Energetics of an air mass thunderstorm

A nonlinear moist compressible numerical model is used to simulate an air mass thunderstorm generated by a prescribed localized warm bubble. The evolution of the storm is described. Particular attention is focused on two different formulations of the storm energetics. The first is traditional energetics consisting of kinetic, potential, and internal energies. The second uses an Eulerian formulation of available energetics (sometimes called exergetics). This formulation is the nonlinear extension of linear available energetics. It is a generalization of the available energy concept of Lorenz (1955) but, unlike Lorenz, the formulation is valid for nonhydrostatic flows. The exergy is defined relative to an arbitrary isothermal atmosphere in hydrostatic balance with uniform chemical potentials. It is shown that the available exergy can be divided into potential, elastic, and chemical exergies. Each is shown to be positive definite. The evolution of the two energy formulations will be compared and contrasted.