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Related papers: Solar Rotation Rate During the Cycle 24 Minimum in…

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We present an analysis of the variability of the solar oscillation spectrum during solar cycle 23 and its extended minimum. We use simultaneous observations of the low-degree solar p modes collected by the space-based, Sun-as-a-star GOLF…

Solar and Stellar Astrophysics · Physics 2010-04-19 D. Salabert , R. A. Garcia , P. L. Palle , S. J. Jimenez-Reyes , A. Jimenez

The latitudinal distributions of the yearly mean rotation rates measured respectively by Suzuki in 1998 and 2012 and Pulkkinen $\&$ Tuominen in 1998 are utilized to investigate internal-cycle variation of solar differential rotation. The…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. J. Li , J. L. Xie , X. J. Shi

We examine the frequency shifts in low-degree helioseismic modes from the Birmingham Solar-Oscillations Network (BiSON) covering the period from 1985 - 2016, and compare them with a number of global activity proxies well as a…

Solar and Stellar Astrophysics · Physics 2017-07-26 R. Howe , G. R. Davies , W. J. Chaplin , Y. Elsworth , S. Basu , S. J. Hale , W. H. Ball , R. W. Komm

In this work we introduce a new way of binning sunspot group data with the purpose of better understanding the impact of the solar cycle on sunspot properties and how this defined the characteristics of the extended minimum of cycle 23. Our…

Thirty-four years of WSO (Wilcox Solar Observatory) and thirteen years of SOHO/MDI (Michelson Doppler Imager on the Solar and Heliospheric Observatory) magnetograms have been studied to measure the east-west inclination angle, indicating…

Solar and Stellar Astrophysics · Physics 2010-03-23 Leyan Lo , Todd Hoeksema , Phil Scherrer

Using data from the Global Oscillations Network Group (GONG) that covers the period from 1995 to 1998 we study the change in frequencies of solar oscillations with solar activity. From these frequencies we attempt to determine any possible…

Astrophysics · Physics 2015-06-24 Sarbani Basu , H. M. Antia

Over 54 years of hourly mean value of solar wind velocity from 27 Nov. 1963 to 31 Dec. 2017 are used to investigate characteristics of the rotation period of solar wind through auto-correlation analysis. Solar wind of high velocity is found…

Solar and Stellar Astrophysics · Physics 2019-09-25 Kejun Li , W. Feng

The structure of electric current and magnetic helicity in the solar corona is closely linked to solar activity over the 11-year cycle, yet is poorly understood. As an alternative to traditional current-free "potential field"…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. R. Yeates , J. A. Constable , P. C. H. Martens

This paper presents the analysis of 3D evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data has been obtained from interplanetary scintillation (IPS)…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. K. Manoharan

Data obtained by the GONG and MDI instruments over the last seven years are used to study how solar dynamics -- both rotation and other large scale flows -- have changed with time. In addition to the well known phenomenon of bands of faster…

Astrophysics · Physics 2009-11-07 Sarbani Basu , H. M. Antia

The data of sunspot numbers, sunspot areas and solar flare index during cycle 23 are analyzed to investigate the intermediate-term periodicities. Power spectral analysis has been performed separately for the data of the whole disk, northern…

Solar and Stellar Astrophysics · Physics 2009-11-16 Bhuwan Joshi , P. Pant , P. K. Manoharan

We investigate the behavior of the intermediate-degree mode frequencies of the sun during the current extended minimum phase to explore the time-varying conditions in the solar interior. Using contemporaneous helioseismic data from GONG and…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. C. Tripathy , K. Jain , F. Hill , J. W. Leibacher

The current cycle minimum appears to be deeper and broader than recent cycle minima, and this minimum appears similar to the minima in the early 1900s. With the best-ever solar irradiance measurements from several different satellite…

Solar and Stellar Astrophysics · Physics 2010-03-25 Thomas N. Woods

In this paper, I review the results of 3-D evolution of the inner heliosphere over the solar cycle #23, based on observations of interplanetary scintillation (IPS) made at 327 MHz using the Ooty Radio Telescope. The large-scale features of…

Solar and Stellar Astrophysics · Physics 2011-04-04 P. K. Manoharan

The last solar minimum was, by recent standards, unusually deep and long. We are now close to the maximum of the subsequent solar cycle, which is relatively weak. In this article we make comparisons between different global (unresolved)…

Solar and Stellar Astrophysics · Physics 2015-07-13 A. -M. Broomhall , V. M. Nakariakov

This deep, extended solar minimum and the slow start to Cycle 24 strongly suggest that Cycle 24 will be a small cycle. A wide array of solar cycle prediction techniques have been applied to predicting the amplitude of Cycle 24 with widely…

Solar and Stellar Astrophysics · Physics 2010-03-23 David H. Hathaway

The flare activity and the ultraviolet emission of the sun during its 24-th cycle are analysed. As compared to cycles 21-23, where the most powerful flares were observed during the decay phase, in cycle 24 the greatest number of powerful…

Solar and Stellar Astrophysics · Physics 2017-11-29 E. A. Bruevich , G. V. Yakunina

Solar quasi-biennial oscillations with period range 0.6 to 4 years, are prominent in records of solar activity. Here we show that the 1.6 year quasi-biennial oscillation in solar activity has the exceptional feature of phase inversion…

Solar and Stellar Astrophysics · Physics 2021-10-27 Ian R. Edmonds

We have examined how the characteristics of the tachocline -- i.e., the change in rotation rate $\delta\Omega$, or the "jump", the position of the midpoint of the tachocline, $r_d$, and the width of the tachocline, $w_d$, -- change as a…

Solar and Stellar Astrophysics · Physics 2026-03-04 Sarbani Basu , Sylvain G. Korzennik , Sushanta C. Tripathy

The Sun's polar magnetic fields change their polarity near the maximum of sunspot activity. We analyzed the polarity reversal epochs in Solar Cycles 21 to 24. There was a triple reversal in the N-hemisphere in Solar Cycle 24 and single…

Solar and Stellar Astrophysics · Physics 2019-10-16 Mykola I. Pishkalo