NUMERICAL EXPERIMENTS IN SYMMETRIC AND ASYMMETRIC MOTIONS IN THE BAROTROPIC PRIMITIVE EQUATION MODEL ATMOSPHERE

Three numerical experiments have been carried out by using a spectral barotropic primitive equation mo-del.It is found that the results obtained are quite similar to those with the barotropic filtered model.Themain results read as follows:(1)In the case with symmetric orography or without orography,if the motion is symmetric(with re-spect to the equator,the same is true hereafter)at the initial instant,then it would be symmetric afterwards.(2)The antisymmetric orography distribution could cause antisymmetric motion,and the original sym-metric motion might become asymmetric.In order to explain the above results,it has been proved that they are theoretically valid.And it is foundthat if the motion is antisymmetric at the initial instant,then it would become asymmetric.Therefore,nopure antisymmetric motion could be maintained.