Morphology of ice crystals growing in free fall at the temperatures between -40 and -140゜C

• Main Author: Gonda, Takehiko
• Language: English
• Published: 1983
• Subjects: Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/record/1505/files/KJ00000012138.pdf

P(論文) For the sake of studying the morphology and the growth mode of single snow crystals forming in the polar regions, ice crystals have been grown in free fall at the temperatures between -40 and -140℃ and their morphology and growth mode have been studied. As a result, in the temperature range from -40 to -70℃, which seem to arise in the polar regions, single ice crystals are predominantly formed at about -40℃, but below about -50℃, polycrystalline ice crystals are predominantly formed; in the case of single ice crystals below 60μm, hexagonal plate-like ice crystals are predominantly formed. The size ratio c/a of plate-like ice crystals growing predominantly at -50℃ hardly depends on crystal size, but that of column-like ice crystals growing at the same temperature increases with increasing crystal size. In addition, the growth mode of column-like ice crystals growing at -50℃ is nearly in agreement with that of diamond dust type ice crystals observed in Antarctica by KIKUCHI and HOGAN (J. Meteorol. Soc. Jpn., 43,359,1979). The growth mode of plate-like ice crystals which may be observed in the polar regions should be investigated, too. departmental bulletin paper