Winds and Wave Motions to 110 km at Mid-Latitudes. III. Response of Mesospheric and Thermospheric Winds to Major Stratospheric Warmings

Abstract The behavior of winds at 52°N, 107°W (Saskatoon, Canada) at altitudes to ∼110 km during major stratospheric warmings of 1969–70,1970–-71 and 1972–73 winters and a minor warming in December 1972, is studied. The zonal component of flow above the stratosphere is found to be affected to varying altitudes; in January 1970 the normal eastward flow was reversed to westward at all altitudes from the surface to ∼110 km. The pattern of winds is reasonably consistent with current suggestions that at middle and high latitudes the mesosphere cools as the stratosphere warms, and that the mesosphere warms subsequent to its cooling. Examples of mesospheric wind perturbations either as precursors of stratospheric warmings or independent of warmings, are also given.