Datensatz

Zusammenfassung

Significant accumulated evidence indicates that the magnetosphere can be considered as a turbulent wake formed by the solar wind behind the Earth. The presence of turbulence observed in many regions constrains the repertoire of methods to describe such plasmas, leaving the balance of total - plasma, magnetic, and dynamic - pressure at large scales as one of the most important conditions for the correct description of magnetospheric dynamics. Any local violation of the conservation of total pressure would alter plasma transport and lead to an increase in geomagnetic activity. Despite turbulence, the plasma in the inner magnetosphere is in magnetostatic equilibrium, and plasma pressure gradients determine the configuration of currents. In turn, the close Region 1 field-aligned currents generates the dawn-dusk electric field, which defines the largest scale of magnetospheric turbulence. Therefore, both plasma pressure and turbulence should be studied in a self-consistent way. Data from the THEMIS and CLUSTER satellites and the SuperDarn network were used to study the plasma sheet stability during quiet and disturbed geomagnetic conditions. It was found that the dawn-dusk electric field potential is the key parameter for the development of large- and medium- scale turbulence. The presence of turbulence and the ratio between the Alfvén and plasma velocities are also important for the evaluation of the applicability of a hydrodynamic approach to the analysis of large-scale magnetospheric dynamics, the mechanisms leading to the stochastization and unmagnetization of the particle motion in the turbulent plasmas, and formation of energetic tails in the particle distribution functions.