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study of interaction between acoustic-alfven waves in solar magnetic flux tubes
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نویسنده
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fazel z
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منبع
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پژوهش فيزيك ايران - 1400 - دوره : 21 - شماره : 3 - صفحه:93 -98
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چکیده
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Solar acoustic oscillations are actually the same 5 minute oscillations that appear in the photosphere. these oscillations appear to be unable to penetrate into the solar corona due to the acoustic cut off of stratified atmosphere and the sharp temperature gradient in the transition region. the 5 minute acoustic oscillations may resonantly convert into alfven waves in theß~~1 region of the solar atmosphere. by perturbing the equilibrium state of the magnetised plasma, we showed that the acoustic and alfven waves can interact through the nonlinear terms of the ideal mhd equations. we found that alfven waves with twice the period of acoustic waves may propagate to upper layers when the speeds of sound and alfven waves are equal, cs ~~ va . this condition is obtained when ϖ=1/2ϖs.
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کلیدواژه
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solar magnetic flux tubes ,alfven waves ,acoustic oscillations ,resonant conversion
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آدرس
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university of tabriz, physics faculty, astrophysics department, iran
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پست الکترونیکی
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z_fazel@tabrizu.ac.ir
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Study of interaction between acoustic-Alfven waves in solar magnetic flux tubes
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Authors
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Fazel Z
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Abstract
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Solar acoustic oscillations are actually the same 5 minute oscillations that appear in the photosphere. These oscillations appear to be unable to penetrate into the solar corona due to the acoustic cut off of stratified atmosphere and the sharp temperature gradient in thetransition region. The 5 minute acoustic oscillations may resonantly convert into Alfven waves in theß~~1 region of the solar atmosphere. By perturbing the equilibrium state of the magnetised plasma, we showed that the acoustic and Alfven waves can interact through the nonlinear terms of the ideal MHD equations. We found that Alfven waves with twice the period of acousticwaves may propagate to upper layers when the speeds of sound and Alfven waves are equal, cs ~~ vA . This condition is obtained when, ϖ=1/2ϖs.
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Keywords
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solar magnetic flux tubes ,Alfven waves ,acoustic oscillations ,resonant conversion
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