Effects of Ozone on Stratospheric Wave-Mean Flow Interaction: Implications for Stratosphere-Troposphere Communication

Stratosphere-troposphere communication is an integral part of the climate system. Up until the past decade or so, most attention has been focused on the effects of the more massive troposphere on the stratosphere. However, an ever-growing body of evidence continues to build showing that the stratosphere has a greater influence on the troposphere than previously thought. To faithfully represent this stratosphere to troposphere influence requires a faithful description of the interactions between dynamics, radiation, and chemistry in the stratosphere. Indeed, Nathan and Cordero (2007, J. Geophs. Res.) have recently shown, using a newly derived ozone-modified refractive index for vertically propagating planetary waves, that the interactions between dynamics, radiation and ozone have an important impact on both wave propagation and planetary wave drag. Here we extend Nathan and Cordero's linear study by constructing a mechanistic model of stratospheric wave-mean flow interaction that includes the effects of ozone heating; the ozone heating is due to photochemically accelerated cooling and ozone advection by the planetary wave field. Numerical simulations show that the planetary wave-induced ozone heating affects the period and intensity of the wave-mean interaction, which manifests in the frequency of sudden stratospheric warmings, downward wave reflection, and the residual circulation. These results are discussed in light of natural and human-caused changes in stratospheric ozone.