Attenuation Band and Elctric Field of VLF Saucers

Abstract

An analysis of the ISIS-VLF data and magnetic field data detected by house-keeping magnetometer received at Syowa Station, Antarctica, shows that the electric field component of the saucer emissions is approximately perpendicular to the local geomagnetic field lines. Lower cutoff frequencies of attenuation bands of the saucer emissions are usually at harmonics of the local proton gyrofrequencies (nG_p ; n=2, 3, 4..) around the ISIS satellite Sometimes, upper cutoff frequencies of the attenuation bands are observed at nG_p. The source region of saucers may be located at altitude of 950-1050 km which is estimated from the width of the attenuation bands, assuming that the attenuation bands of saucers are caused by the local cyclotron absorption of low energy protons