Solar control of ambient ionization of the ionosphere near the crest of the equatorial anomaly in the Indian zone
Long-term (1978–1990) total electron content (TEC) data have been analyzed to show the dependence of ambient ionization on EUV radiation from the Sun.TEC observations were made at Calcutta (22.58° N, 88.38° E geographic, dip: 32° N), situated virtually below the northern crest of the equatorial ionization anomaly.Day-to-day change