冕环中扭转Alfv&amp;#233;n波和快波的耦合共振

	冕环中扭转Alfv&#233;n波和快波的耦合共振
	叶占银 ; 魏奉思 ; 王赤 ; 冯学尚 ; 罗庆宇
刊名	空间科学学报
	2004
卷号	24 期号:6 页码:401-411
关键词	角频率近似间断耗散数系共振耦合波幅扭转位置
ISSN号	0254-6124
其他题名	ALFVEN WAVE AND FAST WAVE COUPLING RESONANCE IN CORONAL LOOPS
通讯作者	北京8701信箱
中文摘要	推广完备正交函数系(OFSE)展开方法,应用它研究冕环中无耗散扭转Alfvén波和快波耦合的时变过程.采用这种方法,从数学上描述了总体波模的固有角频率,从理论和数值计算结果两方面分析了Alfvén波和快波耦合时冕环中磁力线Alfvén波固有角频率.采用这种方法,分析了耦合驱动项和Alfvén波共振的关系．计算结果给出了耦合共振出现位置Alfvén波和快波的波幅特征,发现如果足点驱动角频率不等于冕环总体波模的固有角频率,在耦合共振位置当扭转Alfvén波幅出现δ断面时,怏波振幅沿径向梯度很大,有时近似为一个间断,非常有利于快波耗散;如果足点驱动角频率等于总体波模的固有角频率,Alfvén波振幅出现δ断面时在径向出现丰富的小尺度结构,共振位置近似为一个间断,非常有利于Alfvén波耗散．
英文摘要	Complete Orthogonal Function Series Expansion (OFSE} method is generalized and applied to make research about the time evolution coupling process of fast and Alfven waves in coronal loops.With the OFSE method, intrinsic angular frequencies of coronal loop quasi-modes could be described mathematically and the intrinsic angular frequency of torsional Alfven waves in every magnetic field line of coronal loops is investigated theoretically and numerically.With the method, the relationship between a coupling driven term and torsional Alfven wave resonance is analyzed.Numerical result presents wave amplitude features at the coupling resonant place. It is found that: when the footpoint driven angular frequency is not equal to one of quasi-mode intrinsic angular frequencies, at the resonant position with a b profile of Alfven wave amplitude,absolute value of radial gradient of fast wave amplitude is very large and approximates a discontinuity, which is necessary to dissipate fast waves. On the other hand, if the footpoint driven angular frequency is equal to one of quasi-mode intrinsic angular frequencies, widespread small scale structure of Alfven wave amplitude and an approximate discontinuity at resonant place,which are necessary to dissipate Alfven waves,appear.
学科主题	空间物理
资助信息	国家自然科学基金资助项目
语种	中文
内容类型	期刊论文
源URL	[http://ir.cssar.ac.cn/handle/122/1404]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	叶占银,魏奉思,王赤,等. 冕环中扭转Alfv&#233;n波和快波的耦合共振[J]. 空间科学学报,2004,24(6):401-411.
APA	叶占银,魏奉思,王赤,冯学尚,&罗庆宇.(2004).冕环中扭转Alfvén波和快波的耦合共振.空间科学学报,24(6),401-411.
MLA	叶占银,et al."冕环中扭转Alfvén波和快波的耦合共振".空间科学学报 24.6(2004):401-411.