9510008 Chang The development and evolution of cyclones and anticyclones control, to a large extent, the weather in the mid-latitudes. These weather systems occur in preferred regions termed the storm tracks. It is important to understand the processes that can lead to the formation of these systems and their evolution. Recent observational and modelling studies have revealed that cyclones and anticyclones occur predominantly within localized wave packets. Preliminary studies suggest that the structure, evolution, and development of these systems within localized wave packets can be quite different from those suggested by traditional theories of baroclinic instability. Dr. Chang intends to explore in depth the evolution of these systems within the localized wave packets by diagnosing observational analyses from the European Centre for Medium Range Prediction and the National Center for Environmental Prediction and by conducting numerical experiments with a primitive equation model with simplified model physics. The results of this research will have important implications for medium range weather prediction (on the order of one to two weeks). *** ??
