Examining the Consistency Between Quality-Assured Radio Occultation Data in Bangladesh and IRI Predictions

This study investigates the variability of ionospheric F2-layer peak parameters over Bangladesh analyzing a three-year (2020–2022) data set from the Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) radio occultation (RO) mission. Before delving into this research, this study estimates the quality assurance (QA) to filter out unsuitable electron density profiles (EDP) obtained from COSMIC-2 RO. Descriptive statistics are involved in examining the monthly qualified ratios along with the diurnal and seasonal variation of the reject ratio COSMIC-2 RO. To delve deeper, corresponding to COSMIC-2 RO measurement, the International Reference Ionosphere (IRI-2016) model was run to obtain NmF2 and hmF2 predictions. Our inspection reveals that the COSMIC-2 overall qualified ratio is primarily impacted by hmF2, with a notable decline in June-October 2020 and late 2021. Notably, the unqualified ratio of EDP tends to be higher at night and lower during the day. The ratio shows a decreasing trend from 00:00-05:00 local time (LT) and an increasing trend from 18:00-24:00 LT. Comparison of COSMIC-2 derived F2 peak parameters with IRI model predictions reveals that the IRI predictions agree well with COSMIC-2 observations. From 00:00-06:00 LT, the NmF2 becomes minimum, gradually reaches the maximum around 14:00 LT, and again gradually decreases at around 15:00 LT.