极隙区是日地相互作用过程中重要的能量与物质传输通道。系统地研究极隙区粒子从磁鞘到电离层的传输过程，掌握极隙区电离层踪迹的动力学过程及其对热层大气的作用，对于理解日地相互作用和空间天气过程等具有重要科学价值。本项目基于对极隙区纬度南极中山站和北极黄河站自主的极光观测，结合不同高度卫星的协同探测，建立极隙区电离层的光学判定方法，研究各类太阳活动事件中极隙区投影的大小、位置和运动变化与特征；利用磁层、电离层卫星协同探测，研究极隙区粒子穿越磁层顶、沿磁力线加速及其电离层/热层沉降过程与特征；利用SuperDARN HF雷达、欧洲非相干散射雷达、Digisonde等电离层观测以及激光雷达、法布里-佩罗干涉仪和卫星观测等热层探测，研究极隙区电离层和热层的区域特征及其耦合过程。

Earth’s cusp is an important passage through which solar wind energy and particles can directly entry into the geo-space. A systematic study on cusp particles penetration through magnetopause and precipitating into the ionosphere, connecting with the dynamics of and coupling between the cusp ionosphere and thermosphere, would play crucial roles in better understanding the solar-terrestrial interaction and space weather. In this research, an optical algorithm of the cusp’s ionospheric projection is to be developed through the auroral observation at the Antarctic Zhongshan and Arctic Yellow River stations and satellite conjunction observation at different altitudes. The algorithm will be used to study cusp’s variation of size, location and movement with its ionospheric projection under different solar conditions. Using satellite conjunction observation with magnetosphere and ionosphere, some dynamic processes and characteristics of magnetosheath particles in Cup will be studied, such as to penetrate through the cusp magnetopause, to accelerate along the magnetic field lines, and to precipitate into the ionosphere/thermosphere in different solar events. Using ionospheric observation with SuperDARN HF radars, EISCAT incoherent radars, and Digisondes, and thermospheric observation with Lidars, Fabre-Perot interferometers and CHAMP satellite, we will study the regional characteristics of and coupling processes between the ionosphere and thermosphere electrically connecting to the magnetospheric cusps.