An Electron Microscope Study of Snow Crystal Nuclei

• Published in: Journal of Glaciology
• Main Author: Nakaya, Ukichiro
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1953
• Subjects: Earth-Surface Processes; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000025661; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000025661

Abstract Snow crystals were received on the collodion film of the holder of an electron microscope, and made to sublimate without melting. These specimens were investigated under an electron microscope. One solid nucleus was always observed in the central portion of a snow crystal. These centre nuclei were of sizes between 0.5 and 8 μ . Most of them were presumed to be kaolin, clay or carbon particles; some were considered to be micro-organisms. In the other parts of snow crystals numerous smaller nuclei were observed, whose dimensions were of the order of those of condensation nuclei. These condensation nuclei were found to be of two kinds, the larger ones most frequently having a diameter of about 0.15 μ , the smaller ones of about 0.05 μ . A new theory was proposed from the data of the electron microscopic studies and those of the conditions of formation of snow crystals. In this theory it is proposed that minute water droplets of 1 μ or so play an important rôls in the process of snow crystal growth.