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国际参考电离层模型(IRI)是非常有影响的电离层经验模型之一,利用该模型对我国东亚地区,尤其是海南低纬度地区,进行长期预测的效果尚未研究。通过对一个太阳活动周(2002~2012年)期间海南观测站(19.5°N,109.1°E)数字测高仪DPS-4D观测到的电离层临界频率foF2在低地磁扰动条件下的月中值日变化、季节变化和年变化进行了分析;并与相应的IRI-2012模型预报值进行了对比研究。结果表明:1观测到的foF2存在着明显的冬季异常和半年异常现象,对太阳活动存在着明显的依赖关系;2IRI-2012模型预报值虽给出了海南foF2的基本观测特征,但细节上IRI模型预测值与观测值还是存在着地方时、季节和年度偏差,主要表现为:在太阳活动低年模型存在高估;在太阳下降年期间模型存在低估;在太阳活动较高时期模型存在明显的分季低估,冬、夏季高估;整体上,多数偏差率在±20%以内。偏差率较大的时段主要集中在0500-0800LT,这与以前研究结果基本一致。这些结果对进一步完善IRI模型,尤其是在中国低纬度地区foF2预测参数方面,具有重要的参考价值。
The International Reference Ionospheric Model (IRI) is one of the most influential ionospheric empirical models. The effect of this model on the long-term prediction of East Asia, especially in the low latitudes of Hainan, has not been studied. Based on the mid-term median ionospheric frequency foF2 observed by Digital Altimeter DPS-4D at Hainan Observatory (19.5 ° N, 109.1 ° E) during a solar week (2002 ~ 2012) Diurnal variation, seasonal variation and annual variation were analyzed and compared with the corresponding IRI-2012 model predictions. The results showed that: 1 observed foF2 obvious winter anomaly and six months anomaly, there is a clear dependence on solar activity; 2IRI-2012 model predictive value of Hainan foF2 given the basic observation characteristics, but the details on the IRI There are still local time, seasonal and annual deviations between predicted and observed values of the model, mainly as follows: there is an overestimation in the model of solar activity in the low year, underestimation of the model in the solar year of decline, and obvious Sub-quarter underestimate the winter and summer overestimated; on the whole, the majority of the deviation rate within ± 20%. Deviation rate of the time period is mainly concentrated in the 0500-0800LT, which is basically the same with the previous study. These results have important reference value for further improvement of the IRI model, especially for the foF2 prediction parameters in low latitudes of China.