Frequency dependence of resonant absorption and over-reflection of magnetosonic waves in nonuniform structures with shear mass flow

被引:0
|
作者
Csik, AT
Cadez, VM
Goossens, M
机构
[1] Katholieke Univ Leuven, Ctr Plasma Astrophys, B-3001 Heverlee, Belgium
[2] State Univ Ghent, Sterrenkunding Observ, B-9000 Ghent, Belgium
关键词
magnetohydrodynamics (MHD); methods : numerical; Sun : corona; Sun : oscillations;
D O I
暂无
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Processes of resonant absorption and over-reflection of magnetosonic modes may occur in nonuniform plasmas with a shear mass flow along the magnetic field. In this work, we study how these two phenomena depend on the frequency omega of waves propagating in a given direction prescribed by polar angles theta and phi of wave vector k. Plasma is assumed nonuniform within a transitional layer that separates two semi-infinite uniform regions. The considered wave propagates only in one of the two regions and is reflected from the nonuniform transitional layer either totally or partially depending on the efficiency of resonant processes. The resonant absorption and over-reflection are strongly dependent on wave frequency for both the slow and fast magnetosonic mode as shown in corresponding figures. Under conditions relevant to the solar atmosphere, we found that typical MHD waves with periods from few seconds up to much larger values of several minutes and more, can be resonantly absorbed and also over-reflected. This important fact has to be taken into account in making models of energy transports in the corona.
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页码:1090 / 1096
页数:7
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