AN ESSAY ON THE GENERAL CIRCULATION OF THE EARTH5 ATMOSPHERE

Abstract

In this discussion of the general circulation the course of the normal transfer of absolute angular momentum from the belts of easterlies near the equator to the belts of surface westerlies in middle latitudes is studied. It is suggested that the horizontal transfer is brought about by the large-scale troughs and ridges in the mid-troposphere, which are adapted to perform this function by their departure from sinusoidal form. Also, the shapes of the subtropical circulations are found to be such as to produce a transport of angular momentum poleward. It is proposed that the downward flow of angular momentum in the westerly belts is effected by the presence of surface cyclones of the Bjerknes type in these regions. The upward flow in the easterly belts is assumed to be effected through some analogous mechanism, although the details are not clear owing to the scarcity of proper observational data.