Planetary wave coupling - observations and theory

Research on the forcing of atmospheric planetary waves, their propagation, their interactions with the mean zonal flow, and their influence on ozone transport is reviewed. Previous GCM and idealized modeling work on the forcing mechanisms for extratropical planetary waves in the troposphere and middle atmosphere has given contradictory results. Some studies indicate that orographic forcing is dominant which others have indicated that the forcing from diabatic heating is at least of equal importance. Some analyses of observed planetary wave structures support the latter view. The evolution of planetary wave propagation from the pioneering work of Charney and Drazin is reviewed. In particular, the question of whether zero wind lines absorb or reflect is emphasized. -from Author