A Thermodynamic Analysis of Cumulus Convection

The Water Content of Cumuliform Cloud

“…In most reported observations it has been noted that the value of the liquid water content at any level above the base of the cloud has been less than the amount that would be released by simple adiabatic lifting of the cloud air and condensation of the surplus water vapour. STOMMEL (1947,1951) followed by AUSTIN and FLEISHER (1948), HOUGHTON and CRAMER (1951) and MALKUS (1949, ~g j z a , 1952 b) put forward and elaborated a theory of entrainment of the environmental air into the cloud which could account for the observed deficiency in liquid water. In no case were suitable observations of cloud water content available to give quantitative support to the theory.…”

Airborne lidar observations of long-range transport in the free troposphere

“…Material that has been injected into the free troposphere above the mixed layer can be horizontally transported over long distances without significant dilution due to mixing from below (12). The interaction of the elevated haze layer with local mixed layers and clouds was reconstructed by using available surface, upper air, and radar observations, and model estimates of cloud top heights (13) with cloud top verification from infrared satellite imagery (14). A representative time-height history of mixed layer, cloud top, and cloud base heights below the calculated haze layer trajectory is shown in Figure 4.…”

“…A representative time-height history of mixed layer, cloud top, and cloud base heights below the calculated haze layer trajectory is shown in Figure 4. This figure shows average local values for observed cloud base height along with model estimates for cloud top height (13), mixed layer height determined by the encroachment method neglecting condensation, and the nocturnal inversion height (15). As illustrated in Figure 4, our calculations indicate that subsequent long-range transport has occurred over a lower level of fair weather cumulus convective debris.…”

The Design, Execution, and Evaluation of a Weather Modification Experiment

“…The second and third equations were developed by Austin and Fleisher [8] to evaluate changes of cloud temperature due to mixing, resaturating the mixed air, and the temperature change from condensation. The fourth equation is the continuity equation for water substance which includes loss of water in turbulent mixing.…”