EGU21-15525
https://doi.org/10.5194/egusphere-egu21-15525
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Sounding plasma turbulence at sub-ion scales with Fast Iterative Filtering in space and time.

Emanuele Papini1,2, Antonio Cicone3, Luca Franci2,4, Mirko Piersanti5, Simone Landi1,2, Andrea Verdini1,2, and Petr Hellinger6
Emanuele Papini et al.
  • 1Dipartimento di Fisica e Astronomia, Università degli studi di Firenze, Sesto Fiorentino, Italy (emanuele.papini@unifi.it))
  • 2INAF, Osservatorio Astrofisico di Arcetri, Firenze, Italy
  • 3Dipartimento di Ingegneria e Scienze dell'Informazione e Matematica, Università dell'Aquila, L'Aquila, Italy
  • 4School of Physics and Astronomy, Queen Mary University of London, London, United Kingdom
  • 5INFN, Sezione di Roma Tor Vergata, Roma, Italy
  • 6Astronomical Institute, CAS, Prague, Czech Republic

We present the results from a spacetime study of Hall-MHD and Hybrid-kinetic numerical simulations of decaying turbulence. By combining Fourier analysis and Multivariate Iterative Filtering (a new technique developed for the analysis of nonstationary nonlinear signals) we calculate the kω-power spectrum of magnetic, velocity, and density fluctuations at the maximum of turbulent activity. Results show that the magnetic power spectrum at sub-ion scales is formed by localized structures and/or perturbations with temporal frequencies much smaller than the ion-cyclotron frequency Ωi. Going toward smaller ion-kinetic scales, the contribution of low-medium frequency perturbations (ω < 3Ωi) to the magnetic spectrum becomes important. Our analysis clearly indicates that such low-frequency perturbations have no kinetic-Alfvén neither Ion-cyclotron origin. At higher frequencies, we clearly identify signatures of both whistler and kinetic-Alfvén wave activity. However, their energetic contribution to the turbulent cascade is negligible. We conclude that the dynamics of turbulence at sub-ion scales is mainly shaped by localized intermittent structures, with no contribution of wavelike perturbations.

How to cite: Papini, E., Cicone, A., Franci, L., Piersanti, M., Landi, S., Verdini, A., and Hellinger, P.: Sounding plasma turbulence at sub-ion scales with Fast Iterative Filtering in space and time., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15525, https://doi.org/10.5194/egusphere-egu21-15525, 2021.

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