Cellular Cumulus Convection in a Moist Atmospheric Layer Heated Below

Abstract

The cumulus model proposed by Asai (1967) is applied to cellular cumulus convection in a moist atmospheric layer uniformly heated below and cooled above. The governing system of equations derived has a steady state solution of cumulus convection independent of initial input disturbances. A preferred mode of steady cumulus convection can be expressed in terms of an amount of heat supply, employing the selection principle that a preferred mode is one for which the lapse rate of temperature is the lowest. An examination of the results shows a coincidence with the feature of cumulus clouds in colder air over warmer water. However, tall vigorous cumulus convection is hardly expected to develop by uniform heating even with a large amount of heat supply.