CONVECTIVE PHENOMENA IN THE ATMOSPHERE

Several convective phenomena in the atmosphere (dry thermals, cumulus and cumulonimbus clouds, etc.) are considered in terms of a simple scheme for the development of convective circulations. Special attention is drawn to the perturbation pressure field and the perturbation wind field under a cumulus and a cumulonimbus. The formation of the thunderstorm high is discussed; it is considered to be due to strong cooling of the air by falling precipitation. The scheme for the development of convective circulations is checked with the aid of pressure-time curves under and outside “rain cells.” The relation between rainfall and pressure hump during the passage of a rain cell is shown. Convective phenomena organized in lines are discussed.