台灣上空電離層E域頂層三公尺級電子密度不規則體：特性分析與研究;On the investigation of characteristics of 3-m field-aligned irregularities in upper E region of Taiwan

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Title:	台灣上空電離層E域頂層三公尺級電子密度不規則體：特性分析與研究;On the investigation of characteristics of 3-m field-aligned irregularities in upper E region of Taiwan
Authors:	林庭安;Lin,Ting-An
Contributors:	太空科學研究所
Keywords:	電離層;散塊E層;場延不規則體;中壢特高頻雷達;電離層探測儀;福衛三號
Date:	2014-07-24
Issue Date:	2014-10-15 14:37:30 (UTC+8)
Publisher:	國立中央大學
Abstract:	本篇論文利用中壢特高頻雷達2008 年2 月5 日、2009 年3 月1 日、2009年7 月19 日、2011 年3 月5 日、2012 年9 月23 日及2012 年10 月18 日等六天的觀測資料進行電離層E 域頂層不規則體與夜間散塊E 層不規則體的特性定量統計，分成頻譜特性、空間特性及動力行為三大部份，包含平均都卜勒速度、頻譜寬、回波功率、高度、厚度、東西向寬度、東西向漂移速度和夜間散塊E 層的下降速度，由分析結果可知E 域頂層回波具有與夜間散塊E 層回波不相同的特性。另經由干涉法分析得知除2009 年7 月19日外的E 域頂層回波皆為團狀電漿結構分布，而夜間散塊E 層皆呈層狀電漿結構分布。除特性統計外，使用HWM07 模式比較水平中性風場對E 域頂層回波及夜間散塊E 層回波的影響程度，發現一般適用於散塊E 層形成機制的風切理論較難解釋E 域頂層回波的形成原因。最後，使用福衛三號閃爍指數(S4)資料、電離層探測儀觀測之電離圖與中壢特高頻雷達的觀測結果進行比較分析，發現S4 指數峰值所在的高度及以動差法計算而得的平均高度皆與中壢雷達觀測的不規則體回波功率、頻譜寬峰值所在高度有差異。;In this thesis, we used totally 6 days (2008.Feb.05, 2009.Mar.01, 2009.Jul.19, 2011.Mar.05, 2012.Sep.23 and 2012.Oct.18) of Chung-Li VHF radar observations to analyze the spectral properties, spatial extents and kinematic behaviors of upper Es FAIs and normal Es FAIs. We found huge differences between the statistical results of upper Es FAIs and normal Es FAIs in terms of mean Doppler velocity, mean spectral width, echo power, average height, thickness (vertical extent), E-W extent and zonal trace velocity. We quantified the spatial extents of the echoes to differentiate layer-type and clump-type plasma structures. Besides statistical analyses, we have introduced HWM07 model to demonstrate the effects of wind shear to normal Es and upper Es. It is found that the relation between wind shear theory and the occurrence of upper Es remains unclear. As the final part of the thesis, we compared S4 index data of COSMIC and ionograms with the radar observations. From both radar data and ionograms, it is observed that the Es layer of the Es layer decreased through time. The height at which the peak Es echo power and the widest spectral width were observed is different from the height where the S4 index reached the maximum.
Appears in Collections:	[Graduate Institute of Space Science] Department of Earth Sciences

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