Ice cyrstals grown from the vapor at temperatures lower than -15゜C

• Main Authors: Akira Yamashita, Asaharu Asano, Takayuki Ohno, Makoto Wada
• Format: Report
• Language: English
• Published: Department of Earth Science, Osaka Kyoiku University 1984
• Subjects: Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1674; http://id.nii.ac.jp/1291/00001674/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1674&item_no=1&attribute_id=18&file_no=1

By analyzing photomicrographs, the nature of ice crystals grown at temperatures lower than -15℃ was studied first. It was found that in the initial stage of growth, the frequency of occurrence of single-crystalline ice decreases as the temperature decreases although the type of nuclei and method of seedings affects it considerably, and that at temperatures below about -17℃, the lower the temperature the greater the growth rate of polycrystalline ice as compared to that of single-crystalline ice. Second, large ice crystals were grown in an unforced air flow cloud chamber and the nature of polycrystalline ice growing at temperatures lower than about -20℃ was investigated with the following findings : the most prominent polycrystals are those with a sharp growing tip and having a few or many side branches; the most abundant polycrystals are those having a smaller growth rate than the former and being composed of a single or several radially grown branches of assemblages of plates, columns or irregular crystals; radially grown polycrystals are very fragile.