Saturday, December 22, 2007

Hoar frost in Horomerice...

The last few days have been very pretty around our little hovel in Horomerice. The atmospheric conditions have been ideal for the formation of hoar frost, coating the tree branches in white and giving the town a definite winter and Chritmasy look and feel. Hoar frost occurs in Minnesota, but I wouldn't call it common, I suppose because it requires cold temps and high humidity to form. It's usually too dry in Minnesota.

From Wikipedia:Radiation frost (also called hoar frost or, sometimes, hoarfrost) refers to the white ice crystals, loosely deposited on the ground or exposed objects, that form when the air is moist, the wind is weak or absent and surfaces are cold. It is often seen on clear winter nights, especially in valleys and hollows. Hoar frost can form in these areas even when the reported temperature is above the freezing point of water.
One can distinguish between some types of hoar frost, depending on where it forms. For example, air hoar is a deposit of hoar frost on objects above the surface, such as tree branches, plant stems, wires; surface hoar is formed by fernlike ice crystals directly deposited on snow, ice or already frozen surfaces; crevasse hoar consists in crystals that form in glacial crevasses where water vapour can accumulate under calm weather conditions; depth hoar refers to cup shaped, faceted crystals formed within dry snow, beneath the surface.


I took this while driving Noah to the Inrtnational School on Friday morning. I know I probably shouldn't take pictures while driving.














I took this on the walk home from the bus stop in Horomerice.















This tree is the neighbor's yard across the street. I took this as we were getting in the car to pick up Danny at the airport on Friday evening.

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