空间科学学报2024，Vol.44Issue(3)：446-457,12.DOI:10.11728/cjss2024.03.2023-0070
基于范艾伦卫星观测数据的地球辐射带电子能谱分布的统计分析
Statistical Analysis of Distributions of Electron Energy Spectra in the Earth's Radiation Belts Based on Van Allen Probes Observations
摘要
Abstract
The characteristics of energy spectra distributions of radiation belt electrons can help re-veal the dominant physical mechanism behind the dynamics of the radiation belt.In this study,the tem-poral and spatial distribution characteristics of energy spectra of energetic electrons are statistically ana-lyzed using the measurements from Van Allen probes during 2014-2018.The results show that most of the electron spectra in the radiation belt can be classified into three types:exponential,power-law and reversed spectra.The exponential spectra dominate in the outer radiation belt outside the plasmapause.The power-law spectra usually occur at higher L values and move to lower L values during geomagnetic storms.During quiet geomagnetic activity periods,the power-law energy spectra stay at the high L with longer time and higher proportion.The reversed energy spectra dominate at L>2.5 inside the plasmas-phere.As the increase of plasmapause locations,more reversed energy spectra occur while the propor-tion of the exponential energy spectra decreases.During long-term quiet periods,electron fluxes near the peak of the reversed energy spectra(about 2 MeV)are relatively low to form obvious reversed spectral.The results also show that the peak location of reversed energy spectra is about 2 L inside the plasma-pause while the peak location of exponential energy spectra is about 1.5 L outside the plasmapause.Ap-pearances of power-law energy spectra are related to substorm injections of electrons.Stronger magnetic storms produce wider L ranges where reversed energy spectra are replaced by exponential spectra.Dur-ing quiet times,exponential energy spectra inside the plasmapause are replaced by reversed energy spec-tra due to pitch angle scattering produced by plasmaspheric hiss waves.关键词
辐射带/电子能谱/范艾伦探测器/地磁活动/等离子体层层顶Key words
Radiation belts/Electron energy spectra/Van Allen Probes/Geomagnetic activity/Plasmapause分类
天文与地球科学引用本文复制引用
王建行,项正,马新,郭德宇,董俊虎,刘阳希子,胡景乐,倪彬彬..基于范艾伦卫星观测数据的地球辐射带电子能谱分布的统计分析[J].空间科学学报,2024,44(3):446-457,12.基金项目
国家自然科学基金项目(42025404,42188101,42174190),国家重点研发计划基金项目(2022YFF0503700),中国科学院战略性先导科技专项(B类)(XDB41000000)和民用航天技术预先研究项目(D020308,D020104)共同资助 （42025404,42188101,42174190）
