Depolarization of subalfvenic plasma jet generating field-aligned currents Original Research Article

The subalfvenic magnetized plasma jet propagating across the geomagnetic field generates the field-aligned currents in ionospheric plasma. The transverse polarization electric field Ep = −V × B in the jet is reduced due to a leakage of polarization charges through the field-aligned currents (plasma jet depolarization). These phenomena are investigated in the laboratory experiment. It was revealed that the depolarization is accompanied by appearing of the electric field Ea along the plasma velocity vector and creation of an additional pair of the field-aligned currents being generated at the leading and trailing edge of the moving plasma. The value of Ea is comparable with the transverse electric field Ep. The depolarization results in the plasma jet deflection. The possibility of a manifestation of these effects in the NORTH STAR Russian–American active rocket experiment is discussed.