Radiations at Twice the Solar-Wind Plasma Frequency Upstream of the Earth's Bow Shock.

Abstract

Radiations at twice the plasma frequency, Fpe, have been commonly observed in the foreshock regions upstream of the Earth's bow shock and far beyond. These electromagnetic radiations are thought to be produced in the electron foreshock and most probably close to the interplanetary magnetic field line tangent to the shock surface. They are often seen simultaneously with suprathermal electrons that are energized at the shock and are backstreaming from it. The objective of the current presentation is to show and discuss 2Fpe radiation events recorded onboard the four CLUSTER spacecraft by the WHISPER relaxation sounder