Painted clouds? B.C. residents treated to rare show of ‘cloud iridescence’

A beautiful optical phenomenon was spotted across the South Coast Tuesday afternoon as residents were treated to a show of clouds streaked with rainbow colours.

Global BC senior meteorologist Kristi Gordon said this is called “cloud iridescence,” which is similar to a typical rainbow, but not quite the same.

“These less common rainbows look like they’re painted on the clouds,” Gordon said.

“The reason is the sun’s light is getting diffracted or bent by the water droplets or ice crystals in the clouds. This diffraction causes the sun’s light to separate into its individual colours.”

Gordon described the colours in the cloud iridescence as vivid. For this to occur, the water droplets in the clouds must be a uniform size, which causes a more efficient diffraction of the light, she said..

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