February 2, 2015
January ended with a blast of cold and surprisingly beautiful sundogs and a halo.
I happened to look out my window early Saturday morning while managing my email messages and noticed that sundogs were accompanying the rising sun. I didn't think much about the weather and within a few minutes, I was driving out of Winnipeg. Within 5 minutes, I made my first stop on the TransCanada Highway east of Winnipeg and soon realized that it was bitterly cold. At -30 degrees Celsius and with a good wind to boot, it was closer to -40 degrees Celsius. One could barely stay out for a few minutes at a time. I must have stayed out there longer than I should have because my daughter noticed 'splotchy skin' on my face, an indication that I had suffered mild frost bite - the price nature photographers often pay for their craft and art!
A sundog (parhelion) is an atmospheric phenomenon that consists of a pair of bright spots on either side on the sun, often co-occurring with a luminous ring known as a 22° halo. In the last two images, such a halo surrounds the sun. Sun dogs occur when plate-shaped hexagonal ice crystals from very cold weather or from high and cold cirrus clouds refract light. The crystals, which act as prisms, bend the light rays at a minimum of 22°. A halo (complete ring around the sun) occurs if the ice crystals are randomly oriented. However, if the crystals sink through the air and become vertically aligned, the sunlight is refracted horizontally, resulting in sundogs.
I made the following images with a 17-35mm lens set to its widest focal length except for the last image where I used a 24mm PC or tilt/shift lens. Both lens were fitted with a polarizing filter to increase the contrast and saturate the colors. All images, except for the first one, were made near Lorette, Manitoba.
I re-discovered the accompanying image searching through my slide collection recently. Still intrigued by what this image might represent, I picked up my copy of 'Kaleidoscope Sky' by Tim Herd, well known meteorologist and naturalist, and browsed throught the vast collection of most interesting images to see if I could identify this phenomenon. I suspected the image was displaying a phenomemon called 'iridescence'.