本文利用福衛一號在離地600公里處軌道範圍涵蓋地理緯度南北緯35度之特性，觀測四個磁暴事件2000/07/15、2001/03/31、2003/1029、2003/11/20中低緯度電離層日夜兩側的反應。取四個事件前50日(DST>-50nT)當作平靜期的背景資料。將磁暴日的衛星軌跡大至分為日夜兩側，磁暴發生時，伴隨著行星際磁場的變化，北向的行星際磁場Bz會在日側形成西向電場，而南向的行星際磁場Bz會在日側形成東向電場，此一穿透電場的產生可能會使得中低緯度電離層發生變化。
衛星所酬載的電離層電漿電動效應儀所搜集的離子漂移速度、帶電粒子濃度，對照當地時間及磁緯度可以分別得到平靜期和磁暴期的E×B drifts速度及帶電粒子濃度的分佈。將磁暴期和平靜期的資料相互比較，我們可以發現磁暴時若有伴隨穿透電場效應，則日側中低緯度電離層帶電粒子濃度可能上升，夜側則下降。另外還觀測到磁暴期間從高緯區吹來的中性風也會使中低緯度電離層帶電粒子濃度上升。

The ROCSAT-1 satellite was launched into a circular orbit at about 600km altitude with an inclination of 35 degrees, with which the globale responses of four magnetic storm events occurred on 2000/07/15, 2001/03/31, 2003/1029, 2003/11/20, respectively, were analyzed in the mid- and low-latitude ionosphere. The data of 50 days before storm onset were taken to construct the background conditions. According to the satellite pathes of the storm events, a division for dayside and nightside can be roughly defined. The daytime penetration electric fields, eastward resulted from southward turning and westward from northward turning of the IMF Bz, enable the mid- and low- latitude ionosphere to change.
The variation of ion drifts and charge particle densities with the local time and the magnetic latitudes observed by the IPEA on board ROCSAT-1 may be used to build up the distribution of the E×B drifts and plasma densities for the quiet time and storm time conditions. In the observations, we find that the increases of the daytime ionospheric plasma densities may result from the eastward penetration electric field in the storm time; the densities decrease in the nighttime. Moreover, neutral wind blowing from the high latitudes may also cause the charged particle density of ionosphere in mid- and low-latitude to rise.

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