Abstract: A comprehensive climatology of Northern Hemisphere blocking is described based on a PV?? wave-breaking index at the latitude of the climatological storm track and using the 40-yr ECMWF Re-Analysis (ERA-40) dataset. The ...

Abstract: The morphology of regional blocking in the Northern Hemisphere is discussed using the 40-yr ECMWF Re-Analysis (ERA-40) dataset and a measure of blocking based on the reversal at storm-track latitudes of meridional ? contrasts ...

Abstract: Rossby wave breaking on the dynamical tropopause in the Southern Hemisphere (the ?2-PVU surface) is investigated using the ERA-40 dataset. The indication of wave breaking is based on reversal in the meridional gradient of ...