Topology of Magnetic and Velocity Fields at Kinetic Scales in Incompressible Plasma Turbulence

J. ZHANG; SHIYONG HUANG; FOUAD SAHRAOUI; NAHUEL ANDRÉS; ET AL.

JOURNAL OF GEOPHYSICAL RESEARCH

AMER GEOPHYSICAL UNION

Año: 2022

0148-0227

The topology of the magnetic and velocity fields at the kinetic scales are investigated in thecontext of nearly-incompressible magnetosheath plasma turbulence. Using the unprecedentedhigh-resolution data from the Magnetospheric MultiScale (MMS) mission, the joint probabilitydistribution functions of geometrical invariants characterizing the magnetic and velocity fieldsgradient tensor at the kinetic scales are computed. The topological features of the magnetic andvelocity field gradient tensors and their symmetric component tensors present axisymmetricdistribution patterns, indicating that the structure of the plasma turbulence at the kinetic scalesare different from those in hydrodynamic and magnetohydrodynamic (MHD) turbulence.Moreover, a strong correlation between the straining and rotational parts of the magnetic andvelocity field gradient tensors was found, which manifests the dominance of sheet-likestructures at the kinetic-scales dissipation in incompressible plasma turbulence.