Analysis of Ionospheric TEC Variation over Manama, Bahrain, and Comparison with IRI-2012 and IRI-2016 Models

Abstract

In this paper, we investigate the ionospheric total electron content (TEC) variations over Manama, Bahrain, through Global Positioning System (GPS) observations from an International GPS Services (IGS) station (BHR3, 26.21 $$^{\circ }$$ N, 50.61 $$^{\circ }$$ E) during the period January 2016 to October 2017. The estimated vertical TEC (VTEC) from International Reference Ionosphere (IRI-2012 and IRI-2016) models is compared with the GPS-derived TEC to evaluate their effectiveness over the region. Diurnal variation of VTEC demonstrates highest value ( $$\sim $$ 20 TECU) around 10.00 UT, which thereafter declines to attain the lowest value after midnight. However, both the versions of IRI model overestimated GPS-VTEC during daytime and underestimated during nighttime with exception to few hours surrounding dusk and dawn period when the IRI models almost approximate the observed value. The monthly behavior of VTEC indicates the highest value ( $$\sim $$ 30 TECU) of GPS-VTEC during February 2016 to April 2016, while the lowest value ( $$\sim $$ 17 TECU) in GPS-VTEC is obtained during November 2016 to January 2017. The highest percentage deviation between the IRI models and GPS-VTEC is observed to be up to 40% during July 2016 which further increases to reach a level of even more than 60% in nighttime in majority of the months. The underestimation of IRI models during the summer season of the year 2016 is found $$\sim $$ 9 TECU, and same season for the year 2017 is found $$\sim $$ 5 TECU. The difference between IRI-2016 and IRI-2012 indicates the improvements in IRI-2016, though it needs further refinements in the present version for relatively realistic predictions irrespective of latitudes and longitudes. Our results may be useful for navigational and modeling improvements over the Bahrain territory.