Simultaneous transients in the auroral zone and the equator as observed with SuperDARN and magnetometers: A correlation with equatorial counter electrojet (CEJ) event

摘要

An equatorial counter electrojet (CEJ) event characterized by a large amplitude (～150 nT) and a short duration (～15 min) magnetic disturbance occurred in the dayside region at 0053 UT, 23 October 1994. This event was detected by the ground magnetometers along the dayside dip-equator. The CEJ current, with local westward ionospheric currents, was located to the north of the normal eastward current (equatorial electrojet: EEJ) that existed prior to the CEJ event. Simultaneously with the occurrence of the CEJ event, an enhanced plasma convection with very high velocity (～2000 m/s) was observed by SuperDARN in the dusk sector of the auroral zone. These simultaneous occurrences in the auroral zone and at the equator may suggest that such an impulsive CEJ event could be inteipreted as a violation of the shielding of the high-latitude potential pattern.