A Reexamination of Limited-Area Available Potential Energy Budget Equations

Abstract

Previous formulations of the limited area available potential energy (APE) budget equations in isobaric coordinates are examined based on computations performed on cyclone systems. It is shown that two terms can be two orders of magnitude greater than other APE and kinetic energy budget terms. These two terms are nearly equal in magnitude and opposite in sign. A new formulation of APE budget equations is developed. The advantages of this formulation over previous ones are that several terms have clearer physical interpretations and all terms in the equation have the same order of magnitude. A comparison of the different forms of the equations is given.