The results of a numerical time int,egration of a hemispheric general circulation model of the atmosphere with moist processes and a uniform earth’s surface has already been published by Manabe, Smagorinsky, and Strickler. In this study, the integration is repeat,ed after halving the midlatitude grid size from approximately 500 to 250 km. This increase in thc resolution of the horizontal finite differences markedly improves the features of the model atmosphere. For example, the system of fronts and the associated cyclone families in the high resolution atmosphere is much more realistic than that in the low resolution atmosphere. Furthermore, the general magnitude and the spectral distribution of eddy kinetic energy are in better agreement with the actual atmosphere as a result of the improvement in resolution. In order to explain these improvements, an extensive analysis of the energetics of both the low and high resolution atmospheric models is carried out. It is shown that, t.hese improvements are due not only to the increase of the accuracy of the finite differences but also to the shift in scale the of dissipation by the nonlinear lateral viscosity toward a smaller scale resulting from t.he decrease in grid size. In the low resolution atmospheric model, the transfer of energy from eddy to zonal kinetic energy is missing because of excessive subgrid scale dissipation at medium xvave numbers, whereas it has significant magnitude in the high resolution atmospheric model. It is speculated that further increase of resolution should improve the results because it tends to separate the characteristic scale of dissipation from tha
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.