The role of electric fields in sporadic E layer formation over low latitudes under quiet and magnetic storm conditions

The low latitude ionospheric F layer descends (indicated by the dashed lines) under westward polarity of a magnetospheric electric field that penetrates to the ionosphere during the development or recovery of a magnetic storm. The F layer descent is accompanied by formation of sporadic E layer near 100 km. (M. A. Abdu, J. R. Souza, I. S. Batista, J. H. A. Sobral, R. G. Rastogi and H. Chandra, JASTP, 2013)