Many of you sent photos of the sun pillar on Sunday morning through the Peaks2Plains Weather App and through social media. Often times in the dense and cold air from the arctic, ice crystals will be suspended in the atmosphere. Here are a couple of them.
I always appreciate when you take the time to send me videos and pictures of our weather – both when it’s pretty and when it’s nasty. They help me to cover and explain why our weather does what it does!
Here’s how the sun pillars form. It takes pretty specific conditions to get the horizonal, tiny crystals of ice hanging in the atmosphere. When water freezes it does so in certain shapes depending on several factors like air temperature and vapor pressure. When we see pillars either form the sun or streetlights, there are thin plates with hexagonal faces. When this ice drifts down through or is suspended in the air, it’s usually pretty horizontal.
Ice easily reflects light (high albedo!) so the flat plate shapes bounce the light around and reflects off of other ice crystals. Really, it’s like a bunch of mirrors floating in the sky. The light hitting these “mirrors” gets reflected up and up, or down and down, depending where the light source is, and the result is a light column in the sky.
You sent me examples from the sun, but the moon, streetlights, really anything can cause the same thing!
