Modelling variability of solar activity cycles

被引:26
作者
Kitchatinov, L. L. [1 ,2 ]
Mordvinov, A., V [1 ]
Nepomnyashchikh, A. A. [1 ]
机构
[1] Inst Solar Terr Phys, Lermontov Str 126A, Irkutsk 664033, Russia
[2] Pulkovo Astron Observ, St Petersburg 196140, Russia
基金
俄罗斯基础研究基金会;
关键词
dynamo; Sun: activity; Sun: magnetic fields; MAIN-SEQUENCE DWARFS; GRAND MINIMA; SUPERFLARES OCCUR; MAGNETIC-FIELDS; DYNAMO MODEL; FLUCTUATIONS; MAXIMA; TRANSPORT; SUN;
D O I
10.1051/0004-6361/201732549
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Context. Solar activity cycles vary in amplitude and duration. The variations can be at least partly explained by fluctuations in dynamo parameters. Aims. We want to restrict uncertainty in fluctuating dynamo parameters and find out which properties of the fluctuations control the amplitudes of the magnetic field and energy in variable dynamo cycles. Methods. A flux-transport model for the solar dynamo with fluctuations of the Babcock-Leighton type alpha-effect was applied to generate statistics of magnetic cycles for our purposes. The statistics were compared with data on solar cycle periods to restrict the correlation time of dynamo fluctuations. Results. A characteristic time of fluctuations in the alpha-effect is estimated to be close to the solar rotation period. The fluctuations produce asymmetry between the times of rise and descent of dynamo cycles, the rise time being on average shorter. The affect of the fluctuations on cycle amplitudes depends on the phase of the cycle in which the fluctuations occur. Negative fluctuations (decrease in alpha) in the rise phase delay decay of poloidal field and increase the cycle amplitude in toroidal field and magnetic energy. Negative fluctuation in the decline phase reduces the polar field at the end of a cycle and the amplitude of the next cycle. The low amplitude of the 24th solar cycle compared to the preceding 23rd cycle can be explained by this effect. Positive fluctuations in the descent phase enhance the magnetic energy of the next cycle by increasing the seed poloidal field for the next cycle. The statistics of the computed energies of the cycles suggest that superflares of >= 10(34) erg are not possible on the Sun.
引用
收藏
页数:8
相关论文
共 52 条
[1]   THE TOPOLOGY OF THE SUNS MAGNETIC FIELD AND THE 22-YEAR CYCLE [J].
BABCOCK, HW .
ASTROPHYSICAL JOURNAL, 1961, 133 (02) :572-&
[2]   Understanding Solar Cycle Variability [J].
Cameron, R. H. ;
Schuessler, M. .
ASTROPHYSICAL JOURNAL, 2017, 843 (02)
[3]   The turbulent diffusion of toroidal magnetic flux as inferred from properties of the sunspot butterfly diagram [J].
Cameron, R. H. ;
Schuessler, M. .
ASTRONOMY & ASTROPHYSICS, 2016, 591
[4]   SUPERFLARE OCCURRENCE AND ENERGIES ON G-, K-, AND M-TYPE DWARFS [J].
Candelaresi, S. ;
Hillier, A. ;
Maehara, H. ;
Brandenburg, A. ;
Shibata, K. .
ASTROPHYSICAL JOURNAL, 2014, 792 (01)
[5]   Dynamo Models of the Solar Cycle [J].
Charbonneau, Paul .
LIVING REVIEWS IN SOLAR PHYSICS, 2010, 7 (03)
[6]  
CHOUDHURI AR, 1995, ASTRON ASTROPHYS, V303, pL29
[7]   Predicting solar cycle 24 with a solar dynamo model [J].
Choudhuri, Arnab Rai ;
Chatterjee, Piyali ;
Jiang, Jie .
PHYSICAL REVIEW LETTERS, 2007, 98 (13)
[8]   Origin of Grand Minima in Sunspot Cycles [J].
Choudhuri, Arnab Rai ;
Karak, Bidya Binay .
PHYSICAL REVIEW LETTERS, 2012, 109 (17)
[9]  
DSILVA S, 1993, ASTRON ASTROPHYS, V272, P621
[10]   ON A BABCOCK-LEIGHTON DYNAMO MODEL WITH A DEEP-SEATED GENERATING LAYER FOR THE TOROIDAL MAGNETIC-FIELD [J].
DURNEY, BR .
SOLAR PHYSICS, 1995, 160 (02) :213-235