The Energy of Cyclones

Abstract

WITH reference to Mr. R. M. Deeley's letter on the above subject in NATURE of November 11, may I suggest that the energy of a cyclone is derived from the heat-energy of the earth's surface? If we assume that the air which ascends in the centre of the vortex is less dense on the whole than the air which is at the same temperature outside the vortex, then, since the ascending current must be compensated by a descending current elsewhere, the air will go through a thermodynamic cycle in which positive work will be done at the expense of the heat communicated at the earth's surface.