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Wavelet analysis of magnetic turbulence in the Earth's plasma sheet

W. Baumjohann·R. Nakamura·A. Runov·M. Volwerk·T. L. Zhang·A. Balogh
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Abstract

Recent studies provide evidence for the multi-scale nature of magnetic turbulence in the plasma sheet. Wavelet methods represent modern time series analysis techniques suitable for the description of statistical characteristics of multi-scale turbulence. Cluster FGM (fluxgate magnetometer) magnetic field high-resolution (~67 Hz) measurements are studied during an interval in which the spacecraft are in the plasma sheet. As Cluster passes through different plasma regions, physical processes exhibit non-steady properties on magnetohydrodynamic (MHD) and small, possibly kinetic scales. As a consequence, the implementation of wavelet-based techniques becomes complicated due to the statistically transitory properties of magnetic fluctuations and finite size effects. Using a supervised multi-scale technique which allows existence test of moments, the robustness of higher-order statistics is investigated. On this basis the properties of magnetic turbulence are investigated for changing thickness of the plasma sheet.

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W. Baumjohann, R. Nakamura, A. Runov, M. Volwerk, T. L. Zhang, A. Balogh. 2004-10-21. Wavelet analysis of magnetic turbulence in the Earth's plasma sheet. https://doi.org/10.1063/1.1667499

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