Abstract: This paper deals with the response of total electron content of the ionosphere over the Bay of Biscay, the Northeast Atlantic Ocean, to geomagnetic storms observed at Aberystwyth, U. K, from geostationary beacon satellites Intelsat IIF2 and SIRIO during the last ten years. The magneto-ionospheric storms selected belong to maxima of the 20th and 21st solar periods and are around the equinoxes and solstices. It is outlined that in spring months, the longish TEC depletion period appears after positive phase effect of continuous magnetic storm, and on the other hand, the short TEC depletion follows the concentrative magnetic storm. The TEC morphology associating with storms during equinoxes and solstices is influenced by some storm indices such as sudden commencement time and SSC occurrence frequency, season, storm main phase, Dst, Kp, Ap, etc.