Occurrence of geomagnetic storms ( i . e . severe distortion of geomagnetic field of the earth ) can induce electric current in oil pipelines and electric cables 对输电系统及输油管的影响地磁暴（即地球磁场急速变形）会使输油管及电缆产生电流。
On the ground , telescopes and optical instruments are used to record the number of sun spots , as well as to observe aurora , which provide evidence of geomagnetic storms 在地面上的观测，主要利用望远镜及光学仪器去记录太阳黑子的数目，而极光的观测则能提供地磁暴出现的证据。
On the ground , telescopes and optical instruments are used to record the number of sun spots , as well as to observe aurora , which provide evidence of geomagnetic storms 在地面上的观测，主要利用望远镜及光学仪器去记录太阳黑子的数目，而极光的观测则能提供地磁暴出现的证据。
It is the very reason that many scientists try to make the prediction of geomagnetic storms by analyzing gcrs variation properties before the commencement of a geomagnetic storm 正是由于这个特性，国际上很多科学家试图利用磁暴前银河宇宙线强度变化的先兆特征来进行地磁暴预报。
We also made a statistical study on precursors appeared in gcrs before major and large geomagnetic storms only by using the two cusp stations " nm data obtained at mcmurdo and thule 对大磁暴前银河宇宙线强度的变化和各向异性进行的统计分析分析表明，银河宇宙线强度在磁暴前是有先兆的。
Denver - the most powerful geomagnetic storm possible walloped the earth early wednesday , knocking out some airline communications but apparently causing no large power outages or other major problems 丹佛最强烈的太阳磁暴于本周三开始袭击地球，并对某些航空通讯联系产生了干扰，但没有出现大规模电力供应中断或其他重大问题。
The statistical results show that there are about 66 . 7 % geomagnetic storms with precursors in gcrs . we can roughly judge the cmes " direction when passing through the earth by using the two nm station data 其先兆特征为宇宙线强度的增加、减少和各向异性有较大的提高，分析结果表明采用这种方法进行分析，约66 . 7的大磁暴前有先兆。
The field forms a protective shell called magnetosphere that has a radius around 10 times that of the solid earth . but strong eruptions on the solar surface can seriously distort this shell , creating geomagnetic storms 地球磁场形成一个大小约地球直径十倍称为磁层的保护壳，当太阳表面出现猛烈的爆发，便会严重扭曲这个保护壳，形成磁暴。
The ocrs intensity with the periods of 32 - 64 hours increased remarkably for those events that ocrs intensity decreased before the geomagnetic storms , while the intensity of ocrs with the periods shorter than 24 - hour are not obvious 对于磁暴前银河宇宙线强度减弱的事件，如1982年7月事件，周期为32 ? ? 64小时的信号幅度有较明显的增强，而周期低于24小时的信号变化非常不明显。
Because catastrophic space weather events occur in general very suddenly , such as geomagnetic storms with sudden commencements . forbush decrease ( fds ) in ocrs intensity is also a kind of sudden event . the properties of these sudden events " are very evident 山ttsh下降也是全球范围内银河宇宙线强度的突然下降，这是cme到达地球后对全球台站记录的宇宙线强度造成突然的影响，这些突发事件其突发特征非常明显。
