Diurnal, seasonal and solar cycle variations of ionospheric electron content over an Indian low latitude station, Waltair

摘要

The diurnal, seasonal and solar cycle variations of the ionospheric electron content (IEC) during both high (1979-80) and low (1984-85) sunspot activity periods at a low latitude station, Waltair (17.7° N, 83.3°E) have been studied. The diurnal variation shows noon bite-out and post-sunset enhancement in IEC during equinoctial and winter months of high sun-spot activity period. The seasonal variation shows minimum IEC during each of the local hours of the day of low sunspot activity period compared to those in the corresponding hours of high sunspot activity period. The results on the diurnal variation of IEC, particularly, during the post-sunset hours of high sunspot activity period are discussed in relation to the effect of E x B drift at the equator.