Generation of acoustic waves by harmonic electric current sheets in the sea

1981 ◽  
Vol 69 (4) ◽  
pp. 970-973
Author(s):  
K. J. Harker ◽  
A. C. Fraser–Smith
Keyword(s):  
Electric Current ◽  
Acoustic Waves ◽  
Current Sheets

The energy of electric current sheets

Solar Physics ◽  
1982 ◽  
Vol 81 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Y. Q. Hu ◽  
B. C. Low
Keyword(s):  
Electric Current ◽  
Current Sheets

The stability of electric current sheets

1990 ◽  
Vol 14 (2) ◽  
pp. 180-190 ◽  
Author(s):  
Zheng Hui-nan ◽  
Hu You-qiu
Keyword(s):  
Electric Current ◽  
Current Sheets ◽  
The Stability

The energy of electric current sheets

Solar Physics ◽  
1983 ◽  
Vol 84 (1-2) ◽  
pp. 83-98 ◽  
Author(s):  
B. C. Low ◽  
Y. Q. Hu
Keyword(s):  
Electric Current ◽  
Current Sheets

Evolution of current sheets following the onset of enhanced resistivity

1982 ◽  
Vol 27 (1) ◽  
pp. 157-176 ◽  
Author(s):  
T. G. Forbes ◽  
E. R. Priest ◽  
A. W. Hood
Keyword(s):  
Current Sheet ◽  
Acoustic Waves ◽  
Wave Speed ◽  
Mhd Equations ◽  
Fast Mode ◽  
Current Sheets ◽  
Flow Speeds ◽  
Sheet Width ◽  
Flux Model ◽  
A Current

An important aspect of pre-flare current sheets in the solar atmosphere is the sudden enhancement of the effective electrical resistivity in the sheet due to the onset of a plasma micro-instability. Numerical and analytical solutions to the isothermal MHD equations are here presented that describe the evolution of a current sheet subsequent to such an enhancement in the resistivity. The solutions show that, if the initial width of the current sheet is less than the acoustic-diffusion length obtained by dividing the resistivity by the sound speed, then isomagnetic shocks are formed. These shocks propagate outward from the the centre of the current sheet and are transformed into fast-mode magneto-acoustic waves when they reach the edges of the current sheet. The fast-mode waves thus formed continue to propagate outward beyond the confines of the current sheet. In contrast to a previous study by Cheng, the present solutions demonstrate that flow speeds several times greater than the local fast-mode wave speed can be produced if the plasma beta parameter and the initial sheet width are sufficiently small. The results may be relevant to the triggering of a solar flare, as in the emerging flux model of flares.

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