A: As the remnants of Superstorm Sandy approached us on Oct. 29, people in Wisconsin observed a halo on two consecutive nights. These halos resulted from the ice clouds generated from the storm. A halo is a whitish ring that encircles but does not touch the sun or moon. It is an optical phenomenon that owes its existence to the bending of light by ice crystals, much like the ?rainbow crystals? you may hang in your windows.
Office of Strategic Communication