Precipitating Polar Cap Particles during Northward IMF (Interplanetary Magnetic Field)

摘要

We have studied the global features of high-latitude precipitating particles during a fifteen hour period of stably northward, toward sector interplanetary magnetic field (IMF). Thiry passes of DMSP precipitating electron and ion measurements enabled us to examine the average polar cap particle intensity, morphology and characteristic spectra. Large scale regions of ion enhancement, with energy spectra similar to those for boundary plasma sheet ions, are associated with polar cap arcs. The high latitude precipitation patterns for each hemisphere are nearly mirror images, thereby showing an IMF sector (or By) dependence. Keywords: Charged particles; Polar cap arcs; Boundary plasma; Northward Bz; Electron precipitation; Ion precipitation; DMSP satellite; Reprints. (EDC)