Abstract
The Quasi-Biennial Oscillation (QBO) in the equatorial stratosphere affects the extratropical cyclonic vortex in the stratosphere by disposing it to act in either of two regimes: weak and warm in the east years of the QBO versus cold and intense in the west years. This influence of the QBO is, however, thwarted at the peaks of the 11-year sunspot cycle: at low solar activity the extratropical vortex reacts as expected, but at high solar activity the QBO signal is reversed. The high interannual variability in the arctic stratosphere is responsible for the lack of ozone depletion on the large scale observed in Antarctica.
