So I’m sitting in the sun on my patio, dogs snoozing on the lawn, contemplating the Winter Weather Alert for California mountains from now to next weekend and pondering Climate Models. Wondering about things like how to have the land contour handled, how to compute winds upslope and downslope, how to compute damp valley warm air turning into cold mountain snow with no change of external heating or loss. Just what’s happening now.
Then it occurs to me two things:
1) I could look in the model code I have and see how they do it.
2) I don’t remember seeing anything like ground contours in the GCM code I’ve got (Model II).
Now this matters rather a lot. Much of weather comes directly from valleys and mountains interacting. Everything from all those loverly named downslope winds (like the Santa Anna’s that can make L.A. hot and miserable) to massive ridge lift snow levels.
After all, if climate, as the Warmers claim, is the “long term average of weather” and if weather depends a lot on ground texture and contours (which it clearly does), what is the long term average of model weather if it does NOT have ground contours and mountains in it? Seems to me it will be rather, um, “bogus” from the get go.
So I went off to my postings about GCMs. Did some simple word searches. Does “altitude” or “alt” appear? How about Mountain? Nope. Only in one comment by me about the layers processing.
Read the rest here: