Comparative study of ionospheric characteristic parameters obtained by DPS-4 digisonde with IRI2000 for low latitude station in China Original Research Article

Data of foF2, hmF2, B0 and B1 with half hourly interval resolution, which are scaled and deduced from ionograms recorded by DPS-4 digisonde at the low latitude station Hainan, China for the time period of March–August 2002, are analyzed for the diurnal and seasonal variation behavior of the ionosphere using the calculated monthly medians. Comparisons between the observational result and that of the International Reference Ionosphere model (IRI2000) are made. Our present study showed that: (1) For foF2, both CCIR and URSI choices in the IRI model produced reasonably good result during daytime hours, but they underestimated foF2 value for nighttime hours and in some cases also in the afternoon hours. (2) For the peak height hmF2, when the CCIR model for M(3000)F2 is chosen, IRI model results are in a poor agreement with observations, especially during hours spanning from afternoon to pre-sunrise; When the measured M(3000)F2 value is used as the F2 peak input, the IRI-produced hmF2 has a much better agreement with the observed value than when the CCIR model for M(3000)F2 is used. With the measured M(3000)F2, IRI can reproduce quite well the observed features such as the three peaks occurring in the pre-sunrise, near local noon and in the evening hours. However, it still underestimates the observed value during nighttime hours. (3) The bottomside F2 layer thickness parameter B0 given by B0-Gulyaeva choice in IRI2000 is generally in a better agreement with observations than when the newly updated B0-Table choice is used.