A tangent arc of the halo of 24½ °

✍ Scribed by S. W. Visser; C. T. J. Alkemade

• Book ID: 104571845
• Publisher: John Wiley and Sons
• Year: 1956
• Tongue: English
• Weight: 259 KB
• Volume: 82
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49708235111

✦ Synopsis

Abstract

A remarkable halo complex observed in Germany in 1944 is described and theoretically discussed. There appear to be two possible crystal forms. Only one, however, with an inclination of the pyramidal faces of 25° 14′ fulfills the theoretical conditions. As far as we know there is only one other observation of a tangent are of an uncommon halo (in the Netherlands in 1933). It requires an inclination of the pyramidal face of 54° 44′, just the angle measured by Clarke (1822). In both phenomena we are concerned with similar refraction in similar plate‐shaped ice crystals.