October 27, 2017
Some optical weather phenomena are caused by airborne ice crystals that act like tiny prisms and diffract or bend the light slightly as the light passes through the ice crystals. Sundogs, also known as parhelia or mock suns, can be seen on opposite sides of the 22 degree sun halo just below where the mountain tops meet the sun halo. At the top of the 22 degree sun halo is a faint tangent arc. Also emanating from the sun is a very faint sun pillar (column of light) rising vertically towards the tangent arc but mostly obscured by the ice fog that is prevalent in much of the image. Even with temperatures hovering between -30 and -40 degrees Celsius, much beauty can be photographed in nature if you are comfortable and warmly dressed. Athabasca Glacier on The Icefields Parkway. The Canadian Rocky Mountains, Jasper National Park, Alberta, #canada150 #RockyMountains #CanadianRockies #CanadianRockyMountains #Jasper #JasperNationaPark #Alberta # IcefieldsParkway #sky #halo #sunhalo # parhelia #majesticRockies #mountains #winter #22degreehalo #weather #parhelia #sundogs #tangentarc #sunpillar
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.
It's the middle of March and Winnipeg is again under blizzard conditions! I figured then that it was appropriate to post another ... well ... winter image!
While researching images for a recent calendar submission, I came across this image of a magnificent sun halo accompanied by prominent sundogs. I hadn't seen this image for a few years and decided to 'bring it back'! While all the details were fully captured in the original transparency, the image was rather light in tone and the contrast was fairly low. I scanned the slide and reduced the exposure to bring out the details in the original image.
According to Tim Herd, expert Meteorologist and Naturalist, "halos are created in illuminated ice crystal clouds or a sky filled with falling ice crystals". This 22 degree halo around the sun is one of the most commonly observed. On either side of the sun - sitting on the halo - are the sundogs, also known as parhelia. At the top of the halo, I do beleive we are seeing a circumzenithal arc!
Tim Herd's wonderful book 'Kaleidoscope Sky' (ISBN-10: 081099397X) contains a wealth of information about all kinds of celestical phenomena. 'Kaleidoscope Sky' is my 'go-to Bible' for everything about the sky.
This is one of my favorite images of the Royal Canadian Mint!