Abstract: The validity of the geostrophic approximation is examined for the Northern Hemisphere from the lower troposphere to the stratopause in January, using a general circulation model. Substantial errors are found when the ...

Abstract: Amplitude vacillation is studied using a spectral version of the two-level quasi-geostrophic model in a ?-plane channel. The parameters are chosen so that only a single wave may be unstable to the undisturbed basic state. ...

Abstract: Amplitude vacillation is studied using a spectral version of the two-level quasi-geostrophic model in an f-plane channel. The numerical results are compared to those of a weakly nonlinear asymptotic theory of amplitude ...

Abstract: The influence of the polar night jet structure in determining the wave properties in the troposphere is examined using a general circulation model (GCM). It is shown that there are significant differences in the tropospheric ...

Abstract: The mean circulation of the winter stratosphere depends strongly on the interaction between the planetary waves and the zonally averaged flow. The theory of wave-mean flow interactions is used to determine the acceleration ...

Abstract: The thermal balance of the NCAR Community Climate Model is examined using the zonally averaged temperature tendency equation of the model. The perpetual January and perpetual July control simulations are used to determine ...

Abstract: Results are studied from a numerical experiment using a version of the NCAR Community Climate Model with high vertical resolution and extending from the surface to the lower mesosphere. The model was integrated for 370 ...

Abstract: The dynamics of vacillation is examined for the case where several waves are unstable and the wave-mean flow interactions are shown to be the same as in the case where only one wave is unstable, as has been done previously. ...

Abstract: Dynamical measures of the climate (e.g., winds, eddy fluxes) simulated by a general circulation model are compared at different horizontal and vertical resolutions for the December, January, and February period. The ...

Abstract: The effects of an artificial upper boundary on the climate of a general circulation model are examined using two versions of the model. The complete model has 26 levels extending from the surface to 0.1 mb (?65 km) and the ...