Diurnal variation of enhancement of sudden fluctuations in H in the region of the Indian magnetic equator

Abstract

For the Indian region of the magnetic equator the diurnal variation of enhancement of amplitudes of sudden impulses and fluctuations of development time less than 10 minutes is studied with the observations at Trivandrum, Annamalain8gar and Alibag for the period of I.G.Y. and I.G.C. The expected day-time enhancements at Trivandrum and Annamalainagar are found and to exist, but the diurnal variation of the enhancements does not exactly follow the Sq (H) trend. Nor do the magnitudes of the enhancements for the different hours of the day strictly correspond to enhancements in Sq (H) hourly inequalities, as derived from the night level.. During the night hours there is definitely no enhancement of fluctuations close to the Indian magnetic equator. Actually night-time fluctuations at Annamalainagar are a little larger than those at Trivandrum (station closest to the magnetic equator) and Alibag. Night-time enhancements of fluctuations near the Nigerian and South American magnetic equator found by Onwumechilli and Ogbuehi (1962) are not seen for the region of the Indian magnetic equator. The difference is attributed to differences in the internal electrical conductivities at the different localities.