Torsional Oscillations in Dynamo Models with Fluctuations and Potential for Helioseismic Predictions of the Solar Cycles

Document Type

Article

Publication Date

9-1-2020

Abstract

Using a nonlinear mean-field solar dynamo model, we study relationships between the amplitude of the "extended"mode of migrating zonal flows ("torsional oscillations") and magnetic cycles, and investigate whether properties the torsional oscillations in subsurface layers and in the deep convection zone can provide information about the future solar cycles. We consider two types of dynamo models: models with regular variations of the α-effect, and models with stochastic fluctuations, simulating "long-memory"and "short-memory"types of magnetic activity variations. It is found that torsional oscillation parameters, such the zonal acceleration, show a considerable correlation with the magnitude of the subsequent cycles with a time lag of 11-20 yr. The sign of the correlation and the time-lag parameters can depend on the depth and latitude of the torsional oscillations as well as on the properties of long-term ("centennial") variations of the dynamo cycles. The strongest correlations are found for the zonal acceleration at high latitudes at the base of the convection zone. The model results demonstrate that helioseismic observations of the torsional oscillations can be useful for advanced prediction of the solar cycles, 1-2 sunspot cycles ahead.

Identifier

85091136498 (Scopus)

Publication Title

Astrophysical Journal

External Full Text Location

https://doi.org/10.3847/1538-4357/aba4ad

e-ISSN

15384357

ISSN

0004637X

Issue

1

Volume

900

Grant

80NSSC20K0602

Fund Ref

National Aeronautics and Space Administration

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