Final Report RAINDROP-SIZE STUDIES

摘要

Qualitative analysis of raindrop-size distributions in heavy showers indicates that some of their prominent features can be explained by the com¬bined effects of wind-shear sorting of drops and of the splashing of large drops upon surface obstructions.nComputational studies which account for the effects of cloud-droplet accretion, raindrop coalescence, and evaporation processes indicate that, in steady-state rain, the origin of large drops lies in snow-aggregation processes above the melting layer. Extending this finding to speculate upon observed differences between heavy shower drop-size distributions in June as compared to October, it is suggested that the relative predominance of the ice-crystal or water-drop processes in convective storms may be indi¬cated by features of the ground-level drop-size distributions.