Electron and ion temperature and electron density at ±10° magnetic latitudes from SROSS C2 measurements over India and comparison with the IRI

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 (2002a) from comparison of SROSS C2 measured electron temperature at ∼ 500 km with that predicted by the IRI-95 have found that the model predicts nighttime electron temperature well within ∼ 100 K of observation, but at other local times, the predicted Te is less than that measured in all seasons. The ion temperature measured by SROSS C2 at ±10 • magnetic latitude was also found to be di erent from that predicted by the IRI at about all local times (Bhuyan et al, 2002b). Present observation indicates that the IRI overestimates ion temperature at low and equatorial latitudes at about all local times.…”

“…The disagreement was found to be greatest in equinox and minimum in summer. Bhuyan et al (2002b) have reported that the IRI-90 overestimates the electron density measured by the SROSS C2 satellite at ∼ 500 km over 10 • S and 10 • N magnetic latitudes in the Indian zone in all seasons during the low activity period of 1995 -1996. 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.…”

Validation of IRI-2007 against TEC observations during low solar activity over Indian sector

“…In view of these discrepancies, attempts were made by many workers to improve the representation of bottomside electron density distribution in the IRI model at low latitudes, and their inputs led to improved version of IRI model, IRI-2001(Bilitza, 2001. Since, the contribution to TEC comes also from the topside (above the F2-peak) electron density distribution, a few comparisons of topside electron density with the IRI model at low latitudes during low solar activity by previous workers have shown discrepancies (Pandey et al, , 1997Bhuyan et al, 2002Bhuyan et al, , 2003. Here too, overestimation of electron density predicted by the IRI model in the topside has been reported by these workers.…”

Morning Overshoot of Electron Temperature as Observed by the Swarm Constellation and the International Space Station

“…As more and more electrons are produced with the progress of the morning (and more sunlight), the energy to share per electron is reduced. Thus, the electron temperature, after reaching a maximum near sunrise, decreases and attains a steady value by the end of the morning (Bhuyan et al, ; Oyama, Balan, et al, ; Oyama, Watanabe, et al, ). Note that not only electron temperature but also ion temperature has been observed to increase near sunrise (Alexander, ; Chao et al, ).…”