9312655, PI-Montgomery, "Baroclinic Wave Packet Dynamics in Low Level Confluent/Diffluent Flow as a Mechanism for Tropical Cyclogenesis": In earlier research, the principal investigator investigated the interactions of upper level potential vorticity disturbances and low level disturbances as a possible mechanism for tropical cyclones initiation. While this mechanism appears to be important in the subtropics, it is not clear whether it applies to the deep tropics as well. Under this award, Dr. Montgomery will simulate and diagnose the cyclogenetic potential of baroclinic wave packets in barotropic confluent/diffluent flow (basically corresponding to the flow in the boundaries between subtropical highs) in both dry and moist neutral atmospheres, using a three dimensional semi geostrophic model. The study would attempt to mimic the passage of a tropical easterly wave into a region of confluence or diffluence. In addition, he will other possible lifting mechanisms such as the beta effect and isolated vortices in shear flow.
