Abstract
Large amplitude MHD waves are commonly found in the solar wind. Nonlinear interactions between the MHD waves are likely to produce finite correlation among the wave phases. For discussions of various transport processes of energetic particles, it is fundamentally important to determine whether the wave phases are randomly distributed (as assumed in quasi-linear theories) or they have a finite coherence. Using a method based on a surrogate data technique and a fractal analysis, we analyzed Geotail magnetic field data (provided by S. Kokubun and T. Nagai through DARTS at the Institute of Space and Astronautical Science) to evaluate the phase coherence among the MHD waves in the earth's foreshock region. The correlation of wave phases does exist, indicating that the nonlinear interactions between the waves is in progress.
Similar content being viewed by others
References
Hada, T., Kennel, C. F. and Terasawa, T.: 1987, ‘Excitation of Compressional Waves and the Formations of Shocklets in the Earth's Foreshock’, J.Geophys.Res. 92, 4423-4435.
Higuchi, T.: 1988, ‘Approach to an Irregular Time Series on the Basis of the Fractal’, Physica D 31, 277-283.
Hoppe, M. M., Russell, C. T., Frank, L. A., Eastman, T. E. and Greenstadt, E. W.: 1981, ‘Upstream Hydromagnetic-waves and their Association with Backstreaming Ion Populations-ISEE-1 and ISEE-2 Observations’, J.Geophys.Res. 86, 4471-4492.
Kuramitsu, Y. and Hada, T.: 2000, ‘Acceleration of Charged Particles by Large Amplitude MHD Waves: Effect of Wave Spatial Correlation’, Geophys.Res.Lett. 27, 629-632.
Schwartz, S. J. and Burgess, D.: 1991, ‘Quasi-parallel Shocks-A Patchwork of 3-dimensional Structures’, Geophys.Res.Lett. 18, 373-376.
de Wit, T. D., Krasnosel'skikh, V. V., Dunlop, T. and Luhr, H.: 1999, ‘Identifying Nonlinear Wave Interactions in Plasmas Using Two-point Measurements: A Case Study of Short Large Amplitude Magnetic Structures’, J.Geophys.Res. 104, 17079-17090.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hada, T., Koga, D. & Yamamoto, E. Phase coherence of MHD waves in the solar wind. Space Science Reviews 107, 463–466 (2003). https://doi.org/10.1023/A:1025506124402
Issue Date:
DOI: https://doi.org/10.1023/A:1025506124402