Heating of the solar corona by Alfvén waves: magnetohydrodynamic calculation of the height temperature profile of the transition region

2019 ◽  
Vol 55 (3) ◽  
pp. 295-318
Keyword(s):  
Solar Corona ◽  
Temperature Profile ◽  
Transition Region ◽  
Alfven Waves ◽  
Alfvén Waves

scholarly journals Magnetohydrodynamic calculation of the temperature and wind velocity profile of the solar transition region. Preliminary results.

2018 ◽  
Vol 145 ◽  
pp. 03009 ◽  
Author(s):  
Todor M. Mishonov ◽  
Albert M. Varonov ◽  
Nedeltcho I. Zahariev ◽  
Rositsa V. Topchiyska ◽  
Boian V. Lazov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Spectral Density ◽  
Solar Corona ◽  
Temperature Profile ◽  
Transition Region ◽  
Wind Velocity ◽  
Spectral Lines ◽  
Mhd Waves ◽  
Dimensional Approximation ◽  
Height Dependence

The sharp almost step like increase the temperature in the transition region (TR) between chromosphere and solar corona is well-known from decades; for first time we are giving a detailed magnetohydrodynamic (MHD) calculation of the height dependence of the temperature. The width of the transition region is evaluated by maximal value of the logarithmic derivative of the temperature. At fixed heating, only MHD can give such a narrow width and in such sense, even the qualitative agreement with the observational data, gives the final verdict what the heating mechanism of the solar corona is. Static profiles of the temperature and wind velocity are calculated for static frequency dependent spectral density of the incoming MHD waves; no time dependent computer simulations. At fixed spectral density of MHD waves, the MHD calculation predicts height dependence of the non-thermal broadening of spectral lines and its angular dependence. For illustration is used one dimensional approximation of completely ionized hydrogen plasma in weak magnetic field, but it is considered that the width of the TR is weakly dependent with respect of further elaboration. The analyzed MHD calculation is a numerical confirmation of the qualitative concept of self-induced opacity of the plasma with respect to MHD waves. The plasma viscosity strongly increases with the temperature. Heated by MHD waves, plasma increases the wave absorption and this positive feedback leads to further heating. The static temperature profile is a result of a self-consistent calculation of propagation of MHD wave through the static background of wind and temperature profile. The numerical method allows consideration of incoming MHD waves with an arbitrary spectral density. Further elaboration of the method are briefly discussed: influence of second viscosity in the chromospheric part of the TR, influence of the magnetic field on the coronal side of the TR and investigation of such type effects on the width of the TR.

Generation of harmonic Alfvén waves and its implications to heavy ion heating in the solar corona: Hybrid simulations

2020 ◽  
Vol 27 (1) ◽  
pp. 012901
Author(s):  
Jiansheng Yao ◽  
Quanming Lu ◽  
Xinliang Gao ◽  
Jian Zheng ◽  
Huayue Chen ◽  
...  
Keyword(s):  
Solar Corona ◽  
Heavy Ion ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Ion Heating ◽  
Hybrid Simulations

NONLINEAR DAMPING OF ALFVÉN WAVES IN THE SOLAR CORONA BELOW 1.5 SOLAR RADII

2015 ◽  
Vol 811 (2) ◽  
pp. 88 ◽  
Author(s):  
J. S. Zhao ◽  
Y. Voitenko ◽  
Y. Guo ◽  
J. T. Su ◽  
D. J. Wu
Keyword(s):  
Solar Corona ◽  
Nonlinear Damping ◽  
Alfven Waves ◽  
Alfvén Waves

The problem of phase mixed shear Alfvén waves in the solar corona revisited

2008 ◽  
Vol 329 (8) ◽  
pp. 780-785 ◽  
Author(s):  
G. Mocanu ◽  
A. Marcu ◽  
I. Ballai ◽  
B. Orza
Keyword(s):  
Solar Corona ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Shear Alfven Waves

Landau damped kinetic Alfvén waves and coronal heating

2009 ◽  
Vol 76 (2) ◽  
pp. 239-246 ◽  
Author(s):  
R. P. SHARMA ◽  
SACHIN KUMAR
Keyword(s):  
Solar Corona ◽  
Initial Conditions ◽  
Planck Equation ◽  
Alfven Waves ◽  
Coronal Heating ◽  
Landau Damping ◽  
Alfvén Waves ◽  
Energetic Electrons ◽  
Turbulent Spectra ◽  
Kinetic Alfvén Waves

AbstractSome recent observations of solar corona suggest that the kinetic Alfvén waves (KAWs) turbulence may be responsible for electron acceleration in solar corona and coronal heating. In the present research, we investigate the turbulent spectra of KAW due to filamentation process in the presence of Landau damping and particle energization. We present here the numerical simulation of model equation governing the nonlinear dynamics of the KAW in the presence of Landau damping. When the ponderomotive and Joule heating nonlinearities are incorporated in the KAW dynamics, the power spectra of the turbulent field is evaluated and used for particle heating. Our results reveal the formation of damped coherent magnetic filamentary structures and the turbulent spectra. The effect of Landau damping is to make the turbulent spectra steeper. Two types of scalings k−3.6 and k−4 have been obtained. We have studied the turbulence with different initial conditions. Using the Fokker–Planck equation with the new velocity space diffusion coefficient, we find the distribution function of energetic electrons in these turbulent structures. Landau damped KAWs may be responsible for the acceleration of the energetic electrons in solar corona and coronal heating.

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