High Rossby-wave activity in austral winter 2002: Modulation of the general circulation of the MLT during the MaCWAVE/MIDAS northern summer program

Abstract

The seasonally and zonally averaged effects of the anomalously strong Rossby-wave activity in austral winter 2002 are estimated by a sensitivity experiment using an idealized general circulation model. The approach focuses on the modulation of gravity-wave saturation via the altered mean winds in the mesosphere and MLT. In the northern summer MLT the effects consist of increased vertical gradients of the mean zonal wind and temperature, as well as downward shifts of the residual circulation and the gravity wave-induced frictional heating. All these signals agree reasonably with observations obtained during the MaCWAVE/ MIDAS program 2002. Copyright 2004 by the American Geophysical Union.