What's a sun dog? Calgary got a glimpse this week

Sun dogs have been making a mark on Calgary's sky for the last week, thanks in part to the freezing temperatures outside.

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Jesse Rogerson, who works as an educator at the TelusSpark science centre in Calgary,says sun dogs are rare.

"What's happening,it's so cold that you get these ice crystals hanging in the air, and this usually happens ata much higher altitude," he said, like up in cirrus clouds where it's really cold.

"But because Calgary's beenfrigid over the last little while, you get the same ice crystal happening at a much lower altitude. So very close,... basically at the surface of the earth."

"The reason you get these cool structures is because the water has frozen in a specific way.... They call them plates,but it's almost like a leaf, so it's flat like a flat little chunk ofwater frozen in the air. And because of the way they settle, ....like a leaffalling slowlythrough the air, they all align horizontal parallel to the ground."

Rogersonsaysmultiple layers of "floating leaf crystals" all stackon top of each that gives you a makeshift prism, andbecause of the water's chemical structure they bond in a certain waythat makes them have a rainbow effect at a specific angle.

Rogersonsays meteorologists call it diamond dust, but it's also referred to asparheliaor "falsesun."

Solarhalos are slightly different. They are a round ring around the sunwhereno part isbrighter than other areas.

Rogersonthinks theyare a "cool interesting thing you get to notice in the sky"that help usconnect to nature and think about how our atmosphere and sun works.

For more on the science, listen to Rogerson below:

0:39More on the science of sun dogs

More on the science of sun dogs

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