Volcanic Particles in The Stratosphere

Abstract

Measurements of intensities of sunlight reflected from a balloon during sunset indicate an above-average concentration of dust at stratospheric levels. Our results for May 1964 (combined with the results obtained by CSIRO from direct sampling of particles from aircraft) may be explained by the presence at 20-km altitude over Victoria of oncentrations of the order of either (i) 500 000 metallic Aitken nuclei per litre, or (ii) a few thousand large aerosols per litre of tl).e types observed in aircraft collections, but with thick coatings of dielectric material, or by the presence of both (i) and (ii).