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Asymmetry in Solar Torsional Oscillation

Published online by Cambridge University Press:  27 November 2018

B Lekshmi
Affiliation:
Center of Excellence in Space Sciences India, IISER Kolkata, WB-741246, India email: lb15rs016@iiserkol.ac.in
Dibyendu Nandy
Affiliation:
Center of Excellence in Space Sciences India, IISER Kolkata, WB-741246, India email: lb15rs016@iiserkol.ac.in Dept. of Physical Sciences, IISER Kolkata, WB-741246, India email: dnandi@iiserkol.ac.in
H M Antia
Affiliation:
Tata Institute of Fundamental Research, Mumbai email: antia@astro.tifr.res.in
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Abstract

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Solar torsional oscillations are migrating bands of slower and faster than average rotation, which are thought to be related to the Sun’s magnetic cycle. We perform the first long-term study (16 years) of hemispherical asymmetry in solar torsional oscillation velocity using helioseismic data. We explore the spatial and temporal variation of North-South asymmetry using zonal flow velocities obtained from ring diagram analysis of the Global Oscillation Network Group (GONG) Doppler images. We find a strong correlation between the asymmetries of near-surface torsional oscillation with magnetic flux and sunspot number, with the velocity asymmetry preceding in both the cases. We speculate that the asymmetry in torsional oscillation velocity may help in predicting the hemispherical asymmetry in the sunspot cycle.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2018 

References

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