Yesterday was cold - today is colder. Last night the temperature got down to 18 F (-8 C) and this morning many things were covered in frost - including our car. On the way to the car I noticed that the mole hills in our lawn looked different. And they certainly were different. They were all covered in needle frost.
This is caused when the air temperature is below freezing and the ground isn't. The moisture in the ground freezes and pushes upward in the shape of needles, starting a few inches below the surface of the soil, and twisting above. The soil has to be very damp - which our was - from previous weeks of rain and when the air is colder the needles of ice begin to form. There have been instances where needle ice grew to 16 inches (41 cm) - but mine is only about 1.5" (3.8 cm) to 2" (5.08 cm).
There are many names for needle ice - ice castles, frost castles, ice fringes, ice filaments, ice flowers, ice ribbons, frost flowers, and rabbit ice. I couldn't find any explanation as to why it might be called rabbit ice - but the other names are quite descriptive.
When I was growing up I was told this was hoar frost - but I see that it is not hoar frost at all, and I even taught my kids that it was hoar frost - and I shall have a hard time changing names - but I like the names ice castles and frost flowers, and I think of fairies when I see this kind of frost.
But whatever we call it, it is majestic and wonderously interesting. I had to get down close to the ground to get these photos - and it was very cold and the camera lens kept fogging up. What a glorious way to begin by seeing this fabulous ice in the mole hills.
As the sun comes up, the fairies go back to their homes to wait for the next morning to see if there is more ice.
And a little boy comes along and crunches the ice - the most fun of all. I still like to walk on the ice and feel it crunch, crunch crunch beneath my shoes. In a few hours it was all melted and only soggy mole hills remained - waiting for another frosty cold night to come again.
What is your favorite wintery cold thing?