Measurements from 2002–2011 by three independent satellite instruments, namely MIPAS, SABER, and SMR on board the ENVISAT, TIMED, and Odin satellites are used to investigate the inter-annual variability of stratospheric and mesospheric O 3 volume mixing ratio (vmr) inside the Antarctic polar vortex due to solar and geomagnetic activity. In this study, we individually analysed the relative O 3 vmr variations between maximum and minimum conditions of a number of solar and geomagnetic indices (F10.7 cm solar radio flux, Ap index, ≥ 2 MeV electron flux). The indices are 26 day averages centred at 1 April, 1 May, and 1 June while O 3 is based on 26 day running means from 1 April–1 November at altitudes from 20–70 km. During solar quiet time from 2005–2010, the composite of all three instruments reveals an apparent negative O 3 feedback associated to the geomagnetic activity (Ap index) around 1 April, on average reaching amplitudes between −5 and −10% of the respective O 3 background. The O 3 response exceeds the significance level of 95% and propagates downwards throughout the polar winter from the stratopause down to ∼ 25 km. These observed results are in good qualitative agreement with the O 3 vmr pattern simulated with a three-dimensional chemistry-transport model, which includes particle impact ionisation.