On the Characteristics of Cellular Cumulus Convection

[摘要] A study is made of cellular cumulus convection in a conditionally unstable atmosphere which is unstable for moist ascending motion and stable for dry descending motion. The convection cell under consideration is confined in a cylindrical column : the inside column corresponds to a moist ascending region and the outside annular column corresponds to a dry descending region, while there are an inflow in the lower layer and an outflow in the upper layer.Attention is focused mainly on the evaluation of steady upward heat transport for various values of the size of the cell and the ratio between the ascending and descending areas. A preferred mode of convection is determined by assuming that convection must develop to maximize upward heat transport. It is shown that the present model reduces to a buoyant plume model as a special case when the horizontal scale of the convection cell becomes small compared to its depth and the descending area becomes large.

[学科分类] 大气科学