Abstract
The evaporation of raindrops in a sub-cloud layer and the change in the state of the layer by it were treated by numerical calculation. The layer is assumed to be uniform in the horizontal. In the model 1 air is assumed to be at rest and in the model 2 vertical airflow with constant velocity is assumed.
Following conclusions were obtained. The amount of evaporated-water in the sub-cloud layer is large beyond expectation. The stability is changed by the cooling due to evapora tion. Pressure dome under a thunder cloud may be explained by the evaporation of raindrops in the sub-cloud layer. The size-spectrum of raindrops gives a significant influence on the changes in the state of the layer. There is considerably large difference between the amount of evaporated-water in updraft and that in downdraft.
