Thursday, July 29, 2010

orographic terminology

My friend Joe asks a specific cloud question:

Joe: Okay, an earth sciencey sort of question for you. In greenland I often saw cloud formations that sort of formed a belt half way up a cliff, e.g.,

Roughly speaking, my question is "does that have a cool name?" and "what's up with that?" Okay, that's two questions. :)

Can you explain? Is there a name for that kind of cloud position/type?

(I did tell him why the cloud formed there - but beyond that, I know not.)

Joe's going back to Greenland in a few days to take more pictures. Check out the rest of his Above the Arctic Circle work, -- he's good at making geography visible.


quasigeostrophy said...

I'd venture a guess that if it's orographic, as it appears, it's only getting halfway up because of the limited amount of moisture in the air. The forced lift condenses everything out too early to reach the peak of the ridge. I don't think it has a cool name, other than orographic cumulus. It looks a lot like a horizontal convective roll cloud, but the presence of the ridge makes me think it's not due to a roll.

Joe said...

Indeed, it was interesting to see them on the previous trip, several times on fjord walls. Nifty in any case, thanks. :)