Kinetic Energy Budget of a Tropical Cyclone

Abstract

An analysis of the kinetic energy budget is made for a tropical cyclone. Horizontal flux convergence constitutes a major energy source. Generation of kinetic energy via cross-contour flow is a persistent sink throughout the pre-storm and growth periods. Dissipation of kinetic energy from subgrid to grid scales is an important source during the pre-storm and growth periods; it acts as the major sink of energy during the decay period. The major contribution to kinetic energy comes from a persistent upper tropospheric jet stream activity throughout the period of the cyclone development. Unlike midlatitude cyclones, a considerable quantity of kinetic energy appears between 850 - 500 hPa layers especially during the growth period. While the behavior of the values of horizontal divergence by nondivergent wind closely resemble to those of total horizontal divergence term, neglecting the divergent part of the wind would clearly lead to a considerable error in the calculation of total horizontal divergence. The mean error in approximation of total horizontal divergence by the nondivergent part during the life cycle of our cyclone is about 36%.