scholarly journals On the magnetic field required for driving the observed angular-velocity variations in the solar convection zone

2012 ◽  
Vol 428 (1) ◽  
pp. 470-475 ◽  
Author(s):  
H. M. Antia ◽  
S. M. Chitre ◽  
D. O. Gough
Keyword(s):  
Magnetic Field ◽  
Angular Velocity ◽  
Convection Zone ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Velocity Variations ◽  
The Magnetic Field

scholarly journals Mean-Field Magnetohydrodynamics of the Solar Convection Zone

1976 ◽  
Vol 71 ◽  
pp. 305-321
Author(s):  
F. Krause
Keyword(s):  
Magnetic Field ◽  
Velocity Field ◽  
Convection Zone ◽  
Solar Surface ◽  
Mean Field ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Random Character ◽  
Physical Quantities ◽  
The Magnetic Field

Observations of the solar surface show that some of the physical quantities, especially the velocity field and the magnetic field, show random character.

scholarly journals Distributions of the Sources of the Magnetic Field During the Double Magnetic Cycle

1998 ◽  
Vol 185 ◽  
pp. 463-464
Author(s):  
Elena E. Benevolenskaya
Keyword(s):  
Magnetic Field ◽  
Solar Magnetic Field ◽  
Convection Zone ◽  
Coronal Holes ◽  
Magnetic Cycle ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
The Magnetic Field ◽  
Dynamo Process ◽  
Longitudinal Structures

The longitudinal and latitudinal distributions of the solar magnetic field have been investigated by many authors see e.g. (Bumba and Howard 1969; Gaizauskas et. al. 1983). The main longitudinal structures such as active longitudes, sector boundaries in the solar wind, and coronal holes appear to be the consequence of non-symmetric magnetic modes (Stix 1971; Ivanova and Ruzmaikin 1977) and can be explained within the framework of dynamo models. According to these models, solar magnetic fields are generated by helicity and differential rotation in the solar convection zone (Parker 1979) and the linear dynamo process may generate a carrier frequency ωc (ωc = 2π/T, T = 22 yr

scholarly journals Simulating Solar Global Magnetism in 3-D

2012 ◽  
Vol 10 (H16) ◽  
pp. 101-103
Author(s):  
A. S. Brun ◽  
A. Strugarek
Keyword(s):  
Magnetic Field ◽  
Recent Progress ◽  
Convection Zone ◽  
Thermal Structure ◽  
Solar Convection ◽  
Self Consistent ◽  
The Mean ◽  
The Magnetic Field

AbstractWe briefly present recent progress using the ASH code to model in 3-D the solar convection, dynamo and its coupling to the deep radiative interior. We show how the presence of a self-consistent tachocline influences greatly the organization of the magnetic field and modifies the thermal structure of the convection zone leading to realistic profiles of the mean flows as deduced by helioseismology.

scholarly journals Weak influence of near-surface layer on solar deep convection zone revealed by comprehensive simulation from base to surface

2019 ◽  
Vol 5 (1) ◽  
pp. eaau2307 ◽  
Author(s):  
H. Hotta ◽  
H. Iijima ◽  
K. Kusano
Keyword(s):  
Convection Zone ◽  
Solar Surface ◽  
Deep Convection ◽  
Surface Region ◽  
Local Domain ◽  
Near Surface ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Weak Influence ◽  
The Magnetic Field

The solar convection zone is filled with turbulent convection in highly stratified plasma. Several theoretical and observational studies suggest that the numerical calculations overestimate the convection velocity. Since all deep convection zone calculations exclude the solar surface due to substantial temporal and spatial scale separations, the solar surface, which drives the thermal convection with efficient radiative cooling, has been thought to be the key to solve this discrepancy. Thanks to the recent development in massive supercomputers, we are successful in performing the comprehensive calculation covering the whole solar convection zone. We compare the results with and without the solar surface in the local domain and without the surface in the full sphere. The calculations do not include the rotation and the magnetic field. The surface region has an unexpectedly weak influence on the deep convection zone. We find that just including the solar surface cannot solve the problem.

scholarly journals Simulating the Solar Dynamo

1993 ◽  
Vol 157 ◽  
pp. 111-121
Author(s):  
Axel Brandenburg
Keyword(s):  
Eddy Viscosity ◽  
Convection Zone ◽  
Transport Coefficients ◽  
Mean Field ◽  
Field Orientation ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Magnetic Diffusivity ◽  
The Magnetic Field

Mean-field and direct simulations of the hydrodynamics and hydromagnetics of the solar convection zone are discussed with the ultimate aim to understand the generation of differential rotation and magnetic fields. Various arguments constraining the values of the various turbulent diffusion coefficients are presented. It is suggested that the turbulent magnetic diffusivity is much smaller than the eddy viscosity which, in turn, is by up to a factor of ten smaller than the eddy conductivity. The magnetic field obtained from direct simulations is highly intermittent, and there is no clear systematic orientation of bipolar regions emerging from the convection zone. Various mechanisms that might cause such a field orientation are considered. Finally, the application of direct simulations to the determination of mean-field transport coefficients is emphasised.

scholarly journals Helicity transport from solar convection zone to interplanetary space

2012 ◽  
Vol 8 (S294) ◽  
pp. 505-518
Author(s):  
Mei Zhang
Keyword(s):  
Magnetic Field ◽  
Convection Zone ◽  
Interplanetary Space ◽  
Magnetic Helicity ◽  
Solar Photosphere ◽  
Solar Magnetic Fields ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Magnetic Flux Ropes ◽  
Solar Winds

AbstractMagnetic helicity is a physical quantity that describes field topology. It is also a conserved quantity as Berger in 1984 demonstrated that the total magnetic helicity is still conserved in the corona even when there is a fast magnetic reconnection. It is generally believed that solar magnetic fields, together with their helicity, are created in the convection zone by various dynamo processes. These fields and helicity are transported into the corona through solar photosphere and finally released into the interplanetary space via various processes such as coronal mass ejections (CMEs) and solar winds. Here I will give a brief review on our recent works, first on helicity observations on the photosphere and how to understand these observations via dynamo models. Mostly, I will talk about what are the possible consequences of magnetic helicity accumulation in the corona, namely, the formation of magnetic flux ropes, CMEs taking place as an unavoidable product of coronal evolution, and flux emergences as a trigger of CMEs. Finally, I will address on in what a form magnetic field in the interplanetary space would accommodate a large amount of magnetic helicity that solar dynamo processes have been continuously producing.

scholarly journals Helicity–vorticity turbulent pumping of magnetic fields in the solar dynamo

2012 ◽  
Vol 8 (S294) ◽  
pp. 367-368
Author(s):  
V. V. Pipin
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Differential Rotation ◽  
Large Scale ◽  
Convection Zone ◽  
Solar Dynamo ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Large Scale Magnetic Field ◽  
Convective Motions

AbstractThe interaction of helical convective motions and differential rotation in the solar convection zone results in turbulent drift of a large-scale magnetic field. We discuss the pumping mechanism and its impact on the solar dynamo.

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