English  |  正體中文  |  简体中文  |  Items with full text/Total items : 66984/66984 (100%)
Visitors : 23032421      Online Users : 151
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version


    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/50381


    Title: Longitudinal development of low-latitude ionospheric irregularities during the geomagnetic storms of July 2004
    Authors: Li,GZ;Ning,BQ;Hu,LH;Liu,LB;Yue,XA;Wan,WX;Zhao,BQ;Igarashi,K;Kubota,M;Otsuka,Y;Xu,JS;Liu,JY
    Contributors: 太空科學研究所
    Keywords: EQUATORIAL SPREAD F;PLASMA BUBBLES;ELECTRIC-FIELDS;MIDLATITUDE IONOSPHERE;PHASE FLUCTUATIONS;REGION;DRIFT;SCINTILLATIONS;EVOLUTION;GPS
    Date: 2010
    Issue Date: 2012-03-27 17:30:29 (UTC+8)
    Publisher: 國立中央大學
    Abstract: During the period 22-28 July 2004, three geomagnetic storms occurred due to a sequence of coronal mass ejections. In this paper we present and discuss the ionospheric observations from a set of in situ satellites and ground-based GPS total electron content and scintillation receivers, a VHF radar, and two chains of ionosondes (similar to 300 degrees E and similar to 120 degrees E, respectively) that provide the evolutionary characteristics of equatorial and low-latitude ionospheric irregularities versus longitude during these storm periods. It is found that the irregularities occurred over a wide longitudinal range, extending from around 300 degrees E to 120 degrees E on storm days 25 and 27 July 2004. On 25 July plasma bubbles (PBs) began premidnight in America and postmidnight in Southeast Asia. On 27 July the occurrence of irregularities followed the sunset terminator and was observed sequentially after sunset from American to Southeast Asian longitudes. Past studies have reported that storm-time low-latitude ionospheric irregularities are mostly confined to a narrower longitude range, <90 degrees, after sunset hours and are associated with the prompt penetration of eastward electric fields (PPEFs) into low latitudes. In June solstice months the occurrence of range-type spread F or PBs is very low in Southeast Asian and South American sectors. In contrast, the present results indicate that geomagnetic storms triggered the wide longitudinal development of PBs. In the American sector this was probably due to the effects of PPEFs on both storm days. However, in the Southeast Asian sector the PBs on the 2 days probably arose from disturbance dynamo electric field (DDEF), PPEF, and gravity wave seeding effects. This study further shows that under complex storm conditions, besides the long duration or multiple penetrations, the combined effects of PPEFs and DDEFs could result in a wide longitude extent of ionospheric irregularities at times.
    Relation: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
    Appears in Collections:[太空科學研究所 ] 期刊論文

    Files in This Item:

    File Description SizeFormat
    index.html0KbHTML306View/Open


    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback  - 隱私權政策聲明