precipitation declines in these regions, and discuss the extent to which we can separate dynamic and thermodynamic mechanisms of change.