Home Current The Polar Vortex Is Causing Striking Solar Phenomena Called 'Sundogs.' Here's What...World NewsCurrentNewsThe Polar Vortex Is Causing Striking Solar Phenomena Called 'Sundogs.' Here's What to KnowJanuary 31, 201995FacebookTwitterPinterestWhatsApp Sundogs form when sunlight refracts off ice crystals in the atmosphere and result in colored spots of light near the sun.