The coupling of planetary waves, tides and gravity waves in the mesosphere and lower thermosphere

Abstract

Between July 1989 and October 1994 near-continuous measurements of the neutral wind at 53.5°N, 3.9°W at an altitude of about 93 km were made by a meteor radar located near Sheffield. The data were analysed to provide a record of the planetary-wave, tidal and gravity-wave activity over this period. Clear evidence was obtained of an interaction between planetary waves and tides, between tides and gravity waves and between planetary waves and gravity waves. In this last case it is possible that this is a two-stage interaction with the planetary waves modulating the amplitude of the tides which then modulate the level of gravity-wave activity.