Why does the Sun's torsional oscillation begin before the sunspot cycle?

Abstract

Although the Sun's torsional oscillation is believed to be driven by the Lorentz force associated with the sunspot cycle, this oscillation begins 2--3 yr before the sunspot cycle. We provide a theoretical explanation of this with the help of a solar dynamo model having a meridional circulation penetrating slightly below the bottom of the convection zone, because only in such dynamo models the strong toroidal field forms a few years before the sunspot cycle and at a higher latitude.

4 pages 3 figures. Unfortunately there were some errors in the figures which appeared in PRL. We are putting the corrected figures here. The text is the same as the text in PRL. An erratum is being sent to PRL pointing out the errors in the figures. We would like to thank Bidya Binay Karak for assistance in preparing the corrected figures

References in corpus (5)

• Predicting solar cycle 24 with a solar dynamo model
• Solar activity forecast with a dynamo model
• Flux-transport dynamos with Lorentz force feedback on differential rotation and meridional flow: Saturation mechanism and torsional oscillations
• On the penetration of meridional circulation below the solar convection zone
• How does the shape and thickness of the tachocline affect the distribution of the toroidal magnetic fields in the solar dynamo?

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• A Theoretical Model of the Near Surface Shear Layer of the Sun
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• Large-Scale Dynamos Driven by Shear-Flow-Induced Jets
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• A theoretical model of torsional oscillations from a flux transport dynamo model