Abstract
We have studied 172 field-aligned currents (FACs) cases observed by the ClusterII satellites when they crossed the plasma sheet boundary layer (PSBL) in the magnetotail from July to October 2001. We mainly analyzed the relationship between the characteristic of FACs at the PSBL in magnetotail and the Kp index. The main results indicated the followings: 1) In the different geomagnetic activity levels, the relative occurrence of FACs in PSBL increased monotonically with geomagnetic activity. 2) The density of FACs in PSBL increased monotonically with Kp index. In the storm main phase, the density of FACs increased dramatically, the maximum FACs approximately equaled 19.05 nA m−2 while Kp equaled 5. 3) The variation of FACs density in PSBL was consistent with the variation of the Kp index. However, when AE<800 nT, FACs density in PSBL increased with increasing AE, and when AE>800 nT, it decreased with increasing AE. Therefore, our results suggested that the FACs density in PSBL had a closer correlation with Kp index.
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Cheng, Z., Shi, J., Zhang, T. et al. The relations between density of FACs in the plasma sheet boundary layers and Kp index. Sci. China Technol. Sci. 54, 2987–2992 (2011). https://doi.org/10.1007/s11431-011-4545-3
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DOI: https://doi.org/10.1007/s11431-011-4545-3