Monday, July 14, 2008

Circumhorizontal arc

Anyone can spot a tiny rainbow among the cirrus cloud?
*hint hint: look above the lamppost!*
If you can't, never mind then, because I think my camera is quite lousy afterall. Anyway, for those who can, what you see is essentially a phenomenon called circumhorizontal arc.

A circumhorizontal arc is created when light is refracted through ice crystals in cirrus clouds. It occurs when the sun is at least 58 degrees above the horizon, and only in presence of cirrus clouds. In contrast to rainbow, circumhorizontal arc is seen on the same side of sky as the sun (so in case you are wondering, the sun in the picture is blocked by the trees).

Below are more pictures of this beautiful phenomenon:
Other related phenomena include iridescent cloud, circumzenithal arc, Kern arc, infralateral arc, supralateral arc, tangent arc, Parry arc, halo, parhelic circle, sundog, etc. in case this is not enough for your knowledge greed :D

I'm still wondering whether this is astro-related. lols

Clear skies,
Anne (: