Synchronized helicity oscillations: a link between planetary tides and the solar cycle?

摘要

Recent years have seen an increased interest in the question of whether thegravitational action of planets could have an influence on the solar dynamo.Without discussing the observational validity of the claimed correlations, weask for a possible physical mechanism that might link the weak planetary forceswith solar dynamo action. We focus on the helicity oscillations that wererecently found in simulations of the current-driven, kink-type Taylerinstability, which is characterized by an m=1 azimuthal dependence. We show howthese helicity oscillations can be resonantly excited by some m=2 perturbationthat reflects a tidal oscillation. Specifically, we speculate that the 11.07years tidal oscillation induced by the Venus--Earth--Jupiter system may lead toa 1:1 resonant excitation of the oscillation of the alpha-effect. Finally, inthe framework of a reduced, zero-dimensional alpha--Omega dynamo model werecover a 22.14-year cycle of the solar dynamo.