Cumuli structure at Various Stages of Development

Abstract

The results of simultaneous measurements of thermal structure (convective column temperature and dimensions), of the concentration of droplets of various sizes (diameters from 3?70 ?m), and liquid water content in clouds, which during a period of a day undergo various development stages, are considered. It is shown that maximum droplet concentrations of all dimensions are observed in the convective columns at points where temperature excess maxima relative to environmental cloud air occur. However, this relation between drop number and temperature excess exists only in growing clouds. Approximate estimates are also obtained of the droplets of critical size, above which they are observed, as a rule, only in convective columns. It is found, in individual clouds at a relatively early stage of development, that droplets are found with diameters ≥70 ?m. The diameters of cloud droplets, which give the maximum contribution to cloud liquid water content as well as to the relative quantity of environmental cloudless air entrained, increase in developing clouds as the cloud thickness increases.