Bremen 2000 – wissenschaftliches Programm

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EP: Extraterrestrische Physik

EP 4: Magnetosph
ären und Plasmen

EP 4.5: Vortrag

Mittwoch, 22. März 2000, 11:45–12:00, S3121

Anomalous transport in magnetic flux tubes caused by current-driven turbulence — •C.-V. Meister² and V.E. Zakharov¹ — ¹Kaliningrad Univ. — ²Astrophysical Inst. Potsdam

A magnetohydrodynamic model is developed and numerically solved to study anomalous transport and energization of the thermal and auroral plasma. The magnetic flux tubes of the auroral magnetosphere are given in the empirical data-based Tsyganenko-1995 model. In the magnetic flux tubes, field-aligned electric currents exite the electrostatic ion-cyclotron (EIC) turbulence. Parallel electric fields are present due to the anomalous resistivity of the plasma. The parameters of the background plasma outside the flux tubes and the strength of the electric field of the magnetospheric convection are given. The pitch-angle anisotropy of the auroral plasma is taken into account considering parallel and perpendicular temperatures for both electrons and protons. The calculations are performed for different values of the ratio between the energy densities of the EIC waves and the plasma. It is shown that the parallel difference of the electric potential may be as large as 1-10 kV. The acceleration and heating of the plasma are investigated in dependence on the intensities of turbulence and convection, the location of the magnetic flux tubes, and the value of the magnetic flux in this tube.