Giant hygroscopic nuclei in the atmosphere and their role in the formation of rain and hail

The results of two years' observations of the hygroscopic particle content of the surface air at five places in West Pakistan show that sea-salt particles of mass up to 10−9 gram may penetrate far into the interior of continents. Larger particles appear rather more numerous inland than would be expected if their sole source is the ocean, and some other possible sources are discussed. The observed particle concentrations in the Punjab suggest that the fragmentation of large droplets may play an important part in the formation of heavy rain in this area.