Simultaneous and colocated observation of winds and tides by MF and meteor radars over London, Canada (43°N, 81°W), during 1994–1996

Abstract

Simultaneous and colocated comparisons of winds and tides by MF and meteor VHF radars have been made in the 85–94 km height range from July 1994 to June 1996 over London, Ontario, Canada. Results have been obtained for every month of the year. From these comparisons it is concluded that, in general, the MF spaced antenna technique and the meteor method both provide reliable means for synoptic studies of neutral air motions in the height range 85–94 km, at timescales of greater than 12 hours, and therefore are valuable tools in middle atmospheric research. However, we do find that some parameters seem to be estimated with greater precision than others. In particular, the measurements of the zonal long‐term wind variations, and the semidiurnal tide in both the zonal and meridional directions, seem particularly robust and reliable, while there is somewhat less consistency between measurements of the zonal diurnal tide and the meridional monthly mean winds. The former problem is very likely to be an artifact of the strong diurnal variation in meteor count rates. However, we cannot claim that our meridional monthly mean wind agreement is always good, and these discrepancies deserve further investigation.