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.