Generation of enigmatic equatorial ionospheric plasma blobs during the 17 March 2015 super geomagnetic storm period over the Indian region.

In general, during geomagnetic storm times, equatorial ionospheric plasma bubbles (equivalently plasma depletions) will be generated due to the effect of prompt penetration of magnetosphere-associated disturbed electric fields to the magnetic equatorial region through polar ionosphere under proper background ionosphere conditions. For the 17 March 2015 super geomagnetic storm event, many reports were published elsewhere on observation of generation of equatorial plasma bubbles particularly over the Indian region using ground-based very-high-frequency radars, airglow imagers, Global Positioning Satellite System (GPS) receivers and space-based satellite measurements. Almost all these reports missed to report correctly on this event and even made wrong claims that they observed the generation of equatorial plasma bubbles. The present report makes clarification here by properly scrutinizing the airglow imager data obtained over the Indian station of Gadanki that actually on that day ionospheric plasma "blobs" (plasma enhancements) rather than plasma bubbles were generated during the local evening sunset time. In the later mid-night hours, it is observed the generation of small scale (few km) plasma bubbles from the eastern-walls of plasma blobs. The present work makes it clear that the concept of enhancement in the equatorial ionosphere electron density and the generation of ionospheric plasma blobs during geomagnetic storm period needs to be well taken into account in the physics-based global ionospheric models like the Whole Atmospheric Community Climate - Extended (WACCMX) and SAMI3 is the another model of the ionosphere (SAMI3) as they failed to generate them as reported elsewhere. Further it stresses the importance of successful prediction of severely-modified ionosphere-conditions particularly during geomagnetic storm periods as flawless radio communications between the earth and the outer space face huge challenges even today.