Lower Ionosphere Effect Observed During the June 30, 1992 Total Solar Eclipse

VLF radio signals (12.9 kHz) transmitted from Ω-Argentina were being received in Atibala-Brazil during the total solar eclipse of June 30, 1992. The surface path of the totality affected the VLF propagation path in the sunrise transition period causing a phase delay of 6.4 usec and an amplitude change of 1.3 dB. The ionospheric response to the Sun's obscuration was compared to the phase delays reported for several solar eclipses tha t occurred from 1966 to 1979. The results are mainly discussed in terms of the length of VLF propagation path affected.