Properties of Hall-MHD Turbulence at Sub-Ion Scales: Spectral Transfer Analysis

0551573 - ÚFA 2022 RIV CH eng J - Journal Article
Papini, E. - Hellinger, Petr - Verdini, A. - Landi, S. - Franci, L. - Montagud-Camps, V. - Matteini, L.
Properties of Hall-MHD Turbulence at Sub-Ion Scales: Spectral Transfer Analysis.
Atmosphere. Roč. 12, č. 12 (2021), č. článku 1632. E-ISSN 2073-4433
Institutional support: RVO:68378289
Keywords : space plasmas * turbulence * numerical simulations * energy dissipation
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.110, year: 2021
Method of publishing: Open access
https://www.mdpi.com/2073-4433/12/12/1632

We present results of a multiscale study of Hall-magnetohydrodynamic (MHD) turbulence, carried out on a dataset of compressible nonlinear 2D Hall-MHD numerical simulations of decaying Alfvenic turbulence. For the first time, we identify two distinct regimes of fully developed turbulence. In the first one, the power spectrum of the turbulent magnetic fluctuations at sub-ion scales exhibits a power law with a slope of & SIM: -2.9, typically observed both in solar wind and in magnetosheath turbulence. The second regime, instead, shows a slope of -7/3, in agreement with classical theoretical models of Hall-MHD turbulence. A spectral-transfer analysis reveals that the latter regime occurs when the energy transfer rate at sub-ion scales is dominated by the Hall term, whereas in the former regime, the governing process is the dissipation (and the system exhibits large intermittency). Results of this work are relevant to the space plasma community, as they may potentially reconcile predictions from theoretical models with results from numerical simulations and spacecraft observations.
Permanent Link: http://hdl.handle.net/11104/0326884