Convection driven field-aligned currents and auroral electrojets during continuous strong substorms

The sudden increase in high latitude ionospheric currents and two-cell convection are both important elements during geomagnetic substorms. Although simulations and statistical analyses suggest a relationship between the two phenomena in magnetosphere-ionosphere coupling, the spatiotemporal correlation of their evolution in observation has not been clearly demonstrated. Here we select multiple continuous strong substorms under a strong geomagnetic storm as a case to effectively reveal the synchronous evolution of field-aligned currents (FACs) and auroral electrojets with convection. The observation results indicate that the bidirectional convection activity between the dayside and nightside-driven affects to multiple "V" shaped movements of dawnside FACs on magnetic local time (MLT), and continuously changes the magnetic latitude (MLAT) difference of nightside FACs. Meanwhile, the dawn-dusk asymmetry of convection further affects the different evolutionary characteristics of the east-westward electrojets. These results demonstrate a strong coupling between convection and ionospheric currents, underscoring the pivotal role of convection in the progression of substorm phases.