径向行星际磁场（radial IMF）是一种特殊的太阳风条件，其磁场指向是与太阳风速度平行。径向行星际磁场对应的磁场强度、太阳风速度、密度以及温度都比年平均值小。该项目利用我国极地科考站获取的高时间和空间分辨率极光观测数据，结合SuperDARN雷达网提供的极区电离层对流监测数据，旨在研究径向IMF对应的日侧极光的详细演化特征；极区电离层对流有关的关键参量的变化特征；电离层对流南北半球共轭观测现象对比。目的是获得径向IMF条件下日侧极光的规律性特征，以及这种特殊太阳风条件有关的极区电离层等离子体的动力学演化，以便更加客观地揭示径向IMF对磁层-电离层耦合系的影响效果。

The long-duration radial interplanetary magnetic field (IMF) events are unique phenomenon in the interplanetary space. The magnetic field of the Sun propagates with the solar wind because of the frozon-in condition. On average, typical values of all solar wind parameters for the radial IMF are lower and quieter than those of other IMF orientations. By using those high-temporal and spatial resolution optical aurora measurements obtained from Chinese Antarctic and Arctic scientific stations and simultaneous polar ionospheric convection observation deduced from SuperDARN high frequency radar data, fine structure of the dayside optical aurora and its evolution will be investigated under interplanetary condition of radial IMF. These main parameters, including pairs of the convection vortices, magnitude of the vortices and associated cross polar cap potential. Comparative study on interhemispheric polar ionospheric convection will also be studied. The main aim of this proposal are to obtain the conventional knowledge on dayside aurora associated with radial IMF, dynamical feature of the polar ionospheric convection for understanding magnetosphere-ionosphere coupling during such radial IMF.