Ionospheric Observations at Madras During the I.G.Y. and I.G.C.

Abstract

During the International Geophysical Year and the International Geophysical Cooperation, the Ionospheric Station of All India Radio at Madras took part in the regular programme of observations. An analysis of some of the characteristics of the ionosphere from the data collected during the period 1957–59 is dealt with in this note.

The diurnal variation of the critical frequency and the height of maximum ionization follow the trend in other ‘equatorial’ stations. The occurrence of spread echoes follows the ‘equatorial’ pattern and has an inverse relationship with geomagnetic activity. Sporadic E is common during day-time but the values of fEs are significantly lower than those observed at equatorial stations like Trivandrum, Tiruchirapalli and Huancayo.