VHF radar observations of the dynamics of the summer polar mesopause region

Abstract

Observations of the dynamics of the mesopause region over the Norwegian island of Andøya (69°N, 16°E) made during 2 days in summer 1987 using the mobile SOUSY VHF (53.5 MHz) Doppler Radar are reported. Measurements of the three mean wind components and the 12- and 24-hour horizontal tidal components, as well as preliminary estimates of the component of the total upward flux of density-normalized horizontal momentum in the SW–NE plane and the anisotropy of the horizontal wind are presented for the 83- to 90-km height interval. Values of the component of the density-normalized flux in the SW–NE plane for the 10-min to 48-hour period range, after the 12-and-24-hour tidal components have been removed, vary from −1 m2 s−2 near 84 km to 16 m2 s−2 near 89 km. The major contribution is from the 10-min to 12-hour period range. The corresponding mean flow acceleration takes a mean value of −136 m s−1 d−1over the 83–90 km height interval. The anisotropy is considerable and may suggest the presence of standing waves.