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

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 m 2 s −2 near 84 km to 16 m 2 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 −1 over the 83–90 km height interval. The anisotropy is considerable and may suggest the presence of standing waves.