Solar large-scale magnetic field and cycle patterns in solar dynamo

Abstract

We compare spectra of the zonal harmonics of the large-scale magnetic field of the Sun using observation results and solar dynamo models. The main solar activity cycle as recorded in these tracers is a much more complicated phenomenon than the eigen solution of solar dynamo equations with the growth saturated by a back reaction of the dynamo-driven magnetic field on solar hydrodynamics. The nominal 11(22)-year cycle as recorded in each mode has a specific phase shift varying from cycle to cycle; the actual length of the cycle varies from one cycle to another and from tracer to tracer. Both the observation and the dynamo model show an exceptional role of the axisymmetric ${\ell }_5$ mode. Its origin seems to be readily connected with the formation and evolution of sunspots on the solar surface. The results of observations and dynamo models show a good agreement for the low ${\ell }_1$ and ${\ell }_3$ modes. The results for these modes do not differ significantly for the axisymmetric and nonaxisymmetric models. Our findings support the idea that the sources of the solar dynamo arise as a result of both the distributed dynamo processes in the bulk of the convection zone and the surface magnetic activity.

arXiv comment12 pages, 12 Figures, accepted in MNRAS

References in corpus (31)

• The Solar Cycle
• The case for a distributed solar dynamo shaped by near-surface shear
• Sunspot group tilt angles and the strength of the solar cycle
• Prediction of the strength and timing of sunspot cycle 25 reveal decadal-scale space environmental conditions
• Bipolar Magnetic Regions on the Sun: Global Analysis of the SOHO/MDI Data Set
• Solar Magnetic Field Reversals and the Role of Dynamo Families
• Towards A Mean-Field Formulation Of The Babcock-Leighton Type Solar Dynamo. I. Alpha Coefficient Versus Durney's Double Ring Approach
• On the Formation of Active Regions
• A Solar Dynamo Model Driven by Mean-Field Alpha and Babcock-Leighton Sources: Fluctuations, Grand-Minima-Maxima and Hemispheric Asymmetry in Sunspot Cycles
• Multiple dynamo modes as a mechanism for long-term solar activity variations
• Solar Grand Minima and random fluctuations in dynamo parameters
• Advances in mean-field dynamo theory and applications to astrophysical turbulence
• Mechanism of spontaneous formation of stable magnetic structures on the Sun
• A Stochastically Forced Time Delay Solar Dynamo Model: Self-Consistent Recovery from a Maunder-like Grand Minimum Necessitates a Mean-Field Alpha Effect
• Turbulent transport coefficients in spherical wedge dynamo simulations of solar-like stars
• The Sun's Preferred Longitudes and the Coupling of Magnetic Dynamo Modes
• The Origin of Parity Changes in the Solar Cycle
• On the Origin of Solar Torsional Oscillations and Extended Solar Cycle
• A 3D kinematic Babcock Leighton solar dynamo model sustained by dynamic magnetic buoyancy and flux transport processes
• An update of Leighton's solar dynamo model
• Modelling variability of solar activity cycles
• The magnetic field vector of the Sun-as-a-star. II. Evolution of the large-scale vector field through activity cycle 24
• Effects of large-scale non-axisymmetric perturbations in the mean-field solar dynamo
• Torsional Oscillations in Dynamo Models with Fluctuations and Potential for Helioseismic Predictions of the Solar Cycles
• The mean electromotive force resulting from magnetic buoyancy instability
• Can the long-term hemispheric asymmetry of solar activity result from fluctuations in dynamo parameters?
• Does nonaxisymmetric dynamo operate in the Sun?
• Cyclic variations in the main components of the solar large-scale magnetic field
• A new look at sunspot formation using theory and observations
• Helioseismic Constraints and Paradigm Shift in Solar Dynamo
• The magnetic helicity density patterns from non-axisymmetric solar dynamo

Cited by in corpus (6)

• Turbulent processes and mean-field dynamo
• Effects of Emerging Bipolar Magnetic Regions in Mean-field Dynamo Model of Solar Cycles 23 and 24
• Comparison of solar activity proxies: eigen vectors versus averaged sunspot numbers
• Zonal harmonics of solar magnetic field for solar cycle forecast
• Migrating Dynamo Waves and Consequences for Stellar Current Sheets
• Hemispheric analysis of the magnetic flux in regular and irregular solar active regions