A Moist Available Potential Energy Budget for an Axisymmetric Tropical Cyclone

Abstract

The main energy source for the intensification of a tropical cyclone (TC) is widely accepted to be the transfer of energy from the ocean to the atmosphere via surface fluxes. The pathway through which these surface fluxes lead to an increase in the kinetic energy of the cyclone has typically been interpreted either in terms of total potential energy, dry Available Potential Energy (APE), or through the entropy-based heat engine viewpoint. Here, we use the local theory of APE to construct a budget of moist APE for an idealised axisymmetric simulation of a tropical cyclone. This is the first full budget of local moist APE budget for an atmospheric model. In the local moist APE framework, latent surface heat fluxes are the dominant generator of moist APE, which is then converted into kinetic energy via buoyancy fluxes. In the core region of the TC, the inward transport of APE by the secondary circulation is more important than its local production. The APE viewpoint describes spatially- and temporally-varying efficiencies; these may be useful in understanding how changes in efficiency influence TC development, and have a maximum that can be linked to the Carnot efficiency featuring in potential intensity theory.

Complete Edge Smooth Finite Interpolation Method for Limit Upper Limit Analysis of Axisymmetric Structures

“…Axisymmetric structures have strong stability, can withstand huge loads and wind forces, and resist the impact of natural disasters such as earthquakes [19][20]. Axisymmetric mechanics problems belong to a branch of elasticity [21]. The displacement, stress, and strain components are expressed as functions of r and z, independent of angle.…”