电离层模型IRI-2016的NmF2和HmF2参数在平静期的误差分析

Error Analysis on NmF2 and HmF2 Parameters of IRI-2016 Ionospheric Model during Magnetically Quiet Periods

国际参考电离层模型IRI(the international reference ionosphere model)是利用全球电离层测站以及卫星观测数据建立的电离层经验模型,并广泛用于电离层研究领域.本文选用2014年地磁暴平静期的IRI-2016模式和电离层垂测仪的数据,对电离层F2层峰值电子密度NmF2和峰值高度HmF2两个物理量,通过IRI模型最新版本(IRI-2016)在地磁环境平静期的误差精度进行评估.根据不同磁倾角范围分别选择5个台站(Juliusruh(54°N,13°E)磁倾角:68.54°,Okinawa(26°N,128°E)磁倾角:37.26°,Jicamarca(12°S,77°W)磁倾角:-0.26°,Port_Stanley(52°S,58°W)磁倾角:-51.20°,Hermanus(34°S,19°E)磁倾角:-64.24°)进行NmF2和HmF2参数对比分析.5个台站中Port_Stanley站的NmF2相关性最差(相关系数0.68),Okinawa站HmF2相关性最差(相关系数0.52),Juliusruh站两个参数的相关性最高(相关系数0.87).以Juliusruh站为例进行白昼、夜晚以及不同季节的分析,可以看出白昼误差明显低于夜晚,相较于分季(春或秋)和冬季,IRI模型在夏季预测效果最好.5个台站的研究结果表明,IRI模型与垂测仪数据具备一致性,IRI模型的值高于实测数据值.

The international reference ionosphere（IRI）model has been widely utilized in ionospheric research.It is an empirical ionosphere model based on worldwide available data of ground-based and satellite observations.In this paper,the NmF2 and HmF2data of IRI-2016 model and ionosonde data during geomagnetic quiet periods in 2014 have been selected for a comparison study to estimate the accuracy and precision of the IRI-2016 model.This paper chooses five stations（Juliusruh（54°N,13°E）：68.54°,Okinawa（26°N,128°E）：37.26°,Jicamarca（12°S,77°W）：-0.26°,Port_Stanley（52°S,58°W）：-51.20°,Hermanus（34°S,19°E）：-64.24°）from different geomagnetic dip zones to compare and analyze NmF2 and HmF2parameters.NmF2 data showed the worst correlation（r=0.68）in Port_Stanley of the five stations and HmF2 data showed the worst correlation（r=0.52）in Okinawa of the five stations.Juliusruh had the highest correlation（r=0.87）,both for NmF2 and HmF2.In the case of Juliusruh,analysis on day and night and seasonal characteristics indicated that the error in daytime was obviously lower than that in nighttime.Compared withwinter and equinoxes,summer has the best agreement in IRI model.The results of five stations showed that IRI predictions had a good agreement with ionosonde data both for the NmF2 and HmF2,and IRI predictions systematically were higher than the observed results.