Flux-tube divergence, coronal heating, and the solar wind

1993 ◽  
Vol 410 ◽  
pp. L123 ◽  
Author(s):  
Y.-M. Wang
Keyword(s):  
Solar Wind ◽  
Flux Tube ◽  
Coronal Heating

Solar wind speed and coronal flux-tube expansion

1990 ◽  
Vol 355 ◽  
pp. 726 ◽  
Author(s):  
Y.-M. Wang ◽  
N. R., Jr. Sheeley
Keyword(s):  
Solar Wind ◽  
Wind Speed ◽  
Flux Tube ◽  
Solar Wind Speed ◽  
Tube Expansion

scholarly journals A Multiple Flux-tube Solar Wind Model

2017 ◽  
Vol 838 (2) ◽  
pp. 89 ◽  
Author(s):  
Rui F. Pinto ◽  
Alexis P. Rouillard
Keyword(s):  
Solar Wind ◽  
Flux Tube ◽  
Wind Model ◽  
Solar Wind Model

scholarly journals Numerical Study of Divergence Cleaning and Coronal Heating/Acceleration Methods in the 3D COIN-TVD MHD Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Chang Liu ◽  
Fang Shen ◽  
Yousheng Liu ◽  
Man Zhang ◽  
Xiaojing Liu
Keyword(s):  
Solar Wind ◽  
Numerical Study ◽  
Three Dimensional ◽  
Coronal Heating ◽  
Solar Wind Structure ◽  
Wind Simulation ◽  
Simulation Results ◽  
Mhd Model ◽  
Cleaning Methods ◽  
Powell Method

In the solar coronal numerical simulation, the coronal heating/acceleration and the magnetic divergence cleaning techniques are very important. The coronal–interplanetary total variation diminishing (COIN-TVD) magnetohydrodynamic (MHD) model is developed in recent years that can effectively realize the coronal–interplanetary three-dimensional (3D) solar wind simulation. In this study, we focus on the 3D coronal solar wind simulation by using the COIN-TVD MHD model. In order to simulate the heating and acceleration of solar wind in the coronal region, the volume heating term in the model is improved efficiently. Then, the influence of the different methods to reduce the ∇⋅B constraint error on the coronal solar wind structure is discussed. Here, we choose Carrington Rotation (CR) 2199 as a study case and try to make a comparison of the simulation results among the different magnetic divergence cleaning methods, including the diffusive method, the Powell method, and the composite diffusive/Powell method, by using the 3D COIN-TVD MHD model. Our simulation results show that with the different magnetic divergence cleaning methods, the ∇⋅B error can be reduced in different levels during the solar wind simulation. Among the three divergence cleaning methods we used, the composite diffusive/Powell method can maintain the divergence cleaning constraint better to a certain extent, and the relative magnetic field divergence error can be controlled in the order of 10−9. Although these numerical simulations are performed for the background solar corona, these methods are also suitable for the simulation of CME initiation and propagation.

scholarly journals Coronal heating and wind acceleration by nonlinear Alfvén waves – global simulations with gravity, radiation, and conduction

2008 ◽  
Vol 15 (2) ◽  
pp. 295-304 ◽  
Author(s):  
T. K. Suzuki
Keyword(s):  
Solar Wind ◽  
Alfven Waves ◽  
Coronal Heating ◽  
Alfvén Waves ◽  
Flux Tubes ◽  
Giant Stars ◽  
Solar Winds ◽  
Dynamical Simulations ◽  
Consistent Manner ◽  
Red Giant

Abstract. We review our recent results of global one-dimensional (1-D) MHD simulations for the acceleration of solar and stellar winds. We impose transverse photospheric motions corresponding to the granulations, which generate outgoing Alfvén waves. We treat the propagation and dissipation of the Alfvén waves and consequent heating from the photosphere by dynamical simulations in a self-consistent manner. Nonlinear dissipation of Alfven waves becomes quite effective owing to the stratification of the atmosphere (the outward decrease of the density). We show that the coronal heating and the solar wind acceleration in the open magnetic field regions are natural consequence of the footpoint fluctuations of the magnetic fields at the surface (photosphere). We find that the properties of the solar wind sensitively depend on the fluctuation amplitudes at the solar surface because of the nonlinearity of the Alfvén waves, and that the wind speed at 1 AU is mainly controlled by the field strength and geometry of flux tubes. Based on these results, we point out that both fast and slow solar winds can be explained by the dissipation of nonlinear Alfvén waves in a unified manner. We also discuss winds from red giant stars driven by Alfvén waves, focusing on different aspects from the solar wind.

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