Low Magnetic Latitude Auroral Oval Through a Convection-Driven Equatorward Shift of Auroral Currents

The auroral oval, a luminous manifestation of solar wind–magnetosphere interaction, is typically confined to Earth’s polar regions. The geomagnetic superstorm of 10 May 2024, however, provides a clear case in which auroras expanded to extreme low magnetic latitudes. Through an analysis focusing on dusk-side auroras, combined with coordinated observations and magnetohydrodynamic simulations, we demonstrate that the primary cause was an extreme equatorward movement of both field-aligned currents and auroral electrojets. This systemic movement was driven by intense sunward plasma convection penetrating to unusually low latitudes. Specifically, these convection-driven auroral currents shifted equatorward, reaching south of 60° geomagnetic latitude, while the brightest auroral emissions extended to 50°. Furthermore, simulations indicate that a strong negative interplanetary magnetic field‘s y-component compressed the plasma sheet equatorward, which specifically enhanced the southward displacement of the dusk-side auroral oval in the Northern Hemisphere. Our findings establish a convection-driven mechanism for mid-latitude auroras during superstorms, providing a critical basis for forecasting these extreme space weather events.