ABSTRACT

"Much of the weather and climate variability experienced in Europe is associated with the North Atlantic eddy-driven jet stream. Here we develop some simple diagnostics to describe changes in the jet stream, and apply these to data from the ERA-40 reanalysis and from the suite of IPCC AR4 models. We use these to address questions such as: are there distinct preferred positions of the jet stream, and do the IPCC models really agree on a poleward shift of the jet stream in response to greenhouse gas forcing?"