STATISTICAL STUDIES OF GIANT PULSATIONS (PGS) - HARMONIC MODE

Thirty-four Pg events have been observed by the EISCAT magnetometer cross. For each of these events the equatorial mass density at the time of the event has been estimated for both a dipole and a more realistic magnetospheric field model. By comparing these results with those of previous studies it has been deduced that Pgs are second harmonic rather than fundamental standing wave oscillations. This is consistent with the bounce resonance mechanism being the driving mechanism for Pgs. The Pg source region in the equatorial plane has also been accurately located.