文献类型：期刊文献

英文题名：South - North Hemispheric Asymmetry of the FAE Distribution Around the Cusp Region: Cluster Observation

作者：Shi, Jiankui[1,2,3];Zhang, Ziying[4];Torkar, Klaus[5];Cheng, Zhengwei[1];Escoubet, Phillipe[6];Farzakeley, Andrew[7];Dunlop, Malcolm[8];Carr, Chris[9]

第一作者：Shi, Jiankui

通讯作者：Zhang, ZY[1]

机构：[1]Chinese Acad Sci, Natl Space Sci Ctr, State Key Lab Space Weather, Beijing, Peoples R China;[2]Univ Chinese Acad Sci, Sch Astron, Beijing, Peoples R China;[3]Univ Chinese Acad Sci, Sch Space Sci, Beijing, Peoples R China;[4]Beijing Union Univ, Coll Appl Arts & Sci, Beijing, Peoples R China;[5]Austrian Acad Sci, Space Res Inst, Graz, Austria;[6]ESA ESTEC, Sci Support Off, Noordwijk, Netherlands;[7]UCL, MSSL, London, England;[8]Rutherford Appleton Lab, SSTD, Didcot, Oxon, England;[9]Imperial Coll London, London, England

第一机构：Chinese Acad Sci, Natl Space Sci Ctr, State Key Lab Space Weather, Beijing, Peoples R China

通讯机构：[1]corresponding author), Beijing Union Univ, Coll Appl Arts & Sci, Beijing, Peoples R China.|[114172]北京联合大学应用文理学院;[11417]北京联合大学;

年份：2019

卷号：124

期号：7

起止页码：5342-5352

外文期刊名：JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS

收录：;Scopus(收录号：2-s2.0-85069828984);WOS:【SCI-EXPANDED(收录号:WOS:000482985600027)】；

基金：This research was supported by the National Natural Science Foundation of China (41674145 and 41874172), the General Project of Science and Technology Program of Beijing Education Commission (KM201911417015), and the Specialized Research Fund for State Key Laboratory in China. We thank the PEACE and FGM instrument teams and Cluster Science Archive system providing the data on the website (www.cosmos.esa.int/web/csa).

语种：英文

外文关键词：FAE events; cusp region; north-south asymmetry; Cluster observation

摘要：Cluster data from late July to early October were used to study the distribution of field-aligned electron (FAE) events around the two cusps. An FAE event was defined as electron parallel flux >3 x 10(8) (cm(2) s)(-1). The total number of FAE events around the two cusps was basically identical, but downward FAE events prevailed in the south and upward FAE events in the north. In the southern cusp, the peak of the FAE events distribution versus altitude was about 1.3 R-E higher and the peak of the FAE events distribution versus invariant latitude (ILAT) was about 4 degrees ILAT lower. Only the downward FAEs around the southern cusp had a second ILAT peak, which was located about 11 degrees higher than the main peak. The normalized number of FAEs showed nearly the same features as the unnormalized number of the FAEs events. These results indicated a north-south asymmetry of the FAE distribution around the two cusps. Some causes for the asymmetry are discussed, the main ones being the asymmetry of the magnetospheric configuration resulting from geomagnetic dipolar tilt and solar wind flows, the interplanetary magnetic field asymmetry related to the magnetosphere, and the difference of ionospheric conductivity in the two hemispheres. Various solar wind-magnetosphere interaction processes, such as quasi-viscous interaction and reconnection, are responsible for the asymmetry, too. The second distribution peak (at higher ILAT) of the downward FAE events around the southern cusp corresponded to high solar wind speed and may be associated with the northward interplanetary magnetic field B-z field-aligned current at low altitude. This requires further studies, however.