  Two well known turbulent dynamo and MHD oscillation mechanisms are critically
examined and fundamental difficulties are presented. Following new ideas on the
genesis of the solar cycle and activity phenomena are presented. Inevitability
of most likely existence of a combined steady poloidal and toroidal magnetic
field structure in the solar interior. Owing to suitable steady poloidal field
structure, Alfven wave perturbations of long periods (~ 22 yrs) that excite in
the solar core travel first to the poles in both the hemispheres and later
reach the equator. While traveling towards the surface, Alfven wave
perturbations along the weak poloidal field structure in turn perturb the
embedded strong toroidal field structure producing sunspots, especially in the
convective envelope, that travel to the surface due to buoyancy along
isorotational contours. With realistic density structure of the solar interior,
computation of Alfven wave travel times along different field lines of the
poloidal field structure (Hiremath and Gokhale 1995) yields almost similar
periods (~ 22 yr) explaining the constancy of 22 yr period of the odd degree
modes obtained from the Spherical Harmonic Fourier analysis of the surface
magnetic field. The observed quasi-periodicities of solar activity indices in
the range of 1-5 years are explained due to perturbation of the strong toroidal
field structure and, variation of very long period solar cycle and activity
phenomena such as the Maunder and grand minima is explained to be due to
coupling of long period poloidal and toroidal MHD oscillations.
