the upside-down rainbow has a name...

Thanks to my friend Kelly in the US for the following comment about the rainbow in the previous post...

Hi Kelly, that strange sky rainbow is a result of virga (http://en.wikipedia.org/wiki/Virga) When living in Tucson we would see it all the time. Basically, rain falls from the cloud, but doesn't hit the ground. In this case, the sun was shining and, voila, a rainbow!

So, there you go, you learn something every day :o)