Response of the dawn-side, high-altitude, high-latitude magnetosphere to the arrival of an interplanetary shockwave Original Research Article

We investigate in detail the magnetospheric response observed with instruments on the Polar spacecraft during the arrival of a shock wave on January 10, 1997 at 0105 UT. Magnetic field increases have been observed in the solar wind, the magnetosheath, at the Polar location and on the ground. Particle density increases have been observed in the solar wind, the magnetosheath, but not at the position of the Polar spacecraft. Due to the compression of the magnetosphere we also would have expected a particle density increase, but in fact, a small particle density decrease was observed with low and medium energy particle instruments. The effect is attributed to an electric field pulse that convects downflowing particles onto another trajectory. Polar was located at that time at 8.4 Re, 6.1 MLT and 61.1 MLAT.