Effect of magnetic storms and substorms on the low- latitude/ equatorial ionosphere

Magnetic storms and substorms occupy the center stage of research in Solar-Terrestrial Physics as they epitomize the couplings within the Sun-Earth system. Noteworthy progress has been achieved in recent times in understanding the solar and interplanetary cause(s) of magnetic storms and the storm-associated disturbances in the terrestrial magnetospheric and upper atmospheric environment, which collectively constitute an easily identifiable form of ‘Space Weather’. In this paper, I shall endeavor to present a brief summary of recent studies of the effect of magnetic storms and substorms on the low latitude/equatorial ionosphere properties, profiling the incremental additions to our understanding of the storm/substormrelated disturbances. The outstanding scientific questions that warrant further work are projected which include the manifestation at the day side dip equator of storm sudden commencement (ssc or sc) and geomagnetic and ionospheric effects of substorms of various types, appearance and interplay of electric field disturbances due to prompt penetration (pp) and ionospheric disturbance dynamo (IDD) processes, and impact of the electric field disturbances on the generation of equatorial ionospheric F region irregularities (ESF) that are detrimental to trans-ionospheric telecommunications.