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image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Astrophysics and Spa...arrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
Astrophysics and Space Science
Article . 2019 . Peer-reviewed
License: Springer TDM
Data sources: Crossref
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Mid-term periodicities in sunspot area of the Sun during solar cycles 22–24

Authors: Prithvi Raj Singh; C. M. Tiwari; A. K. Saxena; S. L. Agrawal; Akanksha Mishra;

Mid-term periodicities in sunspot area of the Sun during solar cycles 22–24

Abstract

We have studied a monthly variation of the total sunspot areas during solar cycles 22 to 24 (1986–2016). The ∼6 month smoothed variation (FFT filter technique) of the total sunspot areas shows double peaks (solar maximum) with the ascending phase in each cycle for the periods 1989, 1991, 2000, 2002, 2011, and 2014. We have observed mid-term periodicity (intermediate-term) such as the Rieger-type period (∼120 to ∼190 days), quasi-period (∼200 to ∼380 days), and quasi-biennial period (∼1.20 to ∼3.83 years) of the sunspot areas (total sunspot area, and northern and southern hemisphere of the Sun) for the combined solar cycles 22 to 24; using fast Fourier transform (FFT) and Morlet wavelet transformation (WT) techniques (wavelet power spectra and contour plot). The period ∼1.33 year of the southern hemisphere and total sunspot areas have shown the rotation rates on the basis of the convection zone. The quasi-annual period ∼356 days is observed as an important period for the total sunspot area and the southern hemisphere and are absent in the northern hemisphere of the Sun. The periodicities of the total sunspot areas, and southern and northern hemisphere constitute the fifth, sixth and seventh subharmonic of the solar synodic rotation of ∼27 days in the range of the Rieger-type periodicity. The 24th subharmonic of the solar synodic rotation of ∼27 days is highly significant in the total sunspot area and the southern hemisphere of the Sun during the period of our study (1986–2016).

Subjects by Vocabulary

Microsoft Academic Graph classification: Physics Sunspot Synodic day Northern Hemisphere Atmospheric sciences Solar maximum Morlet wavelet Convection zone Variation (astronomy) Southern Hemisphere

Keywords

Astronomy and Astrophysics, Space and Planetary Science

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  • citations
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    7
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Top 10%
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
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citations
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
7
Top 10%
Average
Average