The winter mesopause wind field at 51 ° North

Measurements of mesospheric winds by an imaging Fabry-Perot interferometer located near Calgary (Lat. 51 ° 10′ N, Lon. 114 ° 13′ W) have been obtained from the P1(3) line of the OH(6-2) rotation band for 36 nights during the period of November 1992 to March 1993. The emission layer was observed to have a dominant eastward mean wind as well as a distinct semi-diurnal tidal component signature. Harmonic analysis has been performed on both the individual nights of data as well as on the average monthly winds. The mean winds and semi-diurnal tide of the monthly average winds are found to be typical of the winter mesopause. The daily wind patterns are seen to fluctuate with the mean winds and semi-diurnal amplitude varying by up to a few tens of meters per second. However, these fluctuations are seen to be distributed about the monthly average values. Comparison of these results with previously reported mesospheric winds and model predictions shows general agreement.