Characteristics of cloud drop spectra at different levels and with respectto cloud thickness

Measurements on drop size spectra were made in cumulus clouds over Pune (in land) region on many days during the summer monsoon seasons. In this paper, the measurements in non-raining cumulus clouds made in the years 1984, 198 5 and 1986 at different levels and for different cloud thickness have been studied. In general, the drop size spectra broadened with height and the co ncentration of drops with diameter > 50 mu m (N-L), mean volume diameter (M VD), liquid water content (LWC) and dispersion increased with height while the concentration of drops with diameter < 20 mu m (N-S) and the total conc entration of drops (N-T) decreased with height. The average drop size distr ibutions were unimodal at the lower levels while they were bimodal at the h igher levels. High water contents were confined to drops in the size range 5-25 mu m at both higher and lower levels. The average drop size spectra we re broader and N-L, LWC, MVD and dispersion greater while N-T and N-S small er for thicker clouds (range of vertical extent 1.1-2.1 km) as compared to those for thinner clouds (range of vertical extent 0.3-1.1 km). Water conte nts for the drops > 28 mu m were higher while those for the drops < 28 mu m lower in thicker clouds than in thinner clouds. The average drop size dist ributions were bimodal in the former case, while they were unimodal in the other case.