Tidal features in the wintertime mesospheric temperature and neutral winds recorded at Resolute Bay, Canada (74.68°N, 94.90°W)

The mesospheric temperature and neutral winds have been monitored from the Early Polar Cap Observatory, in the northern high latitude (Resolute Bay; 74.68°N, 94.90°W), Canada by a Michelson interferometer (MI) from 1997 to 2001 and a Fabry–Perot interferometer (FPI) from 1998 to 1999, respectively. The MI observes the nightglow OH (3–1) bands to derive temperature and airglow emission rate of the upper mesosphere. The FPI instrument provides the neutral wind data. For this study, we analyzed multi-year data taken from the above site and performed spectral analysis to retrieve tidal wave information. From the Lomb–Scargle spectral analysis of the measured temperatures, we find significant tidal oscillations at 8, 12, and 24 h periods. On the other hand, variations in the neutral wind are dominated by the 12- and 24-h period waves. Because of their periods and persistence, the observed oscillations are most likely of tidal origin, i.e. s=0 non-migrating tides, for the temperature, which are known to have their maximum amplitudes at the pole based on past observations. However, we cannot rule out the other tidal components may also contribute to the observed oscillations. For the winds, at least the observed 12-h oscillation could be a solar-migrating tide with zonal wave number 2; again there may be some small contribution from other tidal components.