Kinetic energy liberated in an unstable layer

Kinetic energy is released when an unstable super‐adiabatic layer of constant lapse‐rate ϵΣ rights itself (where Σ is the adiabatic lapse‐rate and ϵ > I). The average kinetic energy can be computed analytically by Margules's method or graphically on the tephigram. By Margules's method a good approximate formula for the resulting average velocity is shown in this paper to be v = constant × Ap/II {(ϵ‐I)Θ)½, where II and Θ are the mean pressure and temperature of the column and Δp is the pressure difference between the top and bottom of the column. The method of the tephigram gives the average energy to be equivalent to one‐sixth the area of a parallelogram of which the diagonals are the initial and final temperature curves of the column. Some examples are numerically evaluated by these methods and the results show close agreement with values previously calculated by a longer and more laborious method by Littwin.