Time Evolution of Baroclinic Wave Activity in Stormtracks and Its Relationship with Jetstream Structure

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In the Northern Hemisphere winter, most of the synoptic scale storm activity is observed in two widely-separated midlatitude stormtracks, along the east coasts of Asia and the United States. There is evidence that the variability in wave (or storm) activity and the position of the stormtrack are related to low frequency variability of the basic flow in which they are embedded. Further, it appears that the waves influence the evolution of the basic flow pattern. While much evidence has been gathered in an averaged sense, there is still a need to understand the time evolution of the interactions. The purpose of this research is to investigate the time evolution of synoptic scale waves and along the major stormtracks and to relate it to low-frequency changes in the basic flow, specifically the structure of the jetstream. The study employs a 30-year data set. This research has important implications for improving medium and long range weather forecasting. If time permits, the PIs will also examine the relationship between the low-level easterly jet over Africa and the so-called easterly or African waves.