本論文利用太陽同步衛星DEMETER上的兩種酬載同時同地量測電子濃度、電子溫度及哨波3種太空參數，進行中緯度槽與電漿層頂的觀測。2006–2009年研究期間，共超過13,000筆由電子濃度、電子溫度觀測之中緯度槽，以及哨波量測的電漿層頂資料。除能個別對中緯度槽或電漿層頂位置進行研究，更能精準比較兩者位置對經度、太陽活動、季節與地磁擾動的變化與差異，了解中緯度槽或電漿層頂間的關係，克服過去僅能以同時卻無法同地，或是同地卻無法同時觀測進行比較的限制。在夜間2230LT (Local time, 當地時間)觀測結果，電漿層頂位於較中緯度槽緯度低的赤道側。電漿層頂對太陽活動響應較明顯，當太陽活動變大，電漿層頂位置會往低緯度赤道方向移動1.0°–1.2°。中緯度槽則在季節變化上的響應較明顯，當由冬季轉至夏季時，中緯度槽位置會往高緯度極區方向移動1.7°–2.5°。中緯度槽與電漿層頂在地磁擾動時會同時往低緯度移動，中緯度槽移動速度大於電漿層頂，當地磁擾動Kp≥6-時，兩者位置會相同並開始互換，出現中緯度槽在電漿層頂赤道側的現象。在日間1030LT無法觀測到中緯度槽，但電漿層頂仍明顯可觀測。日側電漿層頂位置大致上較夜側的緯度低，對太陽活動與地磁擾動的變化與夜側電漿層頂相似。;This paper concurrently investigates the mid-latitude trough and the plasmapause positions in the ionosphere by co-located measurements of the electron density, electron temperature, and whistler count probed by DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite in the daytime/nighttime at 1030/2230 LT during the 4-year period of 2006–2009. More than 13000 DEMETER orbits of the electron density and the electron temperature are used to search the trough position, while the same amount of the whistler count is employed to determine the plasmapause position at the satellite altitude. At nighttime, the plasmapause is more sensitive to solar activity, which moves equatorward 1.0°–1.2° form the low to high solar activity of the study period. On the other hand, the mid-latitude trough is more sensitive to seasonal variation, which shifts poleward 1.7°–2.5° from the Winter to Summer in the study period. The mid-latitude trough usually appears in the poleward side of the plasmapause during the study period. Both of the mid-latitude trough and the plasmapause move equatorward during the magnetic disturbed condition. For the magnetic disturbed Kp≥6-, the mid-latitude trough can appear in the equatorward side of the plasmapause. At the daytime, the trough cannot be clearly allocated, while the plasmapause is observable. The daytime plasmapause mainly appears in the equatorward side of the nighttime one. Its responses to the solar activity and to the magnetic disturbed are similar to the nighttime plasmapause.
