基于修正Kp指数的中纬区单站电离层暴预报方法研究

A prediction method for midlatitude ionospheric storms at a single station based on modified K_p

对电离层暴进行有效预报具有很重要的实际应用价值,但目前这一工作还存在着许多方面有待改进.本文假设电离层扰动的季节性规律占主导地位,借鉴Kutiev and Muhtarov构建修正K_p指数表示地磁活动的方法,建立了一个适用于中纬地区Yakutsk单台站电离层暴预报的线性经验模型.检验表明,该模型对Yakutsk站夏季和春秋季电离层扰动的预测效果明显优于IRI中的STORM模型,模型改善度平均可达35%左右;能很好地反映磁暴连续发生的情况下δfoF_2分阶段下降的形态;能反映出一定的电离层正相扰动及其持续时间,但是正扰动的预报精度有待进一步提高.

The prediction of the ionosphere during storms is essential for practical applications. In this paper, with the assumption that the seasonal effect is dominant, we develop a linear storm-time empirical model for forecasting of ionospheric storms at a midlatitude station Yakutsk, by introducing a modified function Kf from Kp index which is firstly established by Kutiev and Muhtarov. The validation shows that the predictability of our model is much better than the STORM model of IRI in summer and equinoxes, with an average improvement of 35%. Especially, for the type of geomagnetic storms with two steps main phase, our model can well present twice descending of δfoF2. Moreover, our model can forecast positive ionospheric storms, though its prediction needs to be improved.