资源环境科技发展态势分析平台

By establishing two solar-wind convection electric field-associated coordinate systems, the magnetic and plasma properties in the lunar wake are examined. In the plane perpendicular to the interplanetary magnetic field, all the properties exhibit asymmetric distributions related to the electric field, and they are even periodically modulated every 2 lunar radii but only along the flank which the electric field points to. Evidences show that the solar-wind ions, reflected over the dayside lunar magnetic anomalies, have produced these asymmetries and periodical modulations. These ions, undergoing both the electric drift and large-radius gyration, bypass the Moon body and periodically penetrate into the wake flank, during which they exchange momentum with the refilling solar-wind plasma, thereby resulting in the oscillations of the plasma and the periodical modulations of the wake.