GROWTH OF POLYCRYSTALLINE FROZEN DROPLETS IN A COLD TEMPERATURE RANGE

Water droplets 20-80μm in diameter were produced from distilled water. They froze into polycrystalline particles, falling freely in a cupper pipe cooled below -30℃. The growth of these polycrystalline frozen droplets was observed by using a diffusion cloud chamber. The crystal shapes were classified into three types, assemblages of plates at temperatures -28 and -33℃, assemblages of plates and columns at temperatures -33 and -35℃ and assemblages of columns at temperatures below -40℃. This result is consistent with the reports that combination of bullets was observed frequently in the polar regions. The effect of the supersaturation on the growth of frozen droplets was also studied