Geomagnetic pulsations (5–50 mHz) and the interplanetary magnetic field

摘要: Geomagnetic pulsations in the 10- to 200-s (Pc 3–4) period range as observed at earth's surface are often seen switch on and off during day. Recordings of earth current measurements made three stations United Kingdom (geomagnetic latitude 55°–61°N, L = 2.6–3.6) were compared with interplanetary magnetic field (IMF) by Heos 2 satellite. Some events presented which show a distinct correlation between enhancements radial component IMF amplitude 20–60 s. Computation cross-correlation functions suggests possible diurnal variation delay time step enhancement ground (typically ∼ 15 min). These observations may give important indications generation regions these ULF waves magnetosphere.