| dc.description.abstract | In this work, we examine International Reference Ionosphere (IRI)-2016 model and Global
Ionospheric Maps (GIMs) by comparing with observed total electron content (TEC) from
dual-frequency GPS receiver at the magnetic equator. TEC is calculated from GPS data
at International University (10◦520 N, 106◦480 E), Vietnam, in 2018-2019. The calculated
TEC shows the semiannual anomaly, where TEC reaches a maximum in the equinoxes
and minimum in the solstices. GIMs show similar diurnal and seasonal variation, although
calculated TEC results are lower than GIMs in 2-5 TECU. IRI-2016 model results agree
with observed TEC during geomagnetically quiet time. However, during the geomagnetic
storm on August 26, 2018, IRI-2016 did not show any significant changes in TEC, while
observation from our station shows substantial enhancement of TEC during the main and
recovery phase of the storm. | en_US |
