On the zonally-symmetric circulation in two-level quasi-geostrophic models

A. WIIN NIELSEN

Abstract

The zonally-averaged steady state circulation in Phillips' general circulation model is determined using the same physical parameters as in the original experiment. The approximate zonally-symmetric state is determined both by spectral procedures and by solving the differential equations directly. The results are compared with a similar determination of the same circulation carried out by Charney resulting in very large wind velocities. It is concluded that the new results are more realistic than the extremely intensive circulation determined by Charney, but also that the zonal steady state has zonally averaged velocities of a few hundred meters per second. Employing a more realistic determination of the atmospheric averaged heat budget resulting in a Newtonian form of the heating when the Boltzman terms are linearized gives finally acceptable results in general agreement with Chameys later results.

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