000005781 001__ 5781
000005781 005__ 20220509085412.0
000005781 0247_ $$2DOI$$a10.1051/0004-6361/202142362
000005781 037__ $$aSCART-2022-0062
000005781 088__ $$aaa42362-21
000005781 100__ $$aShestov, Sergei
000005781 245__ $$aInitiation of Alfvénic turbulence by Alfvén wave collisions: A numerical study
000005781 260__ $$c2022
000005781 520__ $$aIn the framework of compressional magnetohydrodynamics (MHD), we numerically studied the commonly accepted presumption that the Alfvénic turbulence is generated by the collisions between counter-propagating Alfvén waves (AWs). In the conditions typical for the low-beta solar corona and inner solar wind, we launched two counter-propagating AWs in the three-dimensional simulation box and analyzed polarization and spectral properties of perturbations generated before and after AW collisions. The observed post- collisional perturbations have different polarizations and smaller cross-field scales than the original waves, which supports theoretical scenarios with direct turbulent cascades. However, contrary to theoretical expectations, the spectral transport is strongly suppressed at the scales satisfying the classic critical balance of incompressional MHD. Instead, a modified critical balance can be established by colliding AWs with significantly shorter perpendicular scales. We discuss consequences of these effects for the turbulence dynamics and turbulent heating of compressional plasmas. In particular, solar coronal loops can be heated by the strong turbulent cascade if the characteristic widths of the loop substructures are more than ten times smaller than the loop width. The revealed new properties of AW collisions have to be incorporated in the theoretical models of AW turbulence and related applications.
000005781 594__ $$aNO
000005781 6531_ $$amagnetohydrodynamics (MHD)
000005781 6531_ $$aturbulence
000005781 6531_ $$aplasmas
000005781 6531_ $$amethods: numerical
000005781 700__ $$aVoitenko, Yuri
000005781 700__ $$aZhukov, Andrei
000005781 773__ $$cA93$$pAstronomy & Astrophysics$$v661$$y2022
000005781 8560_ $$fsergei.shestov@observatoire.be
000005781 85642 $$ahttps://www.aanda.org/10.1051/0004-6361/202142362
000005781 905__ $$apublished in
000005781 980__ $$aREFERD