Spatiotemporal properties of two-dimensional (2D) Hall-magnetohydrodynamic (MHD) turbulence at intermediate plasma β = 2 are studied by means of Fast Iterative Filtering (FIF), a new technique for the decomposition of nonstationary nonlinear signals. Results show that the magnetic energy at sub-ion scales is concentrated in perturbations with frequencies smaller than the ion-cyclotron (IC) frequency and with polarization properties that are incompatible with both kinetic Alfvén waves (KAWs) and IC waves. At higher frequencies, we clearly identify signatures of both whistler waves and KAWs; however, their energetic contribution to the magnetic power spectrum is negligible. We conclude that the dynamics of 2D Hall-MHD turbulence at sub-ion scales is mainly driven by localized intermittent structures, with no significant contribution of wavelike fluctuations.
Spacetime Hall-MHD Turbulence at Sub-ion Scales: Structures or Waves? / Papini E.; Cicone A.; Franci L.; Piersanti M.; Landi S.; Hellinger P.; Verdini A.. - In: THE ASTROPHYSICAL JOURNAL LETTERS. - ISSN 2041-8205. - ELETTRONICO. - 917:(2021), pp. L12-L19. [10.3847/2041-8213/ac11fd]
Spacetime Hall-MHD Turbulence at Sub-ion Scales: Structures or Waves?
Papini E.
;Franci L.;Landi S.;Hellinger P.;Verdini A.
2021
Abstract
Spatiotemporal properties of two-dimensional (2D) Hall-magnetohydrodynamic (MHD) turbulence at intermediate plasma β = 2 are studied by means of Fast Iterative Filtering (FIF), a new technique for the decomposition of nonstationary nonlinear signals. Results show that the magnetic energy at sub-ion scales is concentrated in perturbations with frequencies smaller than the ion-cyclotron (IC) frequency and with polarization properties that are incompatible with both kinetic Alfvén waves (KAWs) and IC waves. At higher frequencies, we clearly identify signatures of both whistler waves and KAWs; however, their energetic contribution to the magnetic power spectrum is negligible. We conclude that the dynamics of 2D Hall-MHD turbulence at sub-ion scales is mainly driven by localized intermittent structures, with no significant contribution of wavelike fluctuations.File | Dimensione | Formato | |
---|---|---|---|
2107.03843.pdf
accesso aperto
Tipologia:
Pdf editoriale (Version of record)
Licenza:
Open Access
Dimensione
921.03 kB
Formato
Adobe PDF
|
921.03 kB | Adobe PDF |
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.