Small‐scale electrodynamics of the cusp with northward interplanetary magnetic field

摘要: We report on possible, low-altitude field signatures of merging occurring at high-latitudes during a period strong, northward directed interplanetary magnetic field. Our study the small-scale electrodynamics in vicinity poleward cusp boundary is based multisensor measurements from single DE 2 satellite pass over northern hemisphere cusp/cleft regions. Observed sunward convection polar cap and presence reverse ion dispersion feature are agreement with expectations for magnetopause, lines mapping to cusp. Large electric spikes detected edge magnetosheathlike particle precipitation interpreted as footprint such line locations. A train phase-shifted, almost linearly polarized fluctuations was just equatorward large electromagnetic spike. These may be due either cyclotron waves excited by penetrating magnetosheath ions or transient oscillations frame convecting plasma, brought about sudden change flow magnetospheric end line.