2017/07/31 by N. Andrés, Nahuel Andrés, P. Clark di Leoni +9 · 31 citations
Physics and Astronomy · #Compressibility #Excitation #Ionosphere and magnetosphere dynamics #Mach number #Magnetic confinement fusion research #Magnetic field #Magnetohydrodynamic drive #Magnetohydrodynamic turbulence #Magnetohydrodynamics #Solar and Space Plasma Dynamics #Turbulence #astro-ph.EP #physics.plasm-ph #physics.space-ph
paper · pdf · doi:10.1063/1.4997990
published in Physics of Plasmas 24(10) (American Institute of Physics)
openalex created_date 2017/08/08 · openalex publication_date 2017/10/01 · arxiv created 2018/10/07 · arxiv updated 2018/10/09 · openalex updated_date 2026/08/06
Using spatio-temporal spectra, we show direct evidence of excitation of magnetosonic and Alfvén waves in three-dimensional compressible magnetohydrodynamic turbulence at small Mach numbers. For the plasma pressure dominated regime, or the high β regime (with β the ratio between fluid and magnetic pressure), and for the magnetic pressure dominated regime, or the low β regime, we study magnetic field fluctuations parallel and perpendicular to a guide magnetic field B0. In the low β case, we find excitation of compressible and incompressible fluctuations, with a transfer of energy towards Alfvénic modes and to a lesser extent towards magnetosonic modes. In particular, we find signatures of the presence of fast magnetosonic waves in a scenario compatible with that of weak turbulence. In the high β case, fast and slow magnetosonic waves are present, with no clear trace of Alfvén waves, and a significant part of the energy is carried by two-dimensional turbulent eddies.