Axel Brandenburg, Gustavo Guerrero
Some selected concepts for the solar activity cycle are briefly reviewed.
Cycle modulations through a stochastic alpha effect are being identified with
limited scale separation ratios. Three-dimensional turbulence simulations with
helicity and shear are compared at two different scale separation ratios. In
both cases the level of fluctuations shows relatively little variation with the
dynamo cycle. Prospects for a shallow origin of sunspots are discussed in terms
of the negative effective magnetic pressure instability. Tilt angles of bipolar
active regions are discussed as a consequence of shear rather than the Coriolis
force.
View original:
http://arxiv.org/abs/1111.3351
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