The Features of Ozone Quasi-Biennial Oscillation in Tropical Stratosphere and Its Numerical Simulation

The interannual variation of the vertical distribution of ozone in the tropical stratosphere and itsquasi-biennial oscillation (QBO) is analyzed using HALOE data. The results are compared with the windQBO. A numerical experiment is carried out to study the effects of wind QBO on the distribution, and varia-tion of ozone in the stratosphere by using the NCAR interactive chemical, dynamical, and radiativetwo-dimensional model (SOCRATES). Data analysis shows that the location of the maximum ozone mix-ing ratio in the stratosphere changes in the meridional and vertical directions, and assumes a quasi-biennialperiod. The meridional and vertical motion of the maximum mixing ratio leads to a QBO of column ozoneand its hemispheric asymmetry. The QBO of the location of the maximum is closely connected with the zon-al wind QBO. The data analysis also shows that in the tropical region, the phase of the QBO for ozone den-sity changes many times with height. Numerical simulation shows that the meridional circulation induced bythe wind QBO includes three pairs of cells in the stratosphere, which have hemispheric symmetry. Thetransport of ozone by the induced meridional circulation in various latitudes and heights is the main dynam-ic cause for the ozone QBO. Cells of the induced circulation in the middle stratosphere (25-35 km) play animportant role in producing the ozone QBO.