NOSE APPROXIMATION METHOD APPLIED TO JOVIAN WHISTLERS

The nose approximation method developed by R L Dowden and G M Allcock [J Atmos & Terr Phys (GB), 33 (1971) 1125] for ground-observed whistle rs has been applied to low dispersion Jovian whistlers observed by Voy ager 1 spacecraft below the Io torus. The minimum electron gyrofrequen cies along the propagation paths have been calculated graphically for three Jovian whistlers and the results obtained are found to be in ver y good agreement with the observed gyrofrequencies. The calculated nos e frequencies of the Jovian whistlers are found to be around 36 kHz wh ich are much above the upper cut-off frequencies of the Jovian whistle rs and hence nose characteristics cannot be observed in such whistlers .