A double magnetic solar cycle and dynamical systems

H. Popova

Department of Physics, Moscow State University, 1 Vorobyovy Gory, Moscow, Russia

Abstract
Various solar activity data have indicated that along with the well-known 22-year cycle there is a shorter periodicity of about 2 years. To simulate this phenomenon, we constructed a dynamical system, which reproduced double-periodic behaviour of the solar cycle. Such nonlinear dynamical system described the solar αω-dynamo process with variable intensities R_α and R_ω of the α-effect and the differential rotation, respectively. We have plotted the time distribution and butterfly diagrams for the poloidal and toroidal magnetic fields with dipole and quadrupole symmetries. The dynamical system with dipole symmetry of the magnetic field reproduces a regime similar to the double cycle at −450 < R_αR_ω < −210. In the case of quadrupole symmetry, this regime exists at −220 < R_αR_ω < −190. Figs 3, Refs 25.