AN ILLUSTRATIVE MODEL OF SEASONAL AND INTERANNUAL VARIATIONS OF THE STRATOSPHERIC CIRCULATION

A simple wave-zonal flow interaction model, originally developed by Holten and Mass, is used to illustrate a rudimentary conception of seasonal and interannual variations of the stratospheric circulation. The radiative heating is varied periodically with an annual component to investigate the response of the circulation (i.e. the seasonal variation) to the periodic forcing. The response is qualitatively different depending on the wave forcing from the troposphere. The difference resembles that of the climatological seasonal march between the Northern and the Southern hemispheres. Interannual variation of external conditions is necessary in the present model to obtain interannual variations. -from Author