On the Energy Exchange between the Divergent and Rotational Components of Atmospheric Flow over the Tropics and Subtropics at 200 mb during Two Northern

Abstract

The kinetic energy of divergent and rotational flows, and the conversion between these two energy reservoirs, have been computed using the 200 mb fields in the tropics (15°S?20°N) and the subtropics (20?42.5°N)during the summers of 1967 and 1972. The computations are performed in the spectral domain. The numerical results of the conversion between the kinetic energy of divergent and rotational flows and the spectral distribution in the tropics are close to the estimate of generation of kinetic energy by Krishnarmurti and his colleagues. It is suggested that the computation of conversion between the kinetic energy of divergent and rotational flows using the horizontal winds may provide an alternative method of evaluating the generation of kinetic energy in the tropics. The comparison of the kinetic energy of divergent and rotational flows, and conversion between these two energy reservoirs in both the tropics and the subtropics, are also discussed. Effort is also made, to compare the contributions of the standing and transient modes to these energy variables.