Observations

Turbulent convection near the top surface of the cell is characterized by interaction between localized cold downward vortices (plumes) and more extended zones of warm upward flow. For the case of steady rotation (upper row of the table), the number of plumes increases with the rotation rate. In the transient state after impulsive spin-up (middle row of the table), we observe formation of a radially symmetric ring of cold fluid that later evolves into plumes. Impulsive spin-down (bottom row of the table) also produces a radially symmetric feature - a downward plume in the center of the cell. In both cases, the transient processes between two chaotic states exhibit symmetry, presumably due to large-scale Ekman pumping.

Click on the pictures below to see a larger image with statistics.

					Stationary rotation
					Impulsive spin-up
					Impulsive spin-down