What Causes Hoarfrost?

As I mentioned in my post, "When the fog freezes in the trees," we had hoarfrost early yesterday morning. So I dashed out of the house to try to capture it in pictures before it melted, as the day was expected to warm up. I only posted a few pictures initially, as I wanted to take the time to zoom in a bit on some of them to show the frost formation.

I love hoarfrost. It is one of nature's amazing miracles. And I always try to get pictures of it, with somewhat limited success. So I'm going to add some additional photos to this post from Pixabay, such as the following.

Source: Pixabay

The most remarkable thing about hoarfrost is how it coats every little twig and branch. The result is a soft, fuzzy look.

Source: Pixabay

How Does Hoarfrost Form?

I checked a few different explanations, and found this one from dictionary.com to be fairly straight and to the point:

[Hoarfrost is] a deposit of needle-like ice crystals formed on the ground by direct condensation at temperatures below freezing point.

Wikipedia says:

[Hoarfrost ice crystals] form on cold, clear nights when conditions are such that heat radiates out to the open air faster than it can be replaced from nearby sources, such as wind or warm objects.

But I'm not sure it describes how these ice crystals differ from regular ice. Here's one more source, weather.com:

First, to produce any frost, you need water vapor (gaseous form of water) in the air over cold ground with a surface dew point at least as cold as 32 degrees.

When these water vapor molecules contact a subfreezing surface, such as a blade of grass, they jump directly from the gas state to solid state, a process known as "deposition", leading to a coating of tiny ice crystals.

Makes you wonder if you can watch it happen, doesn't it? It turns out you can! Here's a really cool Youtube video:

My Hoarfrost Photos

The rest of these are mine, taken yesterday at the park where I walk my dog, as well as in some neighborhoods. They are not as dramatic as those I shared at the beginning of the post, as it was just a very light frost. With some of the pictures I have zoomed in to get a better look at the crystals.

A little closer:

And one more - my joyful dog, Zoey, romping through the snow.

Thank you very much for visiting my blog! This is my post for #sublimesunday and #beautifulsunday. Thank you to @ace108 for hosting the beautiful Sunday tag, and to @c0ff33a for the sublime Sunday tag.

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