  The total electron content (TEC) over the Iberian Peninsula was modelled
using PCA-MRM models based on decomposition of the observed TEC series using
the principal component analysis (PCA) and reconstruction of the daily modes
amplitudes by a multiple linear regression model (MRM) using space weather
parameters as regressors. The following space weather parameters are used:
proxies for the solar UV and XR fluxes, number of the solar flares of different
classes, parameters of the solar wind and of the interplanetary magnetic field,
and geomagnetic indices. Time lags of 1 and 2 days between the TEC and space
weather parameters are used. The performance of the PCA-MRM model is tested
using data for 2015, both geomagnetically quiet and disturbed periods. The
model performs well for quiet days and days with solar flares but without
geomagnetic disturbances. The MAE and RMSE metrics are of the order of 3-3.5
TECu for daytime and about 2 TECu for night-time. During geomagnetically
disturbed periods the performance of the model deteriorates but only for
daytime: MAE and RMSE are of the order of 4.5-5.8 TECu and can rise to about 13
TECu for the strongest geomagnetic storms.
