SPATIAL AND TEMPORAL VARIATIONS OF THE KINEMATIC CHARACTERISTICS IN THE PROPAGATION OF ATMOSPHERIC STATIONARY WAVES

Time-mean global general circulation data are employed to analyze the temporal and spatial variations of the meridional gradient of zonal mean potential vorticity,the critical wavenumber ns for horizontal wave-propagation,and the critical wavenumber Kc for vertical wave-propagation.Thereby the kinematic characteristics in the propagation of atmospheric stationary waves and their annual variations are studied.Results show that in the troposphere ns and Kc usually decrease with the increase of either latitude or altitude.Synoptic and near-resonant Rossby waves could be trapped during their upward and meridional propagations.These characteristics possess prominent annual variations,especially in the Northern Hemisphere.It is found that the spatial and temporal variations of these kinematic characteristics are in good agreement with those of the atmospheric wave patterns.