Forced planetary waves generally extend throughout the troposphere and stratosphere and thus provide an important link between these two regions of the atmosphere. Because these planetary waves originate from mechanical and thermal forcing in the troposphere, planetary wave energy propagates upward into the stratosphere where momentum deposition via wave damping drives the zonal-mean stratospheric circulation. At the heart of this troposphere-stratosphere paradigm, wherein the troposphere forces the stratosphere, is the momentum deposition associated with the wave damping.

Here we present striking evidence showing that the interactions between ozone and the planetary waves not only affects the wave damping rate, but the interactions also produce changes in planetary wave structure and planetary wave fluxes that radiate downward into the troposphere.

Using analytical (WKB) and one-dimensional numerical modeling approaches, we show that there is a sensitive and intimate connection among the zonal-mean background flow, ozone field, and forced planetary wave field in the stratosphere, a connection that in some cases leads to significant changes in the tropospheric wave fluxes. We find that this stratosphere-troposphere connection, which hinges on the interactions between the wave and ozone fields, is dramatically strengthened in the presence of pseudo-critical levels, i.e., at those levels where the Doppler shifted frequency and potential vorticity gradient vanish. Such conditions are most often met during Northern Hemisphere spring and summer. We also discuss these results in light of changes in ozone arising from natural (e.g., 11-year solar cycle) and anthropogenic (e.g., chlorofluorocarbons) perturbations.