Flux-transport and mean-field dynamo theories of solar cycles

Choudhuri Arnab, arnab@physics.iisc.ernet.in, Indian Institute of Science

Abstract
The most promising theoretical model of the solar cycle at the present time is the flux transport dynamo model in which the toroidal field is produced in the tachocline due to the Sun’s differential rotation, the poloidal field is produced near the surface by the Babcock-Leighton mechanism and the meridional circulation plays a crucial role in transporting the magnetic field. I shall review the current status of mean field calculations based on such a model. Apart from explaining the periodic features of the solar cycle, one of the thrusts of current theoretical research is to understand how irregularities arise in solar cycles. I shall end by summarizing the recent theoretical efforts in this direction.