日食發生時，月球的影子相當於以超音速掠過地球表面，太陽輻射受到遮蔽導致地球大氣急速冷卻，劇烈暫態改變導致聲重波的產生，進而引發電離層擾動。本論文利用福爾摩沙衛星三號(FORMOSAT-3/COSMIC, F3/C)掩星觀測之電離層電子濃度垂直剖線，研究2009-2010年4個日食事件(2009/01/26, 2009/07/22, 2010/01/15, 2010/07/11)引發的電離層電子濃度變化和其垂直方向之擾動。整體而言，日食天的電離層電子濃度呈現減少之趨勢。利用希爾伯黃轉換(Hilbert-Huang Transform)計算電離層電子濃度剖線的瞬時頻率和振幅，以探討日食引發的擾動。結果顯示，電離層擾動於波數0.1-0.3 km-1(波長為3-10 km)顯著增強。本論文研究展示福衛三號掩星觀測技術可以有效探測電離層電子濃度垂直擾動特性。 This study examines wavy structures observed in the electron density profiles derived by GPS radio occultation experiment (GOX) on board FORMOSAT?3/COSMIC (F3/C) satellites during the solar eclipses of 2009-2010. F3/C electron density profiles observed before, during, and after the solar eclipses are used to find the disturbances in the vertical direction. We apply Hilbert–Huang transform to compute the instantaneous frequencies and amplitudes at every point of the decomposed intrinsic mode functions in the F3/C electron density profiles. The analysis show that numerous waves have been induced by the moon shadow during the eclipse periods.
