海南站地基数字测高仪探测的电离层B0与B1参数变化研究OA

Based on the detection data of the digisonde at Hainan station(18.34°N,109.62°E)from 2015 to 2018,the diurnal and seasonal variations of the ionospheric bottomside parameters B0 and B1 in Hainan areas have been analyzed.A comparison was conducted between observed values(B0_Obs,B1_Obs)and the prediction results of the IRI-2020 model(B0_Tab/B1_Tab and B0_Gul).The variability of B0 and B1(expressed as the percentage ratio of the interquartile range to the median)and their correlations with other ionospheric characteristics(hmF2 and M(3000)F2)were also investigated.Results reveal the IRI-2020 model shows prediction deviations in low-latitude regions and its Bil-2000 and Gulyaeva options demonstrate opposite deviation trends.This finding indicates that the model is not fully applicable to the Hainan region and requires improvement.B0 shows a"collapse"phenomenon around sunrise,which is a typical feature of the ionosphere at low latitudes.The B1 parameter shows high variability(～68％)before and after sunrise.It indicates that the ionospheric structure may be relatively unstable during this period.Correlation analysis reveals that both B0 and B1 exhibit strong positive correlations with hmF2 and M(3000)F2 during daytime.These results provide provides observational evidence for improving the applicability of the IRI model in Hainan regions and offers valuable insights for inverting bottom side profile parameters using hmF2 and M(3000)F2.