Observations of Magnetohydrodynamic Oscillations in the Solar Atmosphere with Properties of Alfven Waves

1996 ◽  
Vol 465 ◽  
pp. 436 ◽  
Author(s):  
Roger K. Ulrich
Keyword(s):  
Solar Atmosphere ◽  
Alfven Waves ◽  
Alfvén Waves

Estimation of the Energy Flux of Torsional Alfvén Waves in the Lower Solar Atmosphere Based on Measurements of the Doppler Velocities

2021 ◽  
Vol 61 (7) ◽  
pp. 1035-1037
Author(s):  
Yu. T. Tsap ◽  
A. V. Stepanov ◽  
Yu. G. Kopylova ◽  
O. V. Khaneychuk ◽  
T. B. Goldvarg
Keyword(s):  
Solar Atmosphere ◽  
Energy Flux ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Lower Solar Atmosphere

scholarly journals Numerical simulations of the lower solar atmosphere heating by two-fluid nonlinear Alfvén waves

2020 ◽  
Vol 639 ◽  
pp. A45
Author(s):  
B. Kuźma ◽  
D. Wójcik ◽  
K. Murawski ◽  
D. Yuan ◽  
S. Poedts
Keyword(s):  
Magnetic Flux ◽  
Numerical Simulations ◽  
Solar Atmosphere ◽  
Flux Tube ◽  
Alfven Waves ◽  
Alfven Wave ◽  
Magnetic Flux Tube ◽  
Alfvén Waves ◽  
Two Fluid ◽  
Lower Solar Atmosphere

Context. We present new insight into the long-standing problem of plasma heating in the lower solar atmosphere in terms of collisional dissipation caused by two-fluid Alfvén waves. Aims. Using numerical simulations, we study Alfvén wave propagation and dissipation in a magnetic flux tube and their heating effect. Methods. We set up 2.5-dimensional numerical simulations with a semi-empirical model of a stratified solar atmosphere and a force-free magnetic field mimicking a magnetic flux tube. We consider a partially ionized plasma consisting of ion + electron and neutral fluids, which are coupled by ion-neutral collisions. Results. We find that Alfvén waves, which are directly generated by a monochromatic driver at the bottom of the photosphere, experience strong damping. Low-amplitude waves do not thermalize sufficient wave energy to heat the solar atmospheric plasma. However, Alfvén waves with amplitudes greater than 0.1 km s−1 drive through ponderomotive force magneto-acoustic waves in higher atmospheric layers. These waves are damped by ion-neutral collisions, and the thermal energy released in this process leads to heating of the upper photosphere and the chromosphere. Conclusions. We infer that, as a result of ion-neutral collisions, the energy carried initially by Alfvén waves is thermalized in the upper photosphere and the chromosphere, and the corresponding heating rate is large enough to compensate radiative and thermal-conduction energy losses therein.

Are There Alfven Waves in the Solar Atmosphere?

Science ◽  
2007 ◽  
Vol 318 (5856) ◽  
pp. 1572-1574 ◽  
Author(s):  
R. Erdelyi ◽  
V. Fedun
Keyword(s):  
Solar Atmosphere ◽  
Alfven Waves ◽  
Alfvén Waves

scholarly journals Alfven Waves in the Lower Solar Atmosphere

Science ◽  
2009 ◽  
Vol 323 (5921) ◽  
pp. 1582-1585 ◽  
Author(s):  
D. B. Jess ◽  
M. Mathioudakis ◽  
R. Erdelyi ◽  
P. J. Crockett ◽  
F. P. Keenan ◽  
...  
Keyword(s):  
Solar Atmosphere ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Lower Solar Atmosphere

Characteristics of the Energy Transfer by Alfvén Waves in the Solar Atmosphere

2020 ◽  
Vol 60 (4) ◽  
pp. 446-451
Author(s):  
Yu. T. Tsap ◽  
A. V. Stepanov ◽  
Yu. G. Kopylova ◽  
O. V. Khaneichuk
Keyword(s):  
Energy Transfer ◽  
Solar Atmosphere ◽  
Alfven Waves ◽  
Alfvén Waves

scholarly journals Reflection and dissipation of oblique Alfvén waves in an isothermal atmosphere

1999 ◽  
Vol 22 (1) ◽  
pp. 161-169 ◽  
Author(s):  
Hadi Yahya Alkahby ◽  
M. A. Mahrous
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Transition Region ◽  
Solar Atmosphere ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Heating Mechanism ◽  
Downward Propagation ◽  
Isothermal Atmosphere ◽  
The Magnetic Field

In this article, we investigate the combined effects of viscosity and Ohmic electrical conductivity on upward and downward propagation oblique Alfvén waves in an isothermal atmosphere. It is shown that the presence and direction of the magnetic field play an important role in the structure and the heating mechanism of solar atmosphere. In addition, the atmosphere can be divided into two distinct regions connected by a transition region. In the lower region, the solution can be written as a linear combination of an upward and a downward propagation wave with unequal wavelengths. In the upper region, the solution decays exponentially with the altitude. Moreover, the magnetic field creates a reflecting and a non-absorbing transition region. On the contrary, the viscosity and Ohmic electrical conductivity produce a reflecting and an absorbing transition region. The nature of the transition region depends on the relative strength of the viscous diffusivity with respect to the resistive diffusivity and on the direction of the magnetic field. A unique solution is determined. The reflection coefficient and damping factors are derived and the conclusions are discussed in connection with the nature of the heating mechanism of the solar atmosphere.

scholarly journals Alfvén Waves in the Solar Atmosphere

2012 ◽  
Vol 175 (1-4) ◽  
pp. 1-27 ◽  
Author(s):  
M. Mathioudakis ◽  
D. B. Jess ◽  
R. Erdélyi
Keyword(s):  
Solar Atmosphere ◽  
Alfven Waves ◽  
Alfvén Waves
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