Wave-number spectra and intermittency in the terrestrial foreshock region
- Abstract
Wave-number spectra of magnetic field fluctuations are directly determined in the terrestrial foreshock region (upstream of a quasiparallel collisionless shock wave) using four-point Cluster spacecraft measurements. The spectral curve is characterized by three ranges reminiscent of turbulence: energy injection, inertial, and dissipation range. The spectral index for the inertial range spectrum is close to Kolmogorov’s slope, -5/3. On the other hand, the fluctuations are highly anisotropic and intermittent perpendicular to the mean magnetic field direction. These results suggest that the foreshock is in a weakly turbulent and intermittent state in which parallel propagating Alfvén waves interact with one another, resulting in the phase coherence or the intermittency.
- BibTeX
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@article{id909, author = {Narita, Y. and Glassmeier, K. and Treumann, R.}, journal = {Physical Review Letters}, language = {en}, number = {19}, title = {Wave-number spectra and intermittency in the terrestrial foreshock region}, volume = {79}, year = {2006}, }
- EndNote
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%O Journal Article %A Narita, Y. %A Glassmeier, K. %A Treumann, R. %J Physical Review Letters %G en %N 19 %T Wave-number spectra and intermittency in the terrestrial foreshock region %V 79 %D 2006