The total electron content (TEC) over the Iberian Peninsula was studied using data from two locations obtained both by Global Navigation Satellite System receivers and an ionosonde. The principal component analysis applied to the TEC data allowed us to extract two main modes. Each mode is characterized by a daily TEC variation of a certain type (principal component [PC]) and its amplitude for each of the studied days (given by the empirical orthogonal functions [EOFs]). The variations of these modes as well as the original TEC data were studied in relation to four strongest geomagnetic storms of 2015 and three geomagnetic disturbances of lower amplitude observed during the same months. EOFs were found to correlate well with space weather parameters characterizing solar UV and XR fluxes, number of the solar flares, parameters of the solar wind, and geomagnetic indices. Multiple regression models were constructed to fit EOFs using combinations of the space weather parameters with a lag from 0 to 2 days. Combining the regression models of EOFs with the corresponding PCs, we reconstructed TEC variations as a function of space weather parameters observed in previous days. The possibility to use such reconstructions for the TEC forecasting was also studied.

中文翻译：

---

由于地磁风暴和太阳耀斑，2015年伊比利亚半岛上TEC的变化

使用来自全球导航卫星系统接收器和离子探空仪的两个位置的数据研究了伊比利亚半岛上的总电子含量（TEC）。通过对TEC数据进行主成分分析，我们可以提取两种主要模式。每种模式的特征是特定类型的每日TEC变化（主要成分[PC]）及其在每个研究日中的振幅（由经验正交函数[EOF]给出）。研究了这些模式的变化以及原始TEC数据，分别与2015年的四次最强地磁风暴和在同一月份观测到的三个低振幅地磁干扰有关。发现EOF与空间天气参数具有很好的相关性，这些参数表征了太阳紫外线和XR通量，太阳耀斑的数量，太阳风的参数，和地磁指数。使用空间天气参数的组合构建了多个回归模型以拟合EOF，滞后时间为0至2天。将EOF的回归模型与相应的PC结合起来，我们重建了TEC变化，作为前几天观测到的空间天气参数的函数。还研究了将此类重建用于TEC预测的可能性。