Inferring Quadrupolar Dynamo Mode from Sunspot Statistics

Abstract

Observations of long-term north-south asymmetry in solar activity demand the equator-symmetric (quadrupolar) mode be present in the solar magnetic field in line with the dominant antisymmetric (dipolar) mode. This paper proposes treating the sunspot area as a proxy for subsurface toroidal magnetic flux to infer the quadrupolar mode of the solar dynamo from sunspot data. Toroidal pseudo-fluxes (PF) in the northern and southern hemispheres are defined as a signed sunspot area with plus or minus sign prescribed to them in accord with the Hale's sunspot polarity rules. Statistical correlation analysis and wavelet analysis of so-defined PFs reveal quadrupolar oscillations with a period of about 16 yr and amplitude of about 0.17 relative to the amplitude of the dominant 22-yr dipolar mode.

arXiv comment5 pages, 6 figures

References in corpus (10)

• The Solar Cycle
• Full--Sphere Simulations of a Circulation--Dominated Solar Dynamo: Exploring the Parity Issue
• Effects of the scatter in sunspot group tilt angles on the large-scale magnetic field at the solar surface
• Solar parity issue with flux-transport dynamo
• Double-peaks of the solar cycle: An explanation from a dynamo model
• Origin of the hemispheric asymmetry of solar activity
• Is the Hemispheric Asymmetry of Monthly Sunspot Area an Irregular Process with Long-Term Memory?
• Dynamo Model for North-South Asymmetry of Solar Activity
• Can the long-term hemispheric asymmetry of solar activity result from fluctuations in dynamo parameters?
• Impact of rogue active regions on hemispheric asymmetry