Electron density measurements in the topside F-region and its comparison with the IRI in the 75°E longitude sector

Study of Ionospheric TEC from GPS observations and comparisons with IRI and SPIM model predictions in the low latitude anomaly Indian subcontinental region

“…The GPS derived TEC is compared with the standard IRI and SPIM model predictions to examine reliability of the models over the low latitude Indian region. Past studies of Abdu et al (1996), Bhuyan and Chamua (2002), Iyer et al (1996), Bittencourt and Chryssafidis (1994) and Kumar et al (2014b) report IRI overestimates electron density/TEC during solar minimum and underestimates during solar maximum, and shows comparatively good agreement during intermediate solar activity in the Indian and Brazilian sectors. The deviation is maximum in equinox and minimum in summer (Mukherjee et al, 2010).…”

Solar activity dependence of electron and ion temperatures using SROSS C2 RPA data and comparison with IRI model

“…Within an hour or two, the electron densities rise and cause electron cooling and restore T e to a lower equilibrium value. A secondary maximum is also observed before sunset (Otsuka et al, 1998;Bhuyan and Chamua, 2002). Afternoon enhancement in T e at the low-latitude region is observed to be strongly affected by both the EXB drift and the neutral wind .…”

Diurnal, seasonal and latitudinal variations of ion temperature measured by the SROSS C2 satellite in the Indian zone equatorial and low latitude ionosphere and comparison with the IRI

“…Bhuyan et al (2003) showed that the IRI-95 also predicts higher electron density at ∼ 500 km within the latitude range of 10 • S-15 • N along 75 • E in all seasons and at all local times. The deviation of electron density predicted by the IRI from in situ measurements at the topside changes from overestimation at solar minimum to underestimation at solar maximum (Bhuyan and Chamua, 2002). On the other hand, only a few reports of comparison of IRI predicted electron and ion temperature with those measured in the topside region of the ionosphere are available so far.…”

“…Local time variation of H + density measured by SROSS C2 at ∼ 500 km over the magnetic equator at 75 • E during . Williamson, 2000Bhuyan and Chamua, 2002;Bhuyan et al, 2003). Bhuyan and Chamua (2002) have compared the electron density predicted by the IRI-95 at the height of ∼ 600 km in the 75 • E longitude sector with the electron density measured by the Hinotori satellite within ±25 • of the geomagnetic equator.…”

“…Williamson, 2000Bhuyan and Chamua, 2002;Bhuyan et al, 2003). Bhuyan and Chamua (2002) have compared the electron density predicted by the IRI-95 at the height of ∼ 600 km in the 75 • E longitude sector with the electron density measured by the Hinotori satellite within ±25 • of the geomagnetic equator. They found that the model underestimates the observed electron density in all seasons and at about all local times during moderate and high solar activity.…”