The purpose of this experiment is to observe `Hadley' and `eddying' regimes in a differentially heated, rotating fluid annulus. The experimental arrangement is the same as in GFD Lab VIII (see figure opposite). It consists of a cylindrical plexiglass tank filled with water to a depth of about 15cm and placed on a rotating table. Initially, the water is of uniform temperature. But centered on the rotation axis, we place a metal bucket filled with ice. This sets up a radial temperature gradient (decreasing "poleward") that will drive motions in the tank. Temperature variations in the tank are monitored at strategic positions using thermistors attached to data loggers. Currents are observed using paper dots, potassium permanganate crystals, etc.
'Hadley' and 'eddying' turbulent regimes can be set up in the tank by adjusting the rotation rate, Ω, of the tank - Ω can be ranged from zero to 10 rpm.
We observe the following:
Here is a sequence of images showing the evolution of the flow in the fully turbulent regime:
See the movie:
Experiment XI: Baroclinic Instability of the Thermal Wind (Eddies)