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相关论文: Solar cycle variation in solar f-mode frequencies …

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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…

天体物理学 · 物理学 2015-06-24 Sarbani Basu , H. M. Antia

Frequency and rotational splittings of the solar f-modes are estimated from the GONG data. Contrary to earlier observations the frequencies of f-modes are found to be close to the theoretically computed values for a standard solar model.…

天体物理学 · 物理学 2008-11-26 H. M. Antia

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…

天体物理学 · 物理学 2009-10-31 A. Bhatnagar , Kiran Jain , S. C. Tripathy

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…

天体物理学 · 物理学 2007-05-23 Kiran Jain , S. C. Tripathy , A. Bhatnagar

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…

太阳与恒星天体物理 · 物理学 2019-12-17 Caius L. Selhorst , Juha Kallunki , C. G. Giménez de Castro , Adriana Valio , Joaquim E. R. Costa

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,…

太阳与恒星天体物理 · 物理学 2009-02-11 Kiran Jain , S. C. Tripathy , F. Hill

We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\nu<10 mHz) using the ring diagram technique applied to power spectra obtained from MDI (Michelson Doppler Imager) data.…

天体物理学 · 物理学 2009-10-31 H. M. Antia , Sarbani Basu

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…

太阳与恒星天体物理 · 物理学 2011-02-11 Kiran Jain , S. C. Tripathy , F. Hill

It has been demonstrated that frequencies of f-modes can be used to estimate the solar radius to a good accuracy. These frequencies have been used to study temporal variations in the solar radius with conflicting results. The variation in…

天体物理学 · 物理学 2009-11-07 H. M. Antia

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…

太阳与恒星天体物理 · 物理学 2018-07-18 R. Howe , W. J. Chaplin , G. R. Davies , Y. Elsworth , S. Basu , A. -M. Broomhall

Recent models of variations of the Sun's structure with the 11-year activity cycle by Sofia et al (2005) predict strong non-homologous changes of the radius of subsurface layers, due to subsurface magnetic fields and field-modulated…

天体物理学 · 物理学 2009-11-13 S. Lefebvre , A. G. Kosovichev , J. P. Rozelot

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…

天体物理学 · 物理学 2009-02-10 S. C. Tripathy , F. Hill , K. Jain , J. W. Leibacher

We have analyzed the full set of SOHO/MDI f- and p-mode oscillation frequencies from 1996 to date in a search for evidence of solar radius evolution during the rising phase of the current activity cycle. Like Antia et al. (2000), we find…

天体物理学 · 物理学 2009-11-06 W. A. Dziembowski , P. R. Goode , J. Schou

The questions whether the Sun shrinks with the solar activity and what causes this have been a subject of debate. Helioseismology provides means to measure with high precision the radial displacement of subsurface layers, co-called "seismic…

太阳与恒星天体物理 · 物理学 2018-07-25 Alexander Kosovichev , Jean-Pierre Rozelot

Both GONG and MDI projects have measured {\it p}-mode frequencies of the Sun for more than 7 years. Here we review what we have learnt from the temporal variation of the oscillation frequencies and splitting coefficients.

天体物理学 · 物理学 2007-05-23 S. C. Tripathy

We describe systematic changes in the centroid frequencies and the splitting coefficients as found using data from MDI on board SOHO, covering cycle 23. The data allow us to construct a seismic map of the evolving solar activity -- covering…

天体物理学 · 物理学 2007-05-23 W. A. Dziembowski , Philip R. Goode

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…

太阳与恒星天体物理 · 物理学 2015-05-18 S. C. Tripathy , K. Jain , F. Hill , J. W. Leibacher

Frequency splitting coefficients from Global Oscillation Network Group (GONG) and Michelson Doppler Imager (MDI) observations covering the period 1995--2001 are used to study temporal variations in the solar rotation rate at high latitudes.…

天体物理学 · 物理学 2009-11-07 H. M. Antia , Sarbani Basu

Helioseismology has revealed that the angular velocity of the Sun increases with depth in the outermost 35 Mm of the Sun. Recently, we have shown that the logarithmic radial gradient ($\rm d\ln\Omega/\rm d\ln r $) in the upper 10~Mm is…

太阳与恒星天体物理 · 物理学 2016-11-02 Atefeh Barekat , Jesper Schou , Laurent Gizon

We analyze and interpret SOHO/MDI data on oscillation frequency changes between 1996 and 2004 focusing on differences between activity minimum and maximum of solar cycle 23. We study only the behavior of the centroid frequencies, which…

天体物理学 · 物理学 2009-11-10 W. A. Dziembowski , P. R. Goode
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