During this year we celebrate 20 years of continuous generation and improvement of global ionospheric maps (GIM) of vertical total electron content (VTEC) in the context of the International GNSS Service (IGS, see for instance Roma- Dollase et al. 2018). We present the time series of the vertical distribution of polar electron content derived from the most daily-basis tomographic runs performed by one of the IGS ionospheric analysis centers: UPC-IonSAT (Hernández- Pajares et al. 1999). We will focus in particular on two points: (1) in the comparison of the derived ionospheric effective height with other approaches, and (2), in the study of the predictability of the top side electron content fraction which might lead to the extension of the Barcelona Ionospheric Mapping Function (BIMF-nml, Lyu et al. 2018) to polar regions, with the associated potential improvement for GNSS users in such regions.