These images of Arctic sea smoke at the entrance to Portsmouth Harbor were taken on January 17, 2007, about 15 minutes after sunrise at the New Castle shore, when the air temperature was +2F and the ocean temperature was about +45F, with the wind averaging about 10 mph with occasional gusts to 20 mph. The images of Arctic sea smoke on the Piscataqua River were taken under similar conditions about 8:30 a.m. on January 26, 2007.

Arctic sea smoke is defined as an evaporation fog that most often occurs when very cold air is moving over relatively warmer water.