2004年11月一次磁暴期间全球电离层TEC扰动分析

利用全球分布的GPS原始观测数据提取的电离层总电子含量(TEC)分析了2004年11月6日至12日期间全球电离层暴的形态特点与发展过程．结果表明,11月8日磁暴主相期间电离层暴以大范围的强烈正暴为主,在11月10日的恢复相,Dst又一次降到最低值前后期间,电离层再次受到很强的扰动,大范围的正暴和负暴交替出现．这次磁暴期间夏季半球的负暴更加强烈,反映出负暴偏向于在夏季半球发生的季节变化特点．另外,磁暴期间,夜晚TEC值普遍比磁暴前的平静期要低,具体是什么机制导致还需要进一步收集数据和分析．

Analysis of Global Ionospheric TEC Disturbance During the Magnetic Storm in Nov. 2004

The characteristics and development of the ionospheric storm between Nov.6 and Nov. 12,2004 was studied using the total electron content (TEC) derived from GPS data observed by globally-distributed GPS stations under International GPS Service for Geodynamics (IGS).It was found that when magnetic storm was in its main phase on Nov.8,the ionospheric positive storm occurred over a large region of mid-and low latitude in the day time.And during the recovery phase on Nov.10,when Dst index reached its minimum,the global ionosphere was intensely disturbed and both positive and negative effects appeared.During this storm,negative effects appeared more intensely in the southern hemisphere (the summer hemisphere) than in the northern one,which is consistent with previous statistic results that negative storms have a proneness to appear in the summer hemisphere.It has been also observed that during the storm the value of night time TEC is low comparing the night TEC with no storm period,for which many mechanisms has been proposed. Because of the complex evolution process of ionospheric storm,more data including from other observation methods during other large ionospheric storms needs to be collected and analyzed.