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Long term trends in solar photospheric fields and solar wind turbulence levels: Implications to the near-Earth space

Published online by Cambridge University Press:  27 November 2018

P. Janardhan Open the ORCID record for P. Janardhan [Opens in a new window] ,
K. Fujiki ,
M. Ingale ,
S. K. Bisoi  and
S. Ananthakrishnan
P. Janardhan
Affiliation:
Physical Research Laboratory, Astronomy & Astrophysics Division, Navrangpura, Ahmedabad, India email: jerry@prl.res.in, mingale@prl.res.in
K. Fujiki
Affiliation:
Institute for Space-Earth Environmental Research, Nagoya, Japan email: fujiki@isee.nagoya-u.ac.jp
M. Ingale
Affiliation:
Physical Research Laboratory, Astronomy & Astrophysics Division, Navrangpura, Ahmedabad, India email: jerry@prl.res.in, mingale@prl.res.in
S. K. Bisoi
Affiliation:
Key Laboratory of Solar Activity, National Astronomical Observatories, CAS, Beijing, China. email: susanta@nao.cas.cn
S. Ananthakrishnan
Affiliation:
Electonics Science Department, Pune University, Pune, India email: subra.anan@gmail.com
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Abstract

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We re-examined solar polar magnetic fields, using ground based synoptic photospheric magnetograms, during solar cycle 24. IThe signed polar magnetic fields showed an unusual hemispheric asymmetry in the polar field reversal process with a single unambigous reversal in the Southern hemisphere around late 2013 while the polar reversal in the Northern hemisphere started earlier around June 2012, but was completed only by the end of 2014. The examination of the unsigned polar magnetic fields in cycle 24 showed a continuing decline of fields in the Northern hemisphere whereas in the Southern hemisphere, it had partially recovered. However, the overall declining trend in solar polar fields, which began in the mid-1990’s, is still in progress. The continued decline seen in solar photospheric fields raises thequestion of whether we are heading towards a Grand or Maunder like solar minimum.

Keywords

Sun: activitySun: magnetic fieldsSun: photosphereSun: heliosphere
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 13 , Symposium S340: Long-term Datasets for the Understanding of Solar and Stellar Magnetic Cycles , February 2018 , pp. 121 - 124
Copyright
Copyright © International Astronomical Union 2018 

References

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