On ionospheric pre-storm phenomena

A study of the ionospheric pre-storm phenomena is presented using global ionosonde and geophysical data obtained during November 20-21, 2003. The results show that pre-storm phenomena don't originate from local time effect. Also a probable role by the magnetospheric electric fields as the main drivers of pre-storm phenomena could not be confirmed by the analysis of hmF2 from the ionosonde stations. Furthermore, investigation of solar flare effects on the pre-storm phenomena didn't reveal them as the main drivers. The present results appear to suggest that pre-storm ionospheric phenomena exist but remain an unresolved problem.