The evolution of three-peak raindrop size distribution in one- dimensional shaft models. Part I: single-pulse rain

Pulsed input of raindrop packages at the top of one-dimensional shafts, followed by coalescence and breakup during the fall produces, when integrated over time of the whole rainfall, three-peak drop-size distributions (3PDs) at all levels throughout the shaft. The 3PDs are different from the three-peak equilibrium distributions (PEDs) that develop with steady sources of rain. However, for long pulse lengths, the 3PD becomes closer to the 3PED; for short pulse lengths, the large-drop peak is not very prominent for the input of Marshall-Palmer distributions. The diameters corresponding to the maximum concentrations are approxmately the same as those of the 3PED. -from Authors