资源环境科技发展态势分析平台

The field-aligned plasma drift in the equatorial ionosphere drives the interhemispheric transport of the ionospheric F region plasma between the Northern and Southern Hemispheres. We use the Communication/Navigation Outage Forecasting System satellite measurements, for the first time, to present the responses of the equatorial field-aligned drift during the 2009 sudden stratosphere warming (SSW). The observations show that the equatorial field-aligned drift presents a southward disturbance in the morning sector and a large northward disturbance in the afternoon sector and gradually shifts to later local time during the SSW. Further, this new finding of semidiurnal disturbance in field-aligned drift can well explain the hemispheric differences of the responses of the total electron content to the SSW. Based on the whole atmosphere model Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy, it is suggested that the meridional wind can contribute to the disturbance field-aligned drift. Our results give a new perspective for understanding the ionospheric perturbations during SSWs.