VERTICAL STRUCTURE OF THE EXTRATROPICAL QUASI-BIENNIAL OSCILLATION INOZONE, TEMPERATURE, AND WIND DERIVED FROM OZONESONDE DATA

An analysis of the extratropical ozone sounding data shows that ozone, temperature, and wind as well as tropopause height reveal interannual variability with timescales in the range 24-30 months. This quasi-bie nnial variability is noticed, as a rule, in a whole range of ozone sou nding heights (0-35 km) and connected with the equatorial quasi-bienni al oscillation (QBO). The QBOs in ozone and temperature are revealed d ifferently in the middle and lower stratosphere as well as in the trop osphere. In the middle stratosphere a downward phase progression of th e ozone QSO is noticed similar to that of the equatorial dynamical QBO s. The rate of the phase descent of the QBO depends on the geographica l region and varies from 0.5 km/month to 1 km/month. In the northern h emisphere the rate is greatest in the polar region but lowest in the s ubtropics. Local maxima are noticed in the vertical structures of the ozone QBOs. In the northern midlatitudes these maxima are centered at heights of about 12, 20, and 30 km. In the lower stratosphere the QBO in ozone is in phase with that in temperature. Mean amplitudes of the temperature QBO in the troposphere are close td those in the stratosph ere. The downward phase progression of the temperature QBO is noticed in the northern midlatitude stratosphere. There is an abrupt phase shi ft between the QBOs in ozone and temperature in the lower stratosphere and those in the middle troposphere. Over the North American stations the phase shift is that the temperature QBOs in the troposphere are i n opposite phase with those in the stratosphere. In zonal and meridion al winds the QBO are revealed in the northern midlatitudes. In contras t with the QBOs in ozone and temperature, the wind QBOs reveal the sma ll rate of the phase changing with height. There are no significant ph ase shifts between the wind QBO in the lower stratosphere and that in the troposphere. The maximum amplitudes of the wind QBO are noticed in the vicinity of the tropopause position and at heights of 25-30 km. A mplitudes of the QBO in zonal wind are close to those in meridional wi nd. The QBO of tropopause height exposed in the northern hemisphere ha s the greatest amplitude over Japan. The tropopause height QBO is in o pposite phase (in phase) with the QBOs in ozone and temperature in the lower stratosphere (troposphere). Vertical structures of the QBOs obt ained for ozone, temperature, and wind in the stratosphere as well as the corresponding QBO of tropopause height support a hypothesis that t he extratropical QBO is caused by quasi-biennial forcing of the mean d iabatic meridional circulation by planetary-scale waves with the resul ting modulation of vertical advection.