"Finland has had a spate of elliptical halos over the last few days produced by ice crystals precipitating out of low clouds. The ones Leivo photographed are superb," says atmospheric optics expert Les Cowley. "Elliptical halos are rare and we do not understand how they are formed. A popular theory is that hexagonal plate-shaped crystals with very blunt pyramidal ends make them. But ray tracing simulations using these crystals do not reproduce the halo’s fine detail properly. Moreover, these crystals are physically unrealistic because crystal faces follow lines of atoms in the crystal lattice – blunt pyramidal ends do not! The mystery remains."
this was taken on feb 17 2011, in finland. ifyou go to space weather archive put in feb 17 for the date, at the bottom of the picture, there are smll numbers, they are for additional pictures.
Comments
Space weather explains this is ice crystals..
"Finland has had a spate of elliptical halos over the last few days produced by ice crystals precipitating out of low clouds. The ones Leivo photographed are superb," says atmospheric optics expert Les Cowley. "Elliptical halos are rare and we do not understand how they are formed. A popular theory is that hexagonal plate-shaped crystals with very blunt pyramidal ends make them. But ray tracing simulations using these crystals do not reproduce the halo’s fine detail properly. Moreover, these crystals are physically unrealistic because crystal faces follow lines of atoms in the crystal lattice – blunt pyramidal ends do not! The mystery remains."