ULF wave magnetic measurements by CHAMP satellite and SEGMA ground magnetometer array: Case study of July 6, 2002

Abstract

We present the analysis of a Pc 3 geomagnetic pulsation event observed simultaneously by CHAMP and by the South European GeoMagnetic Array SEGMA (1.56 < L < 1.88) during the conjunction of July 6, 2002. Both compressional and transverse oscillations were identified in CHAMP magnetic measurements. A close correspondence between the compressional component and the ground signals is observed. At the same time the joint analysis of space and ground observations clearly indicates the occurrence of a field line resonance at L 1.6. A direct confirmation of the well known 90° rotation of the ULF wave polarization ellipse through the ionosphere is also provided. © 2005 Springer-Verlag Berlin Heidelberg.