Frost Crystals on Georgian Bay, Ontario
December 26, 2009
The photo at top showing feathery frost crystals was taken near Meaford, Ontario, located on the southern edge of Georgian Bay. From a distance, the surface of the ice over the harbor looked like it was covered with popcorn (bottom photo). Frost of this type may form when a very cold wind blows over relatively moist surface; in this case the frozen surface of a harbor. "Wind frost" usually forms against the direction of the wind. The crystals' orientation on this day indicated that the winds were coming from the northwest -- typical for this time of year in Ontario. These miniature weathervanes grow by the accretion of water vapor onto their protruding surfaces. Photo taken on New Year's Day in 2009.
Meaford, Ontario coordinates: N44.6, W80.583333
Earth Observatory Image of the Day: "Great Lakes Starting to Freeze"