The Boundary Layer is still cool!
So, this is an image of upper level stratus over the desert in Southern California from last November (2007). While the large scale flow could be approximated as two dimensional, the mountains and conflicting air masses in the region add in three dimensional turbulence. In class today, we had a lovely derivation of energy cascades in three-dimensional turbulent flows, and I was reminded of a poem we learned in my first year of grad school.
Big whirls have little whirls
that feed on their velocity,
and little whirls have lesser whirls,
and so on, to viscosity!– L. F. Richardson (1922)
So my goal in the next week or so is to make a photo of three dimensional turbulence and energy cascades. It might take a while. The forecast is for generally laminar flow the next few days.
I know, I know. I’m a huge nerd.
Oh, you’re not so nerdy. I got caught in a laminar flow the other day and it was hours before the cars started moving again! It caused major three dimensional turbulence and alot of hand gestures! xoxomom
BWAH-HA-HA!! Mom, your are hi-larious!! Thanks for letting me know I’m not as weird as I think I am. Or maybe the fact that your comment made me spit my coffee all over the keyboard means I am that weird!!
You may find the original poem humourous:
Great fleas have little fleas upon their backs to bite ’em, And little fleas have lesser fleas, and so ad infinitum. And the great fleas themselves, in turn, have greater fleas to go on; While these again have greater still, and greater still, and so on.
[1872 A. De morgan Budget of Paradoxes 377]
Hi Doug! Yeah, actually, the original poem was in the notes before Richardson’s. Both great little verses. :) Ah, the fractal nature of the universe. Self-similarity is truly a beautiful thing.