Earth Planets Space, Vol. 58 (No. 11), pp. e53-e56, 2006E-LETTER
Yuto Katoh1 and Masahide Iizima2
1Planetary Plasma and Atmospheric Research Center, Graduate School of Science, Tohoku University, Sendai, Japan
2Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan
(Received June 26, 2006; Revised August 28, 2006; Accepted September 1, 2006; Online published November 15, 2006)
The mode conversion process from slow X-mode waves to fast X-mode waves by the tunneling effect has been studied by means of computer simulation. On the basis of the new approach by the simulation, we have confirmed that the mode conversion to the fast X-mode waves is especially effective in the case where the width of the evanescent layer which exists between the local UHR frequency and the local fast X-mode cut-off frequency, is of the order of the wave length of the incident slow X-mode waves. In space plasmas, this type of mode conversion process becomes important for the case where the different plasmas form a sharp boundary or a discontinuity at their contact boundary with a scale size of the order of the wave length of the incident slow X-mode waves.
Key words: Mode conversion, numerical experiment.