Bidirectional electron conic observations for photoelectrons in the Martian ionosphere

作     者：YuTian Cao Jun Cui BinBin Ni XiaoShu Wu Qiong Luo ZhaoGuo He YuTian Cao;Jun Cui;BinBin Ni;XiaoShu Wu;Qiong Luo;ZhaoGuo He

作者机构：Key Laboratory of Lunar and Deep Space ExplorationNational Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China School of Astronomy and Space SciencesUniversity of Chinese Academy of SciencesBeijing 100049China School of Atmospheric SciencesSun Yat-sen UniversityZhuhaiGuangdong 519082China Center for Excellence in Comparative PlanetologyChinese Academy of SciencesHefei 230026China Department of Space PhysicsSchool of Electronic InformationWuhan UniversityWuhan 430072China 

出 版 物：《Earth and Planetary Physics》 (地球与行星物理（英文版）)

年 卷 期：2020年第4卷第4期

页      面：403-407页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported by the B-type Strategic Priority Program No.XDB4100000 funded by the Chinese Academy of Sciences and the pre-research projects on Civil Aerospace Technologies No.D020105 and D020104 funded by China’s National Space Administration the National Natural Science Foundation of China through grants 41525015,41774186,and 41904154 

主　　题：Martian ionosphere photoelectron pitch angle distribution 

摘      要：Electron pitch angle distributions similar to bidirectional electron conics(BECs)have been reported at Mars in previous studies based on analyses of Mars Global Surveyor *** distribution,also termed“butterflydistribution,presents a local minimum flux at 90°and a maximum flux before reaching the local loss *** studies have focused on 115 eV electrons that were produced mainly via solar wind electron impact *** using Solar Wind Electron Analyzer measurements made onboard the Mars Atmosphere and Volatile Evolution spacecraft,we identify 513 BEC events for 19-55 eV photoelectrons that were generated via photoionization ***,we are investigating electrons observed in regions well away from their source regions,to be distinguished from 115 eV electrons observed and produced in the same *** investigate the spatial distribution of the 19-55 eV BECs,revealing that they are more likely observed on the nightside as well as near strong crustal magnetic *** propose that the 19-55 eV photoelectron BECs are formed due to day-to-night transport and the magnetic mirror effect of photoelectrons moving along cross-terminator closed magnetic field lines.