Transport of thermal plasma above the auroral ionosphere in the presence of electrostatic ion-cyclotron turbulence
[摘要] The electron component of intensive electriccurrents flowing along the geomagnetic field lines excites turbulence in thethermal magnetospheric plasma. The protons are then scattered by the excitedelectromagnetic waves, and as a result the plasma is stable. As the electron andion temperatures of the background plasma are approximately equal each other,here electrostatic ion-cyclotron (EIC) turbulence is considered. In thenonisothermal plasma the ion-acoustic turbulence may occur additionally. Theanomalous resistivity of the plasma causes large-scale differences of theelectrostatic potential along the magnetic field lines. The presence of thesedifferences provides heating and acceleration of the thermal and energeticauroral plasma. The investigation of the energy and momentum balance of theplasma and waves in the turbulent region is performed numerically, taking themagnetospheric convection and thermal conductivity of the plasma into account.As shown for the quasi-steady state, EIC turbulence may provide differences ofthe electric potential of Δ
V≈1–10 kV at altitudes of500 <
h < 10 000 km above the Earth's surface. In the turbulentregion, the temperatures of the electrons and protons increase only a few timesin comparison with the background values.
Key words. Magnetospheric physics (electric fields;plasma waves and instabilities)
