A New Framework for the Investigation of Stratosphere-Troposphere Coupling

Abstract:

A new framework for exploring the dynamics and transport associated with stratosphere-troposphere coupling, based on dominant potential vorticity structures, is examined in a simplified dynamical model. Specifically, the framework is used here to consider the interaction between a resonant, topographically excited barotropic sudden warming and developing baroclinic lifecycles of differing characteristics. The influence of the sudden warming on details of the baroclinic development, including growth rates and low-latitude excursions of polar air, is examined under different vortex conditions including those in which the vortex splits more or less completely in the vertical, or exhibits a relatively rapid partial recovery. Extensions of the work to more comprehensive dynamical models and to include the effects of other dynamical features are considered briefly.