Field-Aligned Electrons in Polar Region Observed by Cluster on 30 September 2001
ZHANG Zi-Ying1**, SHI Jian-Kui1, CHENG Zheng-Wei1, Andrew Fazakerley2
1State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 2MSSL, University College London, UK
Abstract:The physical process in the Earth's polar region is very complex and still needs to be further studied. Using the data from Cluster satellite measurement, an analysis on field-aligned electrons in the mid-latitude cusp on 30 September 2001 has been performed. The satellite observed a down-flowing electron event in the low-latitude boundary and a sequential up-flowing electron event in the high-latitude boundary of the cusp region. The down-flowing electron had a velocity as high as 500 km/s and a flux of 2.0×109 cm?2?s?1. The up-flowing electron had a velocity up to 1200 km/s and a flux of 4.9×109 cm?2?s?1. Both the velocity and the flux observed in this event are the maximum values of the up-flowing electrons observed by all satellites to date. The electron is the main contributor for the field-aligned current in this event. The physical mechanism is also discussed. The down-flowing electron in the low-latitude boundary of the cusp region may result from solar wind injecting during the southward IMF, and the up-flowing electrons in the high-latitude boundary of cusp may result from mirroring of the solar wind, or from the ionospheric up-flowing electrons which have been accelerated.
. [J]. 中国物理快报, 2012, 29(9): 99401-099401.
ZHANG Zi-Ying, SHI Jian-Kui, CHENG Zheng-Wei, Andrew Fazakerley. Field-Aligned Electrons in Polar Region Observed by Cluster on 30 September 2001. Chin. Phys. Lett., 2012, 29(9): 99401-099401.