摘要: | 利用鹿林天文台全波段分色全天影像儀 (all-sky imager, ASI),配合地面全球定位系統 (Global Positioning System, GPS) 接收機、高頻都卜勒探測系統 (HF Doppler sounding system, DSS)、電離層探測儀 (Ionosonde),以及福爾摩沙衛星七號 (FORMOSAT-7/COSMIC-2, F7/C2) 掩星多種儀器,觀察2021年11月01日台灣地區大氣暉光亮暗帶與其伴隨之電漿泡。當全天影像儀觀測電離層大氣暉光經緯二維結構之同時,GPS接收機紀錄全電子含量(Total Electron Content, TEC)和TEC擾動指數(Rate of TEC Index, ROTI);DSS監測電離層都卜勒頻移;Ionosonde觀察電離圖;F7/C2掩星觀測電子濃度、全電子含量及閃爍指數廓線。結果顯示大氣暉光亮暗帶會分別對應TEC (ROTI) 之增減 (弱強)。暉光暗帶區域,都卜勒頻移劇烈頻散同時先增加後逐漸減少;電離圖出現虛高散狀F層。鹿林天文台全波段分色全天影像清楚顯示2021年11月01日夜間2000 LT至次日0200 LT之暉光亮暗帶東向漂移速度為60-100 m/s。此外,F7/C2掩星觀測顯示於暗帶地區,電子濃度與全電子含量(閃爍指數)會急遽減少(增強)。整體而言,暉光暗帶是為電漿濃度和全電子含量減少區域,伴生之電漿泡會引發都卜勒頻移和電離圖虛高嚴重擾亂,進而引發電波強烈相位擾動和振幅閃爍。 ;This study utilizes a full-band chromatic all-sky imager together with multi-instruments, including ground-based GNSS (Global Navigation Satellite System) receivers, Doppler Sounding Systems (DSSs), local ionosonde, and FORMOSAT-7/COSMIC-2 (F7/C2) TGRS (TriG GNSS Radio occultation System), to observe airglow depletions and plasma bubbles in Taiwan on 1 November 2021. While the Lulin all-sky imager observes airglow depletions, the GNSS receivers record the total electron content (TEC) and associated rate of TEC index (ROTI); DSSs register doppler frequency shifts; and F7/C2 observed electron density, TEC, and scintillation S4-index profiles accordingly. Results depict that when airglow emissions and depletions appear, TEC (ROTI) increases and decreases (decreases and increases), respectively. The airglow depletions yield horizontal drifts of about 60-100 m/s eastward from 2000 LT (local time), 1 November to 0200 LT, 2 November 2021. Moreover, F7/C2 profiles show that the electron density and TEC (S4-index) reduce (enhances) when airglow depletions appear. In general, airglow depletions are associate with plasma and TEC depletions, where the associated plasma bubbles result in significant frequency shift fluctuations and remarkable range spread-F layers, which further cause intense phase fluctuations and amplitude scintillations of GNSS signals. |