In this paper, simultaneous measurements of electron density and ELF elec-tric field by Aureol-3 satellite have been analyzed using high frequency resolutionspectral and cross-bispectral techniques. The detailed analyses of the data shows: first, the peaks in the power spectra of the electric field components are seen at theSchumann resonance frequencies in the high latitude ionospheric topside F regionand second, the harmonics are associated with positive density gradients.