During the Czech halo observers meeting in Kuncice, high clouds created some good displays. This odd radius halo complex was seen on 14. August. It shows 9,° 18°, 20°, 22-24° and 35° halos. Judging from the non-uniform intensity distribution of some of the halos (9° and 20° halos being brightest on the sides), this display was caused by poorly oriented columnar pyramid crystals. It's also interesting that 20° halo is brighter than 18° halo. This type of occurence is uncommon.This is stacked image processed by Roman Manak and Patrik Trncak. Original photos were taken by Martin Popek.
Guess it could be called 9 colum arc as well (with faint 9 halo).Then we would have also 20 column arc (with faint 20 halo). It up to your taste.
VálaszTörlés