Comments on: Fog, coal and ducks http://www.wqed.org/birdblog/2007/11/19/fog-coal-and-ducks/ A Bird Watcher's View of the World Tue, 06 Jan 2009 07:55:52 +0000 http://wordpress.org/?v=2.6.3 By: Kate http://www.wqed.org/birdblog/2007/11/19/fog-coal-and-ducks/#comment-52 Kate Sun, 02 Dec 2007 14:41:47 +0000 http://www.wqed.org/birdblog/2007/11/19/fog-coal-and-ducks/#comment-52 I looked up hoarfrost & learned there are many kinds. According to Wikipedia, this version is: "Advection frost (also called wind frost) refers to tiny ice spikes forming when there is a very cold wind blowing over branches of trees, poles and other surfaces. It looks like rimming the edge of flowers and leaves and usually it forms against the direction of the wind. It can occur at any hour of day and night." What was unusual about this frost is that it formed spikes that pointed into the wind. This is counter-intuitive. We are much more familiar with ice forming on the leeward side as the wind blows rain/sleet away from the branches. I looked up hoarfrost & learned there are many kinds. According to Wikipedia, this version is:
“Advection frost (also called wind frost) refers to tiny ice spikes forming when there is a very cold wind blowing over branches of trees, poles and other surfaces. It looks like rimming the edge of flowers and leaves and usually it forms against the direction of the wind. It can occur at any hour of day and night.”

What was unusual about this frost is that it formed spikes that pointed into the wind. This is counter-intuitive. We are much more familiar with ice forming on the leeward side as the wind blows rain/sleet away from the branches.

]]> By: Mark Bowers http://www.wqed.org/birdblog/2007/11/19/fog-coal-and-ducks/#comment-19 Mark Bowers Fri, 23 Nov 2007 00:41:57 +0000 http://www.wqed.org/birdblog/2007/11/19/fog-coal-and-ducks/#comment-19 Kate, I think this type of frost is called hoarfrost. I don't think I have seen it very often. Mark Kate,

I think this type of frost is called hoarfrost. I don’t think I have seen it very often.

Mark

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