Conjugacy of magnetic field fluctuations in the period range 2–24 hours

Abstract

Conjugacy of variations in the period range 2 to 24 hours has been examined from coherence spectra of horizontal intensity at stations which are conjugate or nearly conjugate and stations which are in similar dipole latitudes but are not conjugate. The coherence spectra computed for stations located in the auroral zone, on the equatorial side of auroral zone and at low-middle latitudes suggest that, so far as the principal lines in the spectra corresponding to 24, 12 and 8 hours are concerned,magnetic conjugacy is confined to disturbed periods and to stations in the auroral and subauroral zones. In the continuum spectrum, however, the percentages of estimates, for which coherences are statistically significant, are very high for conjugate stations in the auroral zone but decrease progressively for pairs in the equator side of the auroral zone and lower latitudes.