Meteor radar quasi two-day wave observations over 10 years at Collm (51.3° N, 13.0° E)

Abstract

Abstract. The quasi two-day wave (QTDW) at 82–97 km altitude over Collm (51° N, 13° E) has been observed using a~VHF meteor radar. The long-term mean amplitudes calculated using data between September 2004 and August 2014 show a strong summer maximum and a much weaker winter maximum. In summer, the meridional amplitude is slightly larger than the zonal one with about 15 m s−1 at 91 km height. Phase differences are slightly greater than 90° on an average. The periods of the summer QTDW vary between 43 and 52 H during strong bursts, while in winter the periods tend to be more diffuse. On an average, the summer QTDW is amplified after a maximum of zonal wind shear which is connected with the summer mesospheric jet and there is a possible correlation of the summer mean amplitudes with the backgound wind shear. QTDW amplitudes exhibit considerable inter-annual variability, however, a clear relation between the 11 year solar cycle and the QTDW is not found.