The 8-hour tide in the Arctic mesosphere and lower thermosphere

[1] An all-sky VHF meteor radar at Esrange (68degreesN, 21degreesE) near Kiruna in Northern Sweden has been used to investigate the 8-hour tide in the Arctic mesosphere and lower thermosphere. We present a climatology of the 8-hour tide over the period October 1999 to April 2001. The tide appears to be a persistent feature of the Arctic atmosphere, although a large day-to-day variability of the tidal amplitude is observed. At times the 8-hour tide reaches amplitudes over 30 m s(-1). The amplitude of the tide increases with height across the observed height range of similar to80-100 km. Monthly mean tidal amplitudes range from