[1] Reanalysis data are used to study the effects of the Quasi-Biennial Oscillation (QBO) and the El Niño–Southern Oscillation (ENSO) on the stratosphere. During the boreal winter in the Arctic, Warm ENSO (WENSO) months are found to be significantly warmer and Cold ENSO (CENSO) months significantly colder than climatology. The QBO is also found to have a large effect on the Arctic stratosphere ...

The QBO (quasi-biennial oscillation) is a quasi-periodic oscillation of the equatorial zonal wind between easterlies and westerlies in the tropical stratosphere with a mean period of 28 to 29 months. In this paper, the sensitivity of the impact of Mt. Pinatubo eruption in the tropics and extratropics to different QBO phases is in-5 vestigated. Mt. Pinatubo erupted in June 1991 during the easter...

Experiments with the Whole Atmosphere Community Climate Model (WACCM) are used to understand the influence of the stratospheric tropical Quasi-Biennial Oscillation(QBO) in the troposphere. The zonally symmetric circulation in thermal wind balance with the QBO affects high frequency eddies throughout the extratropical troposphere. The influence of the QBO is strongest and most robust in the Nort...

The interannual variability of the stratospheric polar vortex during winter in both hemispheres is observed to correlate strongly with the phase of the quasi-biennial oscillation (QBO) in tropical stratospheric winds. It follows that the lack of a spontaneously generated QBO in most atmospheric general circulation models (AGCMs) adversely affects the nature of polar variability in such models. ...

[1] The influence of the quasi-biennial oscillation (QBO) on the Northern Hemisphere (NH) polar vortex response to warm El Niño–Southern Oscillation (ENSO) events and the impact of the warm ENSO events on the QBO signal in the NH polar stratosphere have been analyzed using the Middle Atmosphere ECHAM5 model. The experiment setup was designed to include simulations of extended NH winter seasons ...

[1] The response of the equatorial quasi-biennial oscillation (QBO) to zonal-mean ozone perturbations consistent with the 11-year solar cycle is examined using a 2=2 dimensional model of the tropical stratosphere. Unique to this model are wave-ozone feedbacks, which provide a new, nonlinear pathway for communicating solar variability effects to the QBO. Model simulations show that for zonal-mea...

It has often been suggested that the period of the quasi-biennial oscillation (QBO) has a tendency to synchronize with the semiannual oscillation (SAO). Apparently the synchronization is better the higher up the observation extends. Using 45 yr of the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) data of the equatorial stratosphere up to the stratopause, ...