TY - JOUR
T1 - Nonlinear dynamical modeling of solar cycles using dynamo formulation with turbulent magnetic helicity
AU - Kitiashvili, I. N.
AU - Kosovichev, A. G.
N1 - Funding Information:
We thank Drs A. Brandenburg, A.A. Ruzmaikin and D.D. Sokoloff for useful discussions and comments. This work was supported by the Center for Turbulence Research (Stanford) and the International Space Science Institute (Bern).
PY - 2009
Y1 - 2009
N2 - Variations of the sunspot number are important indicators of the solar activity cycles. The sunspot formation is a result of a dynamo process inside the Sun, which is far from being understood. We use simple dynamical models of the dynamo process to simulate the magnetic field evolution and investigate general properties of the sunspot number variations during the solar cycles. We have found that the classical Parker's model in this formulation with a standard kinetic helicity quenching cannot represent the typical profiles of the solar cycle variations of the sunspot number, and also does not give chaotic solutions. For modeling of the solar cycle properties we use a nonlinear dynamo model of Kleeorin and Ruzmaikin (Dynamics of the mean turbulent helicity in magnetic field. Magnetohydrodynamics, 1982, 18, 116-122), which takes into account the dynamics of the turbulent magnetic helicity. We have obtained a series of periodic and chaotic solutions for different layers of the convective zone. The solutions qualitatively reproduce some basic observational features of the solar cycle properties, in particular, the relationship between the growth time and the cycle amplitude. Also, on the longer time scale the dynamo model with the magnetic helicity has intermittent solutions, which may be important for modeling long-term variations of the solar cycles.
AB - Variations of the sunspot number are important indicators of the solar activity cycles. The sunspot formation is a result of a dynamo process inside the Sun, which is far from being understood. We use simple dynamical models of the dynamo process to simulate the magnetic field evolution and investigate general properties of the sunspot number variations during the solar cycles. We have found that the classical Parker's model in this formulation with a standard kinetic helicity quenching cannot represent the typical profiles of the solar cycle variations of the sunspot number, and also does not give chaotic solutions. For modeling of the solar cycle properties we use a nonlinear dynamo model of Kleeorin and Ruzmaikin (Dynamics of the mean turbulent helicity in magnetic field. Magnetohydrodynamics, 1982, 18, 116-122), which takes into account the dynamics of the turbulent magnetic helicity. We have obtained a series of periodic and chaotic solutions for different layers of the convective zone. The solutions qualitatively reproduce some basic observational features of the solar cycle properties, in particular, the relationship between the growth time and the cycle amplitude. Also, on the longer time scale the dynamo model with the magnetic helicity has intermittent solutions, which may be important for modeling long-term variations of the solar cycles.
KW - Dynamo
KW - Magnetohydrodynamics
KW - Solar activity
KW - Solar magnetic fields
KW - Sunspots
KW - Turbulence
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U2 - 10.1080/03091920802396518
DO - 10.1080/03091920802396518
M3 - Article
AN - SCOPUS:57949087454
SN - 0309-1929
VL - 103
SP - 53
EP - 68
JO - Geophysical and Astrophysical Fluid Dynamics
JF - Geophysical and Astrophysical Fluid Dynamics
IS - 1
ER -