Ozone feedback stabilizes the quasi-biennial oscillation against volcanic perturbations

Abstract

Possible interference by volcanic aerosols with downward propagating quasi-biennial oscillation (QBO) in the equatorial stratosphere has been studied by using a mechanistic model that incorporates the feedback of ozone through short wave absorption. The ascending motion driven by the radiative heating due to volcanic aerosols could be combined with the QBO-induced upward motion to block the descent of the easterly shear zone of the QBO when the ozone feedback is not taken into account. However, as the ozone concentration in the cold easterly shear zone is relatively low and the aerosol-driven vertical ozone advection makes its concentration still lower, the negative anomalies of solar heating due to perturbed ozone compensate for the aerosol-induced diabatic heating. Thus the interactions between dynamics and radiation intermediated by the ozone feedback play an important role in stabilizing the time evolution of the QBO against perturbations by volcanic aerosols.