scholarly journals Finite element modeling of nonlinear dispersive field line resonances: Trapped shear Alfvén waves inside field-aligned density structures

2003 ◽  
Vol 108 (A11) ◽  
Author(s):  
J. Y. Lu
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Field Line ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Element Modeling ◽  
Field Line Resonances ◽  
Shear Alfven Waves

scholarly journals 3-D global hybrid simulations of magnetospheric response to foreshock processes

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Feng Shi ◽  
Yu Lin ◽  
Xueyi Wang ◽  
Boyi Wang ◽  
Yukitoshi Nishimura
Keyword(s):  
Solar Wind ◽  
Field Line ◽  
Mode Conversion ◽  
Wave Spectrum ◽  
Alfven Waves ◽  
Wide Frequency Range ◽  
Alfvén Waves ◽  
Wave Power ◽  
Field Line Resonances ◽  
Field Aligned Current

AbstractIt has been suggested that ion foreshock waves originating in the solar wind upstream of the quasi-parallel (Q-||) shock can impact the planetary magnetosphere leading to standing shear Alfvén waves, i.e., the field line resonances (FLRs). In this paper, we carry out simulations of interaction between the solar wind and terrestrial magnetosphere under radial interplanetary magnetic field conditions by using a 3-D global hybrid model, and show the properties of self-consistently generated field line resonances through direct mode conversion in magnetospheric response to the foreshock disturbances for the first time. The simulation results show that the foreshock disturbances from the Q-|| shock can excite magnetospheric ultralow-frequency waves, among which the toroidal Alfvén waves are examined. It is found that the foreshock wave spectrum covers a wide frequency range and matches the band of FLR harmonics after excluding the Doppler shift effects. The fundamental harmonic of field line resonances dominates and has the strongest wave power, and the higher the harmonic order, the weaker the corresponding wave power. The nodes and anti-nodes of the odd and even harmonics in the equatorial plane are also presented. In addition, as the local Alfvén speed increases earthward, the corresponding frequency of each harmonic increases. The field-aligned current in the cusp region indicative of the possibly observable aurora is found to be a result of magnetopause perturbation which is caused by the foreshock disturbances, and a global view substantiating this scenario is given. Finally, it is found that when the solar wind Mach number decreases, the strength of both field line resonance and field-aligned current decreases accordingly.

Exact First Order Finite Element Modeling for Eddy Current NDE

1991 ◽  
Vol 3 (1) ◽  
pp. 235-253 ◽  
Author(s):  
L. D. Philipp ◽  
Q. H. Nguyen ◽  
D. D. Derkacht ◽  
D. J. Lynch ◽  
A. Mahmood
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Eddy Current ◽  
Element Modeling ◽  
First Order ◽  
Eddy Current Nde
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