Experiments with a Stratospheric General Circulation Model: Part IV. Inclusion of the Hydrologic Cycle

Abstract

Abstract The hydrologic cycle has been included in a stereographic model of the Northern Hemisphere previously used as a dry model. The model had 18 vertical levels distributed between the surface and 37.5 km and was run out for annual mean conditions. The model had no topographical features. A remarkably good simulation of many of the zonal mean features of the atmosphere was obtained. The tropospheric and stratospheric jet streams were well reproduced as regards intensity although they were displaced slightly equatorward. The meridional streamfunctions in the model agreed well with observation both in intensity and structure, subject to some distortion of the Hadley cell by the equatorial wall in the model. Considerable improvements were obtained in the representation of the large scale eddy flux of relative angular momentum resulting in good agreement with observation. A detailed discussion is given concerning how the synoptic zonal and meridional wind distributions combine to produce a subtropical jet...