EGU21-14329, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Power Anisotropy, Dispersion Signature and Diffusion Region in the 3D Wavenumber Domain of Space Plasma Turbulence

Rong Lin1, Jiansen He1, Xingyu Zhu1, Lei Zhang2, Die Duan1, Fouad Sahraoui3, and Daniel Verscharen4,5
Rong Lin et al.
  • 1School of Earth and Space Sciences, Peking University Beijing, 100871, China
  • 2Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing, 100094, China
  • 3LPP, CNRS, Ecole Polytechnique, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, Sorbonne Université, PSL Research University, 91128 Palaiseau, France
  • 4Mullard Space Science Laboratory, University College London, Dorking RH5 6NT, UK
  • 5Space Science Center, University of New Hampshire, Durham NH 03824, USA

We explore the multi-faceted important features of turbulence (e.g., anisotropy, dispersion, diffusion) in the three-dimensional (3D) wavenumber domain (k, kperp1, kperp2), by employing the k-filtering technique to the high-quality measurements of fields and plasmas from multi-spacecraft constellation (i.e., MMS). We compute the 3D power spectral densities (PSDs) of magnetic and electric fluctuations (marked as PSD(δB(k)) and PSD(δE′‹vi›(k))), both of which show prominent spectral anisotropy in the sub-ion range. We calculate the ratio between PSD(δE′‹vi›(k)) and PSD(δB(k)), the distribution of which is related with nonlinear dispersion relation. We also compute the ratio between electric spectra in different frames of ion flow, that is PSD(δE′local vi)/PSD(δE′‹vi›), to demonstrate the turbulence ion diffusion region (T- IDR) in the wavenumber space. The T-IDR has an anisotropy and a preferential direction of wavevectors, which is generally consistent with the plasma wave theory prediction based on the dominance of kinetic Alfvén wave (KAW). This work manifests the worth of the k-filtering technique in diagnosing turbulence comprehensively, especially when the electric field is involved.

How to cite: Lin, R., He, J., Zhu, X., Zhang, L., Duan, D., Sahraoui, F., and Verscharen, D.: Power Anisotropy, Dispersion Signature and Diffusion Region in the 3D Wavenumber Domain of Space Plasma Turbulence, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14329,, 2021.

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