Possible ozone influence on the quasi-biennial oscillation in the equatorial stratosphere

Abstract

Crossspectral analysis between the time series of zonal wind velocity in the equatorial stratosphere and the flux of solar UV radiation revealed high coherence between the variations of these two parameters on a quasibiennial scale (24-30 months) in the atmo� spheric layer 500-1 hPa (~6-48.5 km). A lag of the quasibiennial variations in wind velocity behind the quasibiennial variations in the solar radiation flux, the maximum (~ 24 months) of which is located at a level of 100 hPa (16.5 km), decreases with height, and in the stratopause region (~1 hPa), the wind velocity variations are approximately in phase with the varia� tions in the solar radiation flux. This points at the pos� sibility of the influence of quasibiennial variations in the shortwave solar radiation on the quasibiennial oscillation of the zonal wind in the neighborhood of the equatorial stratopause. It has been shown that the meridional gradient and the curvature degree of the meridional profile of ozone concentration in this layer undergo quasibiennial variations such that could be a cause of synchronization between the quasibiennial variations in the wind velocity and thermal variations according to the solar wind equation. 1. The quasibiennial oscillation (QBO) manifests itself most clearly in the change of the direction of the