CZA abbrev. Circum-zenithul Arc (n):

ever had atmospheric optics described over the phone?

i'm in the pub - in the back garden...
the sun's really low and there are wispy clouds everywhere...
there's this amazing patch of rainbow...
it's about a hand-span from the sun....
above the sun you have to see this...
it's like an upside down rainbow!

that kind of phonecall just makes my day! good thing i had my camera with me, and a handy rooftop to stand on :)