Variations in the peak parameters of the ionospheric F2-layer over middle latitudes as it was observed and model-simulated

BURESOVA, D., LEE-ANNE MCKINNELL, DAGMAR NOVOTNA , TEREZA SINDELAROVA , MARTA MOSERT , MBAMBO MAKHANGELA

Brugge, Belgica

Otro; Sixth European Space Wather Week; 2009

This paper presents results of the analysis of the ionospheric F2 layer peak parameters variation for different solar activity conditions over middle latitudes. The analysis was carried out using hourly foF2 and hmF2 values derived from electron density profiles obtained at selected ionospheric stations from the Northern (NH) and Southern hemisphere (SH). We studied the daily, semi-annual and annual variation of the peak parameters and the latitudinal and longitudinal dependence of the variation. Effects of severe space weather events on the regular F2 peak variation have also been analysed. The observations were compared with predicted parameters from the IRI2007 and Global Neural Network (NN) model outputs. IRI2007 fails to simulate an alternation of the ionospheric storm phases, and, in general, does not provide a good representation of the variation of the mean night-time foF2 values. The quiet time hmF2 above NH middle latitudes is better represented by IRI during winter and summer months, while at SH middle latitudes the model simulates hmF2 variability more successfully during summer and equinoxes. In some cases the global NN model results showed a significant improvement over the IRI 2007 model, however, in general the improvement is not substantial for storm time periods, which is to be expected since the NN produces in general an average quiet time model. Our results indicate the importance of fully understanding the local patterns of the F2 layer peak parameter variations for the development of global models.