Diurnal Variation of Geomagnetic SFEs & SSCs at Hyderabad

Abstract

Diurnal variation plots or amplitudes or solar flare effects (SFEs) in <i>H, D </i>and Z components of the geomagnetic field as recorded at Hyderabad during 1967-74 for the three seasons, are given and salient features pointed out. Changes in the signs of amplitudes of the crochets in the three elements are attributed to the changing overhead ionospheric SFE or Si/-current system from morning to evening, The SFE current system appears to be located sometimes in the D layer and sometimes in the E layer. Diurnal variations of occurrence frequency, amplitudes and rise-times of storm sudden commencements (SSCs) observed in Hat Hyderabad during 1965-74 are also presented and discussed. Relationship between amplitude and rise-time of SSCs is investigated for amplitudes less than 25ϒ and for those greater than 25ϒ separately.