Stratospheric temperature eleven years variations: Solar cycle influence or stroboscopic effect

32 years of Northern Winter Stratospheric data (January and February) at the 30 mb level when sorted according to the west phase of the quasi-biennial oscillation at the 50 mb level appear to exhibit variations similar to the ones of the 11 years solar cycle. It is shown in this note that the sampling according to the phase of the quasi-biennial oscillation is fortuitously very close to a sorting according to the odd or the even years. As a result, assuming that the temperature is itself modulated by a quasi-biennial oscillation (27.7 months), a stroboscopic effect (aliasing) might be generated by the sampling and might lead to an apparent variation with a period close to the one of the solar cycle