Sunday, October 18, 2015
Often, the way that I learn about something new is by investigating something I have seen that I don't understand. Being out in "the field," I almost constantly confront things that motivate me to look into them in more detail. Weather is one of them. I never knew there was anything like a fogbow, for example (think rainbow made of fog), until I experienced one while filming on the river.
On this particular morning, however, I saw a cloud formation that I had never seen before. I took the photo quite some time ago, but I didn't realize there was actually a name for the phenomenon. The corona around the sun exhibits this effect all the time — although a total eclipse is about the only time you could view it.
It is pretty much the same affect that cause waves over open water where the wind over water results in excessive turbulence. In the atmosphere, the wind above the tops of the clouds is moving much faster than at the base, which causes them to develop a rolling motion.
It probably is more common than we realize, but cloud cover masks the phenomenon in many cases. The atmospheric condition is named after scientists Lord Kelvin and Hermann von Helmholtz, who discovered the process that causes the formations.