Some Results of a Trade-Cumulus Cloud Investigation

Cross sections through two trade-cumulus clouds are presented, showing the temperatures, turbulence, and water-vapor content of the clouds and their nearby environment, the cloud slope, and the external wind profile. The two clouds were studied over the Caribbean Sea on the same afternoon in June, 1952, and were in widely differing phases of their life cycles. The measurements were made from a slow-flying aircraft, equipped with sensing instruments and whose behavior as a meteorological tool had been previously studied. Numerous calculations are made from the cross sections, including total and dynamic entrainment, drafts, slopes, and liquid-water content. These are, where possible, checked against the corresponding observations. In addition to testing previously evolved theoretical models, and the usefulness of the steady-state hypothesis, the data provide some evidence concerning the formation and growth of larger tradecumulus clouds from several smaller ones and by successive stages.