摘要 藉由Huang et al. [2005] 用TIEGCM模擬中、低緯度電離層風場與電場受地磁活動的影響的分析，發現磁暴發生時，由於極區受到能量侵入而產生加熱作用所產生的擾動風場會產生赤道向的電流，會在低緯度地區夜間累積電荷，電位最大發生的時間點會在午夜左右。因此在午夜之後可以發現東向擾動電場，並且可以發現極向擾動電場的產生在夜間。在磁暴結束之後，從模擬結果中得知子午向擾動電場會存在幾天的時間，相反的東西向電場會快速的消散並且恢復到安靜期的狀態。 在本篇論文是利用華衛一號所觀測到垂直於磁力線的子午向離子速度（V2m）與東西向離子速度（V2z），來研究磁暴發生時與磁暴結束之後磁赤道地區電離層電場變化。另外我們比對模式模擬結果與觀測資料看是否有一致的現象，來研究磁暴對磁赤道地區電離層電場的影響。

Abstract Model results of Huang et al. [2005], using the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM) to investigate the influence of geomagnetic activity on middle- and low-latitude thermospheric winds and ionospheric electric fields, indicate that that the equatorward current, produced by the disturbance winds, develops positive charge accumulation at low latitudes and maximizes in the premidnight sector. We may find the eastward perturbation electric field in the post-midnight sector and existence of poleward perturbation electric field at night time. After geomagnetic activity ceases, model results show that the meridional perturbation electric fields can last for many days in the post-recovery period, while the zonal perturbation electric fields decay more rapidly. In this thesis, two velocity components orthogonal to the geomagnetic field line, i.e., meridional component (V2m) and zonal component (V2z) are used to study the variations of equatorial iobospheric electric fields during and after the storm time. In addition, comparisons between model results and observational data have also been made.

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