Kinetic scales dominated by magnetic helicity in space plasmas

Abstract

It is shown, using results of fully kinetic 3D numerical simulations and observations in solar wind and Earth's magnetosphere that the transition from deterministic chaos to turbulence at kinetic (sub-ion) scales in space plasmas is generally dominated by magnetic helicity (an adiabatic invariant in a weakly dissipative plasma) directly or through the Kolmogorov-Iroshnikov phenomenology (the magneto-inertial range of scales as a precursor of hard turbulence). The magneto-inertial range of scales at sub-electron scales has been also briefly discussed. Despite the considerable differences in the scales and physical parameters, the results of numerical simulations are in quantitative agreement with the space observations in the frames of this approach.