Preliminary Study of Quasi-Horizontal Eddy Fluxes from Meteorological Rocket Network Data

Abstract

The meridional transport of relative angular momentum by transient eddies is computed from the wind data so far available from the Meteorological Rocket Network for the 25?60 km region. The transport is northward in winter and apparently of sufficient magnitude to account for the formation of the winter polar vortex. It is suggested that the eddies arise in response to the differential heating within the region produced by radiational effects. Zonal available potential energy and its generation are calculated and compared with the kinetic energy. The transformation of eddy kinetic energy to zonal kinetic energy is of the same order of magnitude as the generation of zonal available potential energy. The importance of eddy structures as compared with mean meridional motions appears to be similar to the earlier findings for the troposphere and lower stratosphere. It is concluded that the region from 25?60 km may generate its own kinetic energy in situ in winter and be essentially energetically independent of the troposphere. An alternative explanation for the high temperature of the winter polar mesosphere based upon considerations concerning the eddies is put forward.