Perfect Conditions for Needle Ice
We may not have gotten the snow fall that was predicted, but we did get freezing temperatures this weekend. I think we can officially say winter has arrived! Sunday morning was bitterly cold. Regardless, I dressed in 3 layers, a big winter coat, hat, gloves and scarf and waddled outside to photograph birds. On the path from the upper kitchen garden to the lower garden, where the ground is often exposed because of high foot traffic, I noticed needle ice had formed overnight.
This happens when there is a high moisture content in the ground (our rain on Friday night) and the soil temperature is above freezing (last week it was 70+ degrees), while the air temperature is below freezing (Hello 18 degrees!).
The subterranean moisture is brought to the surface through capillary action. Often the ice columns push away soil particles as they grow. The soil here is a silty clay which provides enough pore space to conduce water to the surface.
This has occurred in our garden in past years, but these perfect conditions don't always present themselves every year, so it is special when they materialize.
I really wanted to get down on the ground to look closely, not so easy when you're dressed for the polar regions. These ice crystals are really cool! My boys had an impromptu mini-science lesson as I seize these opportunities to teach.
Carefully examining this unique marvel, reveals how the single needles meld together. If the air temperature stays cold enough they will continue to grow taller. These were only a few inches high at the surface and with temperatures climbing slightly above freeing today some of them began to collapse as the afternoon sun warmed us a little.
Similar phenomenons occur on plant stems called frost flowers, on dead wood referred to as hair ice and on small surface rocks then named pebble ice. You've probably experienced one or more of these ice crystal formations in your garden. No matter what the weather conditions are, it is worth getting out in the garden to explore. You never know what you will find!
This happens when there is a high moisture content in the ground (our rain on Friday night) and the soil temperature is above freezing (last week it was 70+ degrees), while the air temperature is below freezing (Hello 18 degrees!).
The subterranean moisture is brought to the surface through capillary action. Often the ice columns push away soil particles as they grow. The soil here is a silty clay which provides enough pore space to conduce water to the surface.
This has occurred in our garden in past years, but these perfect conditions don't always present themselves every year, so it is special when they materialize.
I really wanted to get down on the ground to look closely, not so easy when you're dressed for the polar regions. These ice crystals are really cool! My boys had an impromptu mini-science lesson as I seize these opportunities to teach.
Carefully examining this unique marvel, reveals how the single needles meld together. If the air temperature stays cold enough they will continue to grow taller. These were only a few inches high at the surface and with temperatures climbing slightly above freeing today some of them began to collapse as the afternoon sun warmed us a little.
Similar phenomenons occur on plant stems called frost flowers, on dead wood referred to as hair ice and on small surface rocks then named pebble ice. You've probably experienced one or more of these ice crystal formations in your garden. No matter what the weather conditions are, it is worth getting out in the garden to explore. You never know what you will find!
Great photos! I saw a bit of this over the weekend but I didn't know what it was called.
ReplyDeleteThanks! There are some treasurers to be found when you don't keep a tidy garden and don't get to all the chores, like putting mulch down. Most people don't even notice needle ice until they hear it crunch under their feet.
DeleteThe terms for the ice is new to me, yet we get that formation up here. I never did see it in my garden though. Thanks for the information, Karin. Nice images, it does make for pretty pictures.
ReplyDeleteMost people notice it in their grass when they step on it. Since we have areas where the ground is exposed it is much easier to identify. It's pretty fascinating.
DeleteAmazing! The formations look like ice canyons!
ReplyDeleteGreat analogy. I enjoy studying things at the macro level. It really gives a different perspective on things.
DeleteI have seen frost flowers on pine needles and the stems of assorted plants, but I don't think I have noticed this needle ice before. How interesting! Right now we are having a terrible ice storm, so there is ice of a different kind on absolutely everything! LOL
ReplyDeleteAnd I've never seen frost flowers in my garden. I always admire the photos people post of them. They are really incredible. I hope you survived your ice storm. We get them here too. In fact, we are more likely to have ice storms than snow. We had a big one two years ago where some people were out of power for a week.
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