Seminar

Abstract

The jet-stream and storm tracks are fundamental aspects of the atmospheric circulation, being situated in the midlatitudes, and obtaining their energy from the equator-to-pole temperature gradient. The internal variability of the jet-stream is very large, manifesting itself on a range of timescales: e.g. daily, monthly, decadal. Furthermore, one of the most robust predictions of state-of-the-art climate models (CMIP5 ensemble) is that the jet-stream position and variability will change over the 21st Century as greenhouse gas concentrations continue to increase.

Here, we explore the role of jet-stream variability in driving variability in tropospheric transport and air quality and the implications of a changing jet over the next century. We will present results that the position and variability of the midlatitude jet can be used to understand present-day surface ozone variability, and that the jet stream can serve as a dynamical predictor of future ozone variability. Additional results will be presented on the potential role of the midlatitude storm track in driving the seasonality of carbon dioxide in the Arctic, further highlighting how variability of the midlatitude jet can lead to variability in tropospheric transport.

Finally, given that the majority of the CMIP5 models place the jet-stream too far equatorward compared to observations, (varying in position up to 7 degrees in latitude), model biases in the jet position could have significant implications for projections of air quality and transport in a warmer world.