English  |  正體中文  |  简体中文  |  全文笔数/总笔数 : 56570/90363 (63%)
造访人次 : 11885302      在线人数 : 49
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
搜寻范围 查询小技巧:
  • 您可在西文检索词汇前后加上"双引号",以获取较精准的检索结果
  • 若欲以作者姓名搜寻,建议至进阶搜寻限定作者字段,可获得较完整数据
  • 进阶搜寻

    jsp.display-item.identifier=請使用永久網址來引用或連結此文件: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/112423

    题名: Variations of topside ionospheric electron density near the dawn terminator in relation to geomagnetic activity
    作者: Sunny W.Y. Tam;Chien-Han Chen;Kaiti Wang
    关键词: solar zenith angle;penetration electric fields;auroral electron precipitation;neutral wind;dawnside ionosphere
    日期: 2017-11-27
    上传时间: 2017-12-19 02:10:33 (UTC+8)
    出版者: EDP Sciences
    摘要: A statistical study to determine the influence of geomagnetic disturbances on the ionosphere across the dawn terminator at subauroral and middle latitudes is performed, based on the vertical electron density profiles measured by the GPS Occultation Experiment aboard the FORMOSAT-3/COSMIC satellites from August 2006 to July 2009. Three ranges of solar zenith angles are adopted to characterize transitions between the pre- and post-dawn ionosphere. Results indicate opposing plasma density effects at the darkened and sunlit locations between 50° and 65° magnetic latitude (λm). The darkened topside ionosphere features density increases associated with geomagnetic activity, while density reductions mark its sunlit counterpart. The average electron peak density in the F2 region can increase by up to 44% in the darkened ionosphere and decrease by up to 20% in the sunlit ionosphere as Kp changes from 0–1 to 4–5. In the λm = 55°–65° range, the dominant contributors to the density perturbation are auroral electron precipitation for the darkened region and enhanced penetration electric fields for the sunlit region, with the transition occurring across the terminator local times. Dominance shifts first to electric fields at 50°–55°, then to aurora-induced neutral wind at 45°–50°, suggesting that during disturbed times electric fields seldom penetrate below λm = 50°. Findings presented in this statistical study should contribute to the study of space weather and the understanding of non-local influences of geomagnetic disturbances on topside dynamics.
    關聯: Journal of Space Weather and Space Climate, 7, A31, pp.1-20
    DOI: 10.1051/swsc/2017030
    显示于类别:[航空太空工程學系暨研究所] 期刊論文


    档案 描述 大小格式浏览次数
    Variations of topside ionospheric electron density near the dawn.pdf3155KbAdobe PDF27检视/开启



    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - 回馈