Halo Complex Over Southern Finland
July 01, 2008
Provided by: Kari Nyman
Summary Author and Editor: Jim Foster, Kari Nyman
The photo above shows part of a grand solar halo display over Nokia, Finland on June 5, 2008, at 08:56 a.m. local time. Almost all solar halos are found approximately 22 degrees from the Sun and are formed by hexagonal ice crystals. These bizarre halos, however, were likely produced from pyramidal shaped ice crystals. Of course, crystals having 4 sides (pyramids) have different refraction and reflection characteristics than do 6-sided crystals. It's not known exactly how these crystals form, but extremely cold temperatures are believed to play a role in their formation. Five distinct halo rings can be identified here; 9 degree (closest to the Sun, which has been intentionally masked), 18 degree, 20 degree, and the 23 and 24 degree halo rings. This was one day when you needed to be outside -- and have your head held high.
According to Guinness Book of World Records the record for multiple solar halos was at least 24 which were seen on January 11, 1999, by scientists at the geographic South Pole.