General Circulation of the Atmosphere and Ocean

Abstract

The word circulation here simply refers to motion (sometimes it is used in a narrower sense, to mean motions around closed trajectories, or ‘circulation wheels’). It is convenient to divide atmospheric motions into small-scale motions, with scales L much smaller than the effective thickness H of the atmosphere (defined, for example, by formula (2.6)), meso-scale motions, with L of the order of H or several times larger than H, and large-scale motions, with L ≫ H (Kolesnikova and Monin, 1965). The latter include global circulations, of the zonal and monsoon types, as well as synoptic processes, that is, eddies and Rossby waves, barotropic with scales of the order of L₀ = c₀/f, where c₀ = (gH)^1/2, and baroclinic with scales of the order of L_R = HN/f. The statistical ensemble of large-scale atmospheric motions constitutes the general circulation of the atmosphere.