On the Variation of Geomagnetic H-Component during Solar Quiet Days

The hourly variation of the H-component of the geometric field from two equatorial electrojet stations, Huancayo and Addis Ababa, and one non-equatorial electrojet station, Alibag, were studied to find out the trend of solar quiet variation of H for the year 2008. The dH amplitudes of the electrojet stations showed enhancement in H, while there was no enhancement in the non-electrojet station which was located far away from the dip equator. The day-to-day monthly diurnal variation was, however, observed in all the three stations. Also, at nighttime, the dH amplitudes of all the stations were non-zero which we attributed to non-ionospheric current sources like the magnetosphere since at night there was no solar radiations. For seasonal variations, an Equinoctial maximum, J-Solstitial maximum, and S-Solstitial maximum were observed in the equatorial stations while the non-equatorial station recorded an equinoctial minimum, J-solstitial minimum and D-Solstitial minimum.