  Differential rotation is widely supposed to be essential for the dynamo
effects that sustain solar and planetary magnetic fields, but dynamo effects
tend to oppose the flows that drive them, and it is uncertain what drives
differential rotation. The relative sign of the differential rotation and
meridional circulation is not consistent with simple convection modified by
Coriolis forces. We investigate dynamo mechanisms consistent with the observed
solar circulation, and discuss how reactive JxB forces would affect such flows.
We formulate scaling rules that relate the magnetic field strength to mean
rotation and convective heat transport.

Astrophysics;Chaotic Dynamics