ULF PULSATIONS IN A MAGNETOSPHERIC WAVE-GUIDE - COMPARISON OF REAL AND SIMULATED SATELLITE DATA

The representation of the Earth's magnetosphere as an MHD waveguide ha s prompted much recent speculation. In particular, the signatures asso ciated with ULF pulsations sit well within the waveguide concept. We f urther explore the appositeness of the waveguide model by simulating d ata that a spacecraft would see when passing through a stimulated magn etospheric waveguide and by comparing the results with those obtained from a real spacecraft. We find that the waveguide results again compa re favorably and can explain many features seen in the data. We also f ind that the magnetometer signature of the fast mode in a waveguide (u nlike a cavity) does not have a regular oscillatory nature with consta nt period over a range of L shells.