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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/5309


    Title: 電離層閃爍與極光區電噴流和下降帶電粒子之相關性;Ionosphere Scintillation in Response to Auroral Electrojet and Field-aligned Precipitating Charged Particles
    Authors: 戴淵竣;Yuan-June Tai
    Contributors: 太空科學研究所
    Keywords: 下降帶電粒子;極光區電噴流;電離層閃爍;Ionosphere Scintillation;Auroral Electrojet;Field-aligned Precipitating Charged Particles
    Date: 2009-06-30
    Issue Date: 2009-09-22 09:49:17 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 本篇論文利用福衛三號衛星群(FORMOSAT-3/COSMIC)所提供的GPS L1電波閃爍指標S4資料及DMSP衛星所提供之極光區場沿下降電子資料,以探討地磁擾動(Kp)、極光區電噴流(AE)、及極光區下降高能電子的分佈對於極光區電離層閃爍的影響。我們選擇2007年的冬季、夏季及5月23日磁暴期間之資料做分析。統計分析的結果發現:(1)S4的強度在地方時對磁緯度座標中(MLT-MLAT)的分佈與極光區下降粒子(30eV-30keV)的分佈相同,不論冬或夏,閃爍現象在黃昏到午夜前最為明顯,但夏季時閃爍強度一般比冬季的強;(2)當Kp增強時,強閃爍分佈區域變寬;(3)閃爍強度分佈的變化隨AE的變化最為敏銳,當AE增強時,強閃爍區域向高低緯延伸,從黃昏到午夜過後都可見到強閃爍發生。進一步比較5月23日磁暴擴張期(06-14 UT)時的S4強度分佈與場沿下降(1-10keV)電子分佈我們確定強電離層閃爍的發生和變化受到極光區下降高能電子的分佈與變化的影響很大。 In this thesis we use the S4 data of GPS L1 scintillations received by FORMOSAT-3/COSMIC satellites and the field-aligned electron precipitation data measured by the DMSP satellites in auroral region to study the distribution of scintillation events at high latitude ionosphere. We discuss how the changes of geomagnetic field disturbance (specified by Kp), auroral electrojet current (represented by AE) and energetic precipitating electron flux, will affect the spatial distribution as well as the intensity level of ionospheric scintillations. We choose the data of the 2007 summer and winter, and of the highlight period of a magnetic storm on May 23 for analyses. The main results of the analysis are summarized as follows. From statistical analyses we found: (1) the morphology of the intensity distribution of scintillation (represented by S4 index) is approximately coincident with that of auroral electron (30eV ~30keV) precipitation flux in the magnetic local time versus magnetic latitude coordinate frame (MLT-MLAT). The scintillation phenomenon is most pronounced in the local time sector from sunset to the midnight regardless of seasons. However the strength of scintillation in the summer is generally stronger than that in the winter. (2) As Kp increases, strong scintillation events span wider MLT-MLAT region. (3)The distribution and intensity of scintillation respond most sensitively to the change of AE. As AE increases the morphology of strong scintillations expands to both high and low latitudes. Strong scintillation can be seen from the sunset to the post midnight hours. Furthermore, by comparison of the simultaneous measurements of S4 with energetic (1-10keV) precipitating electrons during the expansion phase (06-14 UT) of the May 23 storm we found that the occurrence and variations of strong scintillation events are greatly affected by the distribution and dynamics of auroral precipitating electrons.
    Appears in Collections:[太空科學研究所 ] 博碩士論文

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