Tag: ice

North Shore on Ice

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by Skip Via
skip@westvalleynaturalists.org

A brief photoessay of some beautifully varied ice, snow and frost manifestations from the north shore of Flathead Lake. As you approach the edge of the open water, marvel at the effects of wave action, multiple thawing and refreezing, snow, wind, and temperature changes on the ice. Also look carefully to find some stunning examples of tiny air bubbles trapped in clear ice as they try to make their way to the surface. Something new in every step.

If you go, wear spikes and bring poles. Also, remember that this area is closed on March 1 to protect critical breeding habitat for a wide variety of birds.

Looking west to the Swan Range.
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Needle Ice

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by Skip Via
skip@westvalleynaturalists.org

Over the past few years, we’ve presented several articles here on our web site dealing with different forms of ice–or more properly, frozen water or water vapor. Here are some:

In this article, we’ll take a look at another icy phenomenon–Needle Ice.

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Hoar Frost or Rime Ice, or Something Else?

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by Skip Via
skip@westvalleynaturalists.org

I woke up on December 29, after two days of dense fog, to see everything–leaves, grasses, fencing wire, pine needles–coated in a beautiful layer of hoar frost.

But wait…hoar frost occurs only in very specific conditions: namely cold, clear, and windless nights with low humidity, when the rapid radiant heat loss from surfaces causes water vapor–not liquid water droplets, as in fog–to form delicate, needle-like crystals on those surfaces. The previous two nights had been anything but cloudless with low humidity. You could feel the cold fog droplets on your face when you walked.

But it sure LOOKS like hoar frost. What’s going on here?

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Hoarfrost or Rime Ice?

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by Skip Via
skip@westvalleynaturalists.org

Editor’s Note: A followup to this article, with more accurate information on how different varieties of frost form, is available here: Hoar Frost, Rime Ice, or Something Else?

A few days ago, driving around West Valley, I remarked on the beauty of the hoarfrost that had coated some Ponderosa pines along the roadside. That got me wondering about the nature of hoarfrost and how it forms. It turns out that some of what I have been calling hoarfrost is, in fact, not hoarfrost, but rather rime ice. The difference is not important for the casual observer, but it can be important meteorologically.

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