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Title: THE FORMATION OF ROTATIONAL DISCONTINUITIES IN COMPRESSIVE THREE-DIMENSIONAL MHD TURBULENCE

Measurements of solar wind turbulence reveal the ubiquity of discontinuities. In this study we investigate how the discontinuities, especially rotational discontinuities (RDs), are formed in MHD turbulence. In a simulation of the decaying compressive three-dimensional (3D) MHD turbulence with an imposed uniform background magnetic field, we detect RDs with sharp field rotations and little variations of magnetic field intensity, as well as mass density. At the same time, in the de Hoffman–Teller frame, the plasma velocity is nearly in agreement with the Alfvén speed, and is field-aligned on both sides of the discontinuity. We take one of the identified RDs to analyze its 3D structure and temporal evolution in detail. By checking the magnetic field and plasma parameters, we find that the identified RD evolves from the steepening of the Alfvén wave with moderate amplitude, and that steepening is caused by the nonuniformity of the Alfvén speed in the ambient turbulence.
Authors:
;  [1] ; ; ; ; ;  [2] ;  [3] ;  [4]
  1. SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, 100190, Beijing (China)
  2. School of Earth and Space Sciences, Peking University, 100871 Beijing (China)
  3. Institute for Experimental and Applied Physics, Christian Albrechts University at Kiel, D-24118 Kiel (Germany)
  4. Center of Spacecraft Assembly Integration and Test, China Academy of Space Technology, Beijing 100094 (China)
Publication Date:
OSTI Identifier:
22525552
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 809; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALFVEN WAVES; AMPLITUDES; COMPUTERIZED SIMULATION; DENSITY; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; MASS; PLASMA; ROTATION; SOLAR WIND; TURBULENCE; VARIATIONS; VELOCITY