Theoretical simulation of O + and H + densities in the Indian low latitude F-region and comparison with observations

The O + and H + ion density distributions in the In- dian low latitude F-region, within ±15 magnetic latitudes, are simulated using a time dependent model developed on the basis of solution of the plasma continuity equation. The simulated ion densities for solar minimum June and Decem- ber solstices are then compared with ionosonde observations from the period 1959-1979 and measurements made by the Indian SROSS C2 satellite during 1995-1996 at an altitude of 500 km. The simulated O + density has a minimum around pre-sunrise hours and a maximum during noontime. H + den- sity is higher at nighttime and lower during the day. The simulations reproduced the well-known equatorial ionization anomaly (EIA) observed in electron density at the peak of the F2-region in the Indian low latitude sector during solar minimum. In situ measurement of O + density by the SROSS C2, however, showed a single peak of ionization around the equator.