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| Titel |
Magnetosheath Turbulence at MHD Scales: A Statistical Study |
| VerfasserIn |
Shiyong Huang, Fouad Sahraoui, Lina Hadid, Zhigang Yuan |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105371
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| Publikation (Nr.) |
 EGU/EGU2015-7893.pdf |
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| Zusammenfassung |
| Turbulence is ubiquitous in space plasmas, such as terrestrial magnetotail and magnetosheath,
solar wind, or the interstellar medium. In the solar wind, it is well established that at MHD
scales, the magnetic energy spectra generally follow the so-called Kolmogorov’s spectrum
f-5/3. In the magnetosheath, Alexandrova et al. [2006] observed a Kolmogorov-like inertial
range in the frequency range f < fci. In this study, we used three years data from the Cluster
mission to statistically investigate the existence of the Kolmogorov inertial range in the whole
magnetosheath, including flanks and subsolar regions. Statistical results show that most
spectra are shallower than the Kolmogorov one, and have a scaling ~ f-1recalling the energy
containing scales of solarwind turbulence. These spectra were found to be populated by
uncorrelated fluctuations. The Kolmogorov scaling is observed only away from the bock
shock and in the flanks region. These results suggest that random-like fluctuations are
generated behind the shock, which reach a fully developed turbulence state only after some
time corresponding to their propagation (or advection) away from the shock. At kinetic scales
no dependence of the turbulence scaling on the location in the magnetosheath was found. |
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