Low solar activity variability and IRI 2007 predictability of equatorial Africa GPS TEC

Latitudinal variation of the ionosphere in the African sector using GPS TEC data

“…This meridional wind changes the neutral composition and O/N 2 increase at equatorial and low latitude stations (Mendillo, 2006;Rama Rao et al, 2006;Adewale et al, 2012). The increase at F 2 region will be maximum resulting into high electron density.…”

“…Investigations by Stolle et al (2008), Adewale et al (2012), Rama Rao et al (2006), D'ujanga et al (2012, D'ujanga et al (2013), Kumar and Singh (2009), Wielgosz et al (2004), Chauhan et al (2011) based on GPS TEC data indicated that the equatorial ionosphere http://dx.doi.org/10.1016/j.asr.2014.12.036 0273-1177/Ó 2015 COSPAR. Published by Elsevier Ltd. All rights reserved.…”

“…In Africa ionospheric researches using GPS TEC have been carried out in some places. Adewale et al (2012) focused on equatorial Africa to determine the TEC variability during the low solar activity of the year 2007, D'ujanga et al (2013) used TEC from two stations located in KampalaUganda and Nairobi-Kenya, Oron et al (2013) studied the diurnal variation using a single station in KampalaUganda, Fayose et al (2012) looked at the variation over Akure, Nigeria, Zoundi et al (2012) looked at seasonal variation in West Africa, Olwendo et al (2012), used GPS-SCINDA to study the correlation between TEC and Scintillation over the Kenyan Region and South Africa, Yizengaw et al (2012) compared storm time equatorial ionospheric electrodynamics in the African and American sectors, Ngwira et al (2013) carried out simultaneous observations of ionospheric irregularities in the African low-latitude region, Habarulema et al (2013) made a comparative study of TEC response for the African equatorial and mid-latitudes during storm conditions, whereas Amabayo and Pierre (2013) used multi-station observation of ionospheric irregularities over South Africa during strong geomagnetic storms among others.…”

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

“…The IRI is an empirical standard model sponsored by the Committee on Space Research (COSPAR) and the International Union of Radio Science (URSI) (Bilitza et al, 1990). Several papers have been published on the simultaneous measurement of foF2/TEC, its noontime bite-out and secondary peak during evening, winter anomaly, solar activity dependance, and corresponding model predictions in the equatorial and low latitudes (Sethia et al, 1979;Dabas et al, 1984;McNamara, 1985;Rastogi and Klobuchar, 1990;Batista et al, 1994;Abdu et al, 1996;Ezquer et al, 1999;Sethi et al, 2001Sethi et al, , 2011Rao et al, 2006;Bhuyan and Borah, 2007;Bagiya et al, 2009;Chauhan and Singh, 2010;Aggarwal, 2011;Adewale et al, 2012;Prasad et al, 2012;Olwendo et al, 2012;Bhuyan and Hazarika, 2013;Sur and Paul, 2013;Hazarika and Bhuyan, 2014;Kumar et al, 2014a). Efforts are also being made to update and improve the model since its development in 1969, with newer data and better modeling techniques.…”

Spatial distribution of TEC across India in 2005: Seasonal asymmetries and IRI prediction

“…Including both URSI and CCIR coefficients in IRI-2007, Aggarwal (2011 reported that the predicted TEC near the crest of EIA region is better represented by IRI01-corr using CCIR coefficient or in general the predicted TEC shows good agreement for low solar activity. Adewale et al (2012) also reported that Ne Quick predictions provided an improvement in IRI 2007 model at African equatorial stations.…”