Posted tagged ‘sun’

RING AROUND THE SUN: Changing Weather Ahead

June 28, 2011

Cirrus clouds and a 22° Halo around the sun, with contrails signaling jets passing overhead

Eyes and cameras raised, squinting at the glaring sun, we were amazed as an unexpected phenomenon took place in the sky. There was a perfect halo circling the sun, showing the faint colors of a rainbow. Nature once again put on a great show, this one visible from the park where I was showing my photography in suburban Portland, Oregon.

Sky phenomena are the result of physics, so bear with my numbers and technical information. My photographs show several aspects of the phenomenon, which is known as the “22° Halo.” It was quite wide in the sky, and I barely captured the whole circle with a wide 24mm lens. The rainbow prism is almost precisely at 22° out from the center of the sun. There is a second ring visible in the corners of the photo; this is a 46° Halo, which is supposed to be rarer than the 22° Halo. The sky color inside the 22° Halo is darker than the sky color outside the ring.

A faint second halo appears at 46°

These halos are caused by incoming thin and wispy cirrus clouds, which are often a harbinger of coming rain after a sunny day (indeed, it rained the next day after this halo). These clouds consist of tiny, hexagonal ice crystals; when sunlight passes through the crystals, it refracts out at the 22° angle and separates into the colors of a prism.

That’s the extent of my technical knowledge, but once again, seeing something new in nature revived my sense of wonder. And isn’t that one of the wonderful aspects of being outdoors?

Another view of the wispy cirrus clouds with the sun, signaling a change in the weather 

One word of warning: I was extremely careful in pointing my camera at the sun and looking through the viewfinder not to look directly at the sun. The human retina is fragile and can be burnt beyond repair. Don’t look directly into the sun!

To see my web site, which includes photographic prints for sale, please go to LeeRentz.com

To see thousands of my photographs in large file sizes for use in magazines or other printed materials or electronic media, go to my PhotoShelter Website