Thursday, 29 January 2009

Please wait while your sky is cleaned

OK, so it was actually a chance grouping of cirrocumulus (the puffy clouds) with cirrostratus (the streaks), but pretty cool, don't you think?

Images copyright 2009 Grace Dalley, all rights reserved.


Mekayla said...

Man I love the NZ sky! You'd think they would need to clean the sky everywhere, but it just doesn't seem to be the case. You know, I should really read that book on clouds that I bought because of you.

Grace Dalley said...


When I first looked at these pictures I assumed the puffy clouds were below the streaky ones but I can see now they are casting a shadow on the streaks, so they must be higher.

It might be that there were ice crystals falling from the cirrocumulus and then getting swept along by a high-level wind, causing the streaks.

Mekayla said...

Ice crystals? But it's Summer there! Don't tell me any differently.

Grace Dalley said...

Cirrus clouds form at 5-10km above the ground. It's so cold up there that all you get is ice crystals, summer or winter!
The awesome thing about ice crystals is that they refract light, and under the right conditions they give ice haloes.
[You can read more about haloes here: ]