Attenuation distance of low frequency waves upstream of the pre‐dawn bow shock: GEOTAIL and ISEE 3 comparison

Abstract

We have made a statistical study of the spatial distribution of low frequency waves (∼0.01–0.1 Hz) in the region upstream of the pre‐dawn to dawn side bow shock (−50 Re < X < 15 Re) using both GEOTAIL and ISEE‐3 magnetometer data. We have found that the wave amplitude dependence on D and Xs, where D is the distance from the bow shock and Xs the x‐coordinate position of shock foot point of the IMF, can be described by a functional form of A exp(Xs/LX ‐ D/LD), with the characteristic attenuation distances, LX = 62 ± 12 Re and LD = 59 ± 38 Re.