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We establish that global solar p-mode frequencies can be measured with sufficient precision on time scales as short as nine days to detect activity-related shifts. Using ten years of GONG data, we report that mode-mass and error-weighted…

Astrophysics · Physics 2009-02-10 S. C. Tripathy , F. Hill , K. Jain , J. W. Leibacher

We analyze intermediate degree p-mode eigenfrequencies measured by GONG and MDI/SOHO over a solar cycle to study the source of their variability. We carry out a correlation analysis between the change in frequencies and several measures of…

Solar and Stellar Astrophysics · Physics 2011-02-11 Kiran Jain , S. C. Tripathy , F. Hill

The parameters of the p-mode oscillations vary with solar activity. Such temporal variations provide insights for the study of the structural and dynamical changes occurring in the Sun's interior throughout the solar cycle. We present here…

Solar and Stellar Astrophysics · Physics 2015-05-20 David Salabert , Rafael A Garcia , Pere L Palle , Antonio Jimenez

Analysis of over 36 years of time series data from the NSO/AFRL/Sac Peak K-line monitoring program elucidates five components of the variation of the seven measured chromospheric parameters: (a) the solar cycle (period ~ 11 years), (b)…

Solar and Stellar Astrophysics · Physics 2015-06-15 Jeffrey Scargle , Stephen Keil , Pete Worden

The recent paucity of sunspots and the delay in the expected start of Solar Cycle 24 have drawn attention to the challenges involved in predicting solar activity. Traditional models of the solar cycle usually require information about the…

Solar and Stellar Astrophysics · Physics 2013-12-05 Mercedes T. Richards , Michael L. Rogers , Donald St. P. Richards

Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every 22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are…

Solar and Stellar Astrophysics · Physics 2024-11-27 Rafael A. Garcia , Sylvain N. Breton , David Salabert , Sushant C. Tripathy , Kiran Jain , Savita Mathur , Eva Panetier

To better understand the influence of the activity cycle on the solar atmosphere, we report the time variation of the radius observed at 37 GHz ($\lambda$=8.1 mm) obtained by the Mets\"ahovi Radio Observatory (MRO) through Solar Cycles 22…

Solar and Stellar Astrophysics · Physics 2019-12-17 Caius L. Selhorst , Juha Kallunki , C. G. Giménez de Castro , Adriana Valio , Joaquim E. R. Costa

The correlation between solar irradiance and the 11-year solar activity cycle is evident in the body of measurements made from space, which extend over the past four decades. Models relating variation in solar irradiance to photospheric…

Solar and Stellar Astrophysics · Physics 2015-07-07 K. L. Yeo , N. A. Krivova , S. K. Solanki

We analyze intermediate degree p- and f-mode eigenfrequencies measured by GONG and MDI/SOHO for a complete solar cycle to study their correlation with solar activity. We demonstrate that the frequencies do vary linearly with the activity,…

Solar and Stellar Astrophysics · Physics 2009-02-11 Kiran Jain , S. C. Tripathy , F. Hill

We present a correlation analysis of GONG p-mode frequencies with nine solar activity indices for the period 1995 August to 1997 August. This study includes spherical harmonic degree in the range 2 to 150 and the frequency range of…

Astrophysics · Physics 2009-10-31 A. Bhatnagar , Kiran Jain , S. C. Tripathy

The Birmingham Solar-Oscillations Network (BiSON) has been collecting data for over 30yrs and so observations span nearly three 11yr solar activity cycles. This allows us to address important questions concerning the solar cycle and its…

Astrophysics · Physics 2008-10-21 A. M. Broomhall , W. J. Chaplin , Y. Elsworth , R. New , G. A. Verner

The frequencies of solar oscillations are known to change with solar activity. We use Principal Component Analysis to examine these changes with high precision. In addition to the well-documented changes in solar normal mode oscillations…

Astrophysics · Physics 2009-11-13 Charles S. Baldner , Sarbani Basu

We have used solar oscillation frequencies and frequency splittings obtained over solar cycles 23, 24 and the rising phase of solar cycle 25 to investigate whether the tachocline properties (jump i.e., the change in the rotation rate across…

Solar and Stellar Astrophysics · Physics 2024-10-04 Sarbani Basu , Wesley Antônio Machado Andrade de Aguiar , Sylvain G. Korzennik

Observations show that the solar p-mode frequencies change with the solar cycle. The horizontal-phase-velocity dependence of the relative frequency change, scaled by mode mass, provides depth information on the perturbation in the solar…

Astrophysics · Physics 2009-11-10 Dean-Yi Chou , Alexander Serebryanskiy

Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (solar rotation) and long-term (solar cycle) changes of the solar spectral irradiance (SSI) between 265-500 nm during the on-going…

Solar and Stellar Astrophysics · Physics 2016-10-26 S. V. Marchenko , M. T. DeLand , J. L. Lean

We have analysed temporal evolution in centroid frequencies and splitting coefficients of solar f-modes obtained from MDI/SOHO. The data were divided into 20 sets covering a period from May 1, 1996 to August 31, 2000. The variation in…

Astrophysics · Physics 2007-05-23 Kiran Jain , S. C. Tripathy , A. Bhatnagar

We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…

Solar and Stellar Astrophysics · Physics 2023-12-20 Mackenzie A. Baird , Sushanta C. Tripathy , Kiran Jain

We investigate the variation of high-degree mode frequencies as a local response to the active regions in two different phases of the solar activity cycle. We find that the correlation between frequency shifts and the surface magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. C. Tripathy , K. Jain , F. Hill

Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results from BiSON have suggested that the response of the mode…

Solar and Stellar Astrophysics · Physics 2018-07-18 R. Howe , W. J. Chaplin , G. R. Davies , Y. Elsworth , S. Basu , A. -M. Broomhall

Solar oscillations frequencies show a distinct change with solar activity. The changes in frequencies can be used to study the time variation of solar structure. We discuss constraints on the changes in solar structure with time as obtained…

Astrophysics · Physics 2007-05-23 Sarbani Basu
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