This snowy winter wonderland contains a very rare phenomenon: a fogbow. A fogbow is like a rainbow but instead of all the colours of the spectrum, it appears ghostly white.
Photographer Melvin Nicholson snapped the fogbow while out walking on Rannoch Moor, to the west of Loch Rannoch in Scotland.
As the Atmospheric Optics site explains: “Fogbows are formed by much smaller cloud and fog droplets which diffract light extensively … Fogbows are almost white with faint reds on the outside and blues inside. The colours are so washed out because the bow in each colour is very broad and the colours overlap.”
A fogbow forms in the same way that a rainbow does: the refraction of sunlight in water droplets in the air creates a multicoloured arc. But a fogbow is different because the water droplets in the the fog are very small. Droplets in fogbows have been previously measured at around 60 microns in diameter, which is just a little bit bigger than the width of a human hair (a micron is a thousandth of a millimetre).
Nicholson told Bav Media: "I have never seen a fogbow before and understand that it is very rare.
"It was an amazing thing to witness and can generally only be seen if the sun is behind you when you are looking at it.
"As soon as I saw this wonderful isolated windswept tree, I knew that it had to be framed by the fogbow. Freshly fallen snow set the scene all around.
"It was just beyond magical and one of those days that you'll remember for a long time to come."
Fogbows are most common on hills and mountains and in sea mists, but can be found anywhere where there is thin fog and bright sunshine.
There aren’t many photos of fogbows around, but here are a few we picked out.
Spitsbergen, Norway
Elan Valley, Powys, Wales
Location unknown
Chatham Islands
Burley Moor near Ilkley, Yorkshire
Dobrota, Montenegro
Sea of Okhotsk, near Magadan
Bodega Head, Sonoma Coast, California
Cuillin mountains of Skye, Scotland
Greenland Sea, Arctic Ocean
Alaska
