Spectral scaling in the turbulent Earth's plasma sheet revisited

Z. Vörös (1, 2) , W. Baumjohann (1) , R. Nakamura (1) , A. Runov (1) , M. Volwerk (1, 3) , Y. Asano (4) , D. Jankovicová (2) , E. A. Lucek (5) , H. Rème (6)

1 IWF - Space Research Institute of Austrian Academy of Sciences
2 IAP - Institute of Atmospheric Physics [Prague]
3 MPE - Max-Planck-Institut für Extraterrestrische Physik
4 TITECH - Tokyo Institute of Technology [Tokyo]
5 Imperial College London
6 CESR - Centre d'étude spatiale des rayonnements

Bursty bulk flow associated magnetic fluctuations exhibit at least three spectral scaling ranges in the Earth's plasma sheet. Two of the three scaling ranges can be associated with multi-scale magnetohydrodynamic turbulence between the spatial scales from ~100 km to several R_E (R_E is the Earth's radius). These scales include the inertial range and below ~0.5 R_E a steepened scaling range, theoretically not fully understood yet. It is shown that, in the near-Earth plasma sheet, the inertial range can be robustly identified only if multi-scale quasi stationary (MSQS) data intervals are selected. Multiple bursty flow associated magnetic fluctuations, however, exhibit 1/f type scaling indicating that large-scale fluctuations are controlled by multiple uncorrelated driving sources of the bulk flows (e.g. magnetic reconnection, instabilities).

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]; Sciences de la Terre

Z. Vörös, W. Baumjohann, R. Nakamura, A. Runov, M. Volwerk, et al.. Spectral scaling in the turbulent Earth's plasma sheet revisited. Nonlinear Processes in Geophysics, 2007, 14 (4), pp.535-541. ⟨hal-00331104⟩