Ozone zonal asymmetry and planetary wave characterization during Antarctic spring
A large zonal asymmetry of ozone has been observed over Antarctica\nduring winter-spring, when the ozone hole develops. It is caused by a\nplanetary wave-driven displacement of the polar vortex. The total ozone\ndata by OMI (Ozone Monitoring Instrument) and the ozone profiles by MLS\n(Microwave Limb Sounder) and GOMOS (Global Ozone Monitoring by\nOccultation of Stars) were analysed to characterize the ozone zonal\nasymmetry and the wave activity during Antarctic spring. Both total\nozone and profile data have shown a persistent zonal asymmetry over the\nlast years, which is usually observed from September to mid-December.\nThe largest amplitudes of planetary waves at 65A degrees S (the\nperturbations can achieve up to 50% of zonal mean values) is observed\nin October. The wave activity is dominated by the quasi-stationary wave\n1 component, while the wave 2 is mainly an eastward travelling wave.\nWave numbers 1 and 2 generally explain more than the 90% of the ozone\nlongitudinal variations. Both GOMOS and MLS ozone profile data show that\nozone zonal asymmetry covers the whole stratosphere and extends up to\nthe altitudes of 60-65 km. The wave amplitudes in ozone mixing ratio\ndecay with altitude, with maxima (up to 50%) below 30 km.\nThe characterization of the ozone zonal asymmetry has become important\nin the climate research. The inclusion of the polar zonal asymmetry in\nthe climate models is essential for an accurate estimation of the future\ntemperature trends. This information might also be important for\nretrieval algorithms that rely on ozone a priori information.