Algebraic quantification of an active region's contribution to the solar cycle

Abstract

The solar dipole moment at cycle minimum is considered to be the most successful precursor for the amplitude of the subsequent cycle. Numerical simulations of the surface flux transport (SFT) model are widely used to effectively predict the dipole moment at cycle minimum. Recently an algebraic method has been proposed to quickly predict the contribution of an active region (AR) to the axial dipole moment at cycle minimum instead of SFT simulations. However, the method assumes a bipolar magnetic region (BMR) configuration of ARs. Actually most ARs are asymmetric in configuration of opposite polarities, or have more complex configurations. Such ARs evolve significantly differently from that of BMR approximations. We propose a generalized algebraic method to describe the axial dipole contribution of an AR with an arbitrary configuration, and evaluate its effectiveness compared to the BMR-based method. We employ mathematical deductions to obtain the generalized method. We compare the results of the generalized method with SFT simulations of observed ARs, artificially created BMRs, and ARs with more complex configurations. We also compare the results with that from the BMR-based method. The generalized method is equivalent to the SFT model, and precisely predicts the ARs' contributions to the dipole moment. The method has a much higher computational efficiency than SFT simulations. Although the BMR-based method has similar computational efficiency as the generalized method, it is only accurate for symmetric bipolar ARs. The BMR-based method systematically overestimates the dipole contributions of asymmetric bipolar ARs, and randomly miscalculate the contributions of more complex ARs. The generalized method provides a quick and precise quantification of an AR's contribution to the solar cycle evolution, which paves the way for the application into the physics-based solar cycle prediction.

arXiv comment9 pages, 5 figures. Accepted for publication in A&A

References in corpus (17)

• Solar cycle prediction
• The crucial role of surface magnetic fields for the solar dynamo
• Effects of the scatter in sunspot group tilt angles on the large-scale magnetic field at the solar surface
• Surface flux transport modeling for solar cycles 15--21: effects of cycle-dependent tilt angles of sunspot groups
• An Updated Solar Cycle 25 Prediction with AFT: The Modern Minimum
• Predictability of the solar cycle over one cycle
• Limits to solar cycle predictability: Cross-equatorial flux plumes
• Modeling Solar Cycles 15 to 21 Using a Flux Transport Dynamo
• Modeling the Sun's open magnetic flux and the heliospheric current sheet
• Nonlinear mechanisms that regulate the solar cycle amplitude
• Changes of the solar meridional velocity profile during cycle 23 explained by flows towards the activity belts
• Towards an algebraic method of solar cycle prediction I. Calculating the ultimate dipole contributions of individual active regions
• How good is the bipolar approximation of active regions for surface flux transport?
• Activity Complexes and A Prominent Poleward Surge During Solar Cycle 24
• Different contributions to space weather and space climate from different big solar active regions
• Effect of morphological asymmetry between leading and following sunspots on the prediction of solar cycle activity
• Towards an algebraic method of solar cycle prediction II. Reducing the need for detailed input data with ARDoR

Cited by in corpus (10)

• Surface Flux Transport on the Sun
• Physical Models for Solar Cycle Predictions
• Sunspot tilt angles revisited: Dependence on the solar cycle strength
• Comparison of physics-based prediction models of solar cycle 25
• Towards a live homogeneous database of solar active regions based on SOHO/MDI and SDO/HMI synoptic magnetograms. I. Automatic detection and calibration
• Toward a live homogeneous database of solar active regions based on SOHO/MDI and SDO/HMI synoptic magnetograms.II.parameters for solar cycle variability
• Algebraic Quantification of the Contribution of Active Regions to the Sun's Dipole Moment: Applications to Century-scale Polar Field Estimates and Solar Cycle Forecasting
• Minimal Roles of Solar Subsurface Meridional Flow in the distributed-shear Babcock-Leighton Dynamo
• Observation-Based Iterative Map for Solar Cycles. I. Nature of Solar Cycle Variability
• Ultra-fast simulations of the solar dipole and open flux