A Helioseismic Perspective on the Depth of the Minimum Between Solar Cycles 23 and 24

被引:20
作者
Broomhall, A. -M. [1 ,2 ]
机构
[1] Univ Warwick, Inst Adv Studies, Coventry CV4 7HS, W Midlands, England
[2] Univ Warwick, Dept Phys, Ctr Fus Space & Astrophys, Coventry CV4 7AL, W Midlands, England
关键词
Helioseismology; observations; Oscillations; solar; Solar cycle; P-MODE FREQUENCIES; QUASI-BIENNIAL PERIODICITY; OSCILLATION FREQUENCIES; TORSIONAL OSCILLATION; DIFFERENTIAL ROTATION; EXTENDED MINIMUM; FLUX TRANSPORT; PECULIAR; DYNAMO; BEHAVIOR;
D O I
10.1007/s11207-017-1068-5
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The minimum in the solar-activity cycle observed between Cycles 23 and 24 is generally regarded as being unusually deep and long. This minimum is being followed by a cycle with one of the smallest amplitudes in recent history. We perform an in-depth analysis of this minimum with helioseismology. We use Global Oscillation Network Group (GONG) data to demonstrate that the frequencies of helioseismic oscillations are a sensitive probe of the Sun's magnetic field: The frequencies of the helioseismic oscillations were found to be systematically lower in the minimum following Cycle 23 than in the minimum preceding it. This difference is statistically significant and may indicate that the Sun's global magnetic field was weaker in the minimum following Cycle 23. The size of the shift in oscillation frequencies between the two minima is dependent on the frequency of the oscillation and takes the same functional form as the frequency dependence observed when the frequencies at cycle maximum are compared with the cycle-minimum frequencies. This implies that the same near-surface magnetic perturbation is responsible. Finally, we determine that the difference in the mean magnetic field between the minimum preceding Cycle 23 and that following it is approximately 1 G.
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页数:15
相关论文
共 52 条
[1]  
[Anonymous], THEORY SOLAR OSCILLA
[2]   SOLAR ROTATION RATE DURING THE CYCLE 24 MINIMUM IN ACTIVITY [J].
Antia, H. M. ;
Basu, Sarbani .
ASTROPHYSICAL JOURNAL, 2010, 720 (01) :494-502
[3]   A new correction of stellar oscillation frequencies for near-surface effects [J].
Ball, W. H. ;
Gizon, L. .
ASTRONOMY & ASTROPHYSICS, 2014, 568
[4]   The peculiar solar cycle 24-where do we stand? [J].
Basu, Sarbani .
ECLIPSE ON THE CORAL SEA: CYCLE 24 ASCENDING (GONG 2012, LWS/SDO-5, AND SOHO 27), 2013, 440
[5]   THINNING OF THE SUN'S MAGNETIC LAYER: THE PECULIAR SOLAR MINIMUM COULD HAVE BEEN PREDICTED [J].
Basu, Sarbani ;
Broomhall, Anne-Marie ;
Chaplin, William J. ;
Elsworth, Yvonne .
ASTROPHYSICAL JOURNAL, 2012, 758 (01)
[6]   A Comparison Between Global Proxies of the Sun's Magnetic Activity Cycle: Inferences from Helioseismology [J].
Broomhall, A. -M. ;
Nakariakov, V. M. .
SOLAR PHYSICS, 2015, 290 (11) :3095-3111
[7]   The Sun's Interior Structure and Dynamics, and the Solar Cycle [J].
Broomhall, A. -M. ;
Chatterjee, P. ;
Howe, R. ;
Norton, A. A. ;
Thompson, M. J. .
SPACE SCIENCE REVIEWS, 2014, 186 (1-4) :191-225
[8]   IS THE CURRENT LACK OF SOLAR ACTIVITY ONLY SKIN DEEP? [J].
Broomhall, A. -M. ;
Chaplin, W. J. ;
Elsworth, Y. ;
Fletcher, S. T. ;
New, R. .
ASTROPHYSICAL JOURNAL LETTERS, 2009, 700 (02) :L162-L165
[9]   Quasi-biennial variations in helioseismic frequencies: can the source of the variation be localized? [J].
Broomhall, A-M. ;
Chaplin, W. J. ;
Elsworth, Y. ;
Simoniello, R. .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2012, 420 (02) :1405-1414
[10]   Solar p-mode frequencies over three solar cycles [J].
Chaplin, W. J. ;
Elsworth, Y. ;
Miller, B. A. ;
Verner, G. A. ;
New, R. .
ASTROPHYSICAL JOURNAL, 2007, 659 (02) :1749-1760