The Fog Bow

This morning at CUE Haven we woke up to wonderfully thick fog.  It wasn’t such good news for travellers, but for us it made everything look wonderfully strange  and different.  It didn’t last long, however, because as soon as the sun came up it started burning off.

I decided to drive up to the high ground to get an overview and take some pictures and this was the view from up there:

Normally from here you would see the cottage and nursery and the neighbor’s farms, but this morning everything looked like it was under water.  The fog looked a lot thicker from above than it had been down below and I was thinking how cool it would be to drive back down—like an airplane descending into the clouds as it gets ready to land.

As I drove down I was mildly disappointed that the fog was rapidly dissipating but then I noticed something unusual.  There seemed to be a brighter than usual spot in the fog bank ahead of me.

As I got closer, the white column turned into a white rainbow!

I got back to the cottage and called my wife outside to see the “fog bow.”  Her response was that there is no such thing as a “fog bow.”  I told her that’s what I’d thought.

When we got back to town this afternoon I did some research and found out that there is indeed something called a fog bow and that is what we’d seen.  I have a book, which I’ve never read, called Wonders of the Sky and it told me almost everything I ever wanted to know.

According to the book, fog bows are really called fog bows, but are sometimes referred to as white rainbows.  They are caused by the same mechanism as
rainbows, but because the water droplets that cause fog are so much smaller
than the rain drops which cause rainbows, there is much less refraction and
therefore almost no color.  If a fog bow has any color at all it will be reddish and they are usually twice as thick as rainbows.

A fog bow will occur any time there is a light source behind you and fog in front of you, which is exactly what happened to me this morning.  The book says that on a foggy night the moon can create a “moon bow,” which would definitely be worth seeing.  Apparently, you can get a slightly less impressive moon bow from streetlights or car headlights.  But I don’t think it would be a good idea to stand in a road at night with fog in front of you and car headlights behind you.

I’d never seen or heard of a fog bow before.  I’m not sure if you have, but I hope you get a chance to see one!