Learning about glories

2010-11-29 16:22:27.000 – Brian Clark,  Observer and Meteorologist

Double glory!! Well, not exactly…

I am the sort of person that like to learn new things. I’m happy to say that most days, I manage to learn something new, even if it is random and rather pointless. Today, I learned something about an optical phenomena that we see from time to time on the summit: a glory.

A glory is created when sunlight backscatters off of a cloud layer (clouds with uniform droplet size work best) to its source, creating a ring of color on the cloud layer that looks similar to a rainbow. On Mount Washington, we often see this phenomena on an undercast layer during the 2 or 3 hours after sunrise, forming around either the shadow of the mountain or our tower, on the undercast. I’ve seen it happen more times than I can remember, so it’s not necessarily uncommon to see, although it is always beautiful. This morning’s was a little different in the sense that I was able to clearly discern multiple rings while in the past I had only ever seen a singular ring of color.

In my head (and on our page on Facebook) I was thinking of it as a triple glory since I could see three rings. My fellow observer Mike Finnegan was even able to see four rings. As it turns out, there’s not technically such a thing as a double, triple, or quadruple glory. The reason: there is always numerous rings associated with a halo. In fact, the number of rings goes to infinity. The difference is that sometimes it isn’t possible to see more than one ring. Also, some people’s eyes will see more than one ring while others’ won’t. This is different from a rainbow, where there is not necessarily always more than one bow.

Although I was only technically wrong, I’m a technical person, so I like to be technically right. Make sense? It does in my head. Anyways, I hope now YOU’VE learned something new today!

Two websites with some info on glories:

Wikipedia

Atmospheric Optics

Brian Clark,  Observer and Meteorologist