Nonlinear astrophysical dynamos - Multiple-period dynamo wave oscillations and long-term modulations of the 22 year solar cycle

Abstract

view Abstract Citations (63) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Nonlinear astrophysical dynamos: multiple-period dynamo wave oscillations and long-term modulations of the 22 year solar cycle. Yoshimura, H. Abstract Magnetic oscillations with multiple periods are discovered as natural solutions of the dynamo equation as a direct consequence of the assumption that a time-delay mechanism is intrinsic to the feedback action of a magnetic field on the dynamo process. This phenomenon can be regarded as a hysteretic effect of a nonlinear system. Numerical experiments are performed to study the excitation characteristics of the oscillatory modulations and the internal structure and behavior of the system. The observed long-term modulations of the solar cycle with their two principal characteristics, (i) the occasional occurrence of anomalous eras of no surface activity and (ii) periodicity of the modulations, are discussed and simulated as a guiding example of multiple-period oscillations. The multiplicity of periods of the magnetic oscillations may be universal and may be found in various magnetic phenomena of other astrophysical bodies. Subject headings: hydromagnetics - Sun: activity Publication: The Astrophysical Journal Pub Date: December 1978 DOI: 10.1086/156653 Bibcode: 1978ApJ...226..706Y Keywords: Dynamo Theory; Magnetic Variations; Magnetohydrodynamic Flow; Solar Cycles; Sunspots; Feedback Control; Magnetic Effects; Modulation; Nonlinear Systems; Solar Magnetic Field; Velocity Distribution; Solar Physics; Oscillations:Solar Magnetic Fields; Solar Activity:Solar Magnetic Fields full text sources ADS |