A Comparison of Wet and Dry Bent-Over Plumes

Abstract

The theory of moist bent-over plume behavior given by Csanady and by Wigley and Slawson is expanded and clarified to illustrate the differences between moist and dry plume behavior under various atmospheric stability conditions associated with linear gradients of temperature and humidity. If plume types are defined according to the behavior of a dry plume in stable, neutral and unstable conditions, then it is found, for example, that a condensed (or ?wet?) plume rising in an atmosphere with lapse rate equal to the saturated adiabatic lapse rate will behave as a ?neutral? plume, while a dry plume in the same atmosphere will behave as a ?stable? plume. Also, while the condensed portion of a given plume rises according to one stability criterion, the re-evaporated portion may rise according to another.