Ice Pancakes on River Dee

Friday 19th Dec 2014 by theWeather Club

Image: Ice pancakes the size on dinner plates (Source: River Dee Trust)

'Ice pancakes' - common in the Antarctic or Baltic Sea - have been found floating on the River Dee in Scotland.

These are thought to be a result of foam or slush floating on the water which start to freeze, are moved around by eddies and collide with other pieces to form the 'pancakes' seen.

The River Dee Trust said, "The air temperature was colder at night due to the clear-sky conditions but warmer in the day, meaning the discs may have grown at night, then during the day, when the discs softened in the sun, further collisions between the 'pancakes' caused the rims to be pushed up. The next night further growth would have occurred, followed by a new rim the next day."

There was a Weather article in 1999 that explored pancake ice in the Greenland Sea:

"Frazil ice is the name given to the suspension of tiny ice crystals in water which first forms when the sea freezes under turbulent conditions. Pancake ice is a later development where the frazil crystals have frozen together to form small cakes, usually less than 2m across, which acquire raised edges through their frequent wave-induced collisions, each of which pumps frazil ice up over the edge of the cake to create a rim. During the freezing phase the pancakes float within a soup of frazil, from which they are continually growing larger by accretion."

More info >> http://onlinelibrary.wiley.com/doi/10.1002/j.1477-8696.1999.tb06431.x/pdf