許多觀測顯示電離層低地磁緯度之赤道離化異常(equatorial ionization anomaly, EIA)存在季節變化。本論文分析1997到2005年間亞洲地區120°E之全球定位系統(Global Positioning System, GPS)衛星地面接收資料，研究南北半球全電子含量(total electron content, TEC)之EIA變化。同時分析環太平洋地磁觀測網資料，探討赤道電噴流(equatorial electrojet, EEJ)對TEC之EIA變化的影響。結果顯示，南北兩半球EIA和EEJ具有季節變化。EEJ峰值與EIA峰值之間存在有1.5-3小時的時間差，而此時間差亦存在有季節變化。EEJ對EIA強度和南北兩峰距離有明顯地線性關係。兩者之相關係數(correlation coefficient)約為0.52，但其季節與太陽活動效應並不顯著。 Many studies show seasonal variations of equatorial ionization anomaly (EIA). In this thesis, the ionospheric total electron content (TEC) in the Asian sector derived from measurements of ground-based receivers of the global positioning system (GPS) is employed to investigate the EIA variations during 1997-2005. In addition, magnetometer data from the Circum-pan Pacific Magnetometer Network (CPMN) are used to study the EIA variations associated with the equatorial electrojet (EEJ). It is found in both the northern and southern hemispheres that the EIA crests manifest remarkable seasonal variations. The EIA maxima lag those of the EEJ by about 1.5-3 hours. The results reveal the time delay of both hemispheres to be asymmetry and vary with seasons. There are obvious relations between the intensity of EEJ and EIA as well as distance between the two crests. The associated correlation coefficients are about 0.52. However, no obvious seasonal and solar activity effects are found between the two observations.
