Role of electromagnetic coupling between mid-latitude ionosphere and inner magnetosphere during geomagnetic disturbances.

利用全球磁强计网络和SuperDARN雷达的数据，我们发现在亚暴扩展阶段，过屏蔽电场与对流电场一起发展。根据高频多普勒测量，中纬度地区的过屏蔽电场为2 mV/m，与风暴时的对流电场相当。结果表明，过屏蔽电场在中赤道地区的地磁扰动和电离层扰动中起着重要作用，并对磁层扰动的增长/衰减有贡献。

We showed that the overshielding electric field develops together with the convection electric field during the substorm expansion phase by using data from global magnetometer networks and SuperDARN radars. Based on the HF Doppler measurements, the overshielding electric field at mid latitude was found to be 2 mV/m, comparable tothe storm time convection electric field. Our results suggest that the overshielding electric field plays an important role in the geomagnetic and ionospheric disturbances at mid-equatorial latitudes and would contribute to the growth/decay of magnetospheric disturbances.