Vertical spatial modulation of forced planetary waves in an atmosphere with stratospheric ozone heating: implications for stratosphere -troposphere coupling

Forced planetary waves extend throughout the troposphere and stratosphere and thus provide an important link between these two regions of the atmosphere. Although it is well established that vertically propagating planetary waves generated in the troposphere play a major role in driving the zonal-mean stratospheric circulation, an ever-growing body of evidence shows that the stratosphere may play a more important role in influencing the tropospheric circulation than previously thought. Here we examine the role of stratospheric ozone heating due to wave-ozone feedbacks in the vertical spatial modulation of tropospherically generated planetary waves. Using coupled equations for quasigeostrophic potential vorticity and ozone volume mixing ratio, a WKB analysis yields an analytical expression that shows how coupled wave-ozone interactions in the stratosphere can affect the reflecting surface associated topographically forced planetary waves. The analytical results have been confirmed numerically using climatological distributions of wind, temperature and ozone for each season. The numerical results show that depending on the height of the stratospheric reflecting surface, which is a strong function of season, the wave-ozone feedbacks can alter the planetary wave fluxes in the troposphere by as much as 5-10%. These results are discussed in light of stratospheric ozone perturbations arising from solar variability.