aphrodisiac gig

Have you ever noticed that the sky on the red (out) side of a rainbow is darker than on the blue (inside). When there's a double bow, the strip in between is darker than the rest of the sky - due to all of the misdirected light busy making up the colours and the inner glow. This dark patch is named after its first decsriber, Alexander of Aphrodisias. The top of this 22 degree halo (possibly with a parry gull) is also darker on the red side. I guess this is also Alexander at work...

(A week of ice haloes...)