电离层TEC对GRB041227的响应

2004年12月27日世界时21时30分,一个非常强的γ射线暴扫过地球,它使得暴露在这次事件中的地球高层大气产生额外电离.在爆发期间,地球上多个甚低频(VLF)电波台站都同时观测到了电离层突然骚扰(SID)事件.对GOES卫星的X射线数据、ACE卫星的太阳风和行星际数据以及理论分析表明,地球上观测到的SID事件是由GRB041227引起的.另外,利用国际GPS服务网(IGS)提供的观测数据,采用相干求和的数据处理方法研究了电离层总电子含量(TEC)对这次γ射线暴的响应.结果表明,SGR1806-20产生的GRB041227对地球电离层产生了明显的影响.在爆发期间,平均电离层TEC有一定的增加,其最大增加值约0.04TECU(1TECU=10~(16)el/m~2),产生效果与一个C级或者低于C级的太阳耀斑相当.计算结果还表明了遥远的天体也能对地球的近地空间环境产生或多或少的影响.

Response of Total Electron Content of Terrestrial Ionosphere to GRB041227

On 27 December 2004,at 21:30UT,a extremely intense Gamma ray flare from the soft Gamma repeater SGR1806-20 hit earth,which resulted in the additional ion- ization of earth's upper atmosphere exposed to this great flare.During this burst,an obvious sudden ionospheric disturbances(SID)event was recorded by multi-stations of very low fre- quency(VLF)observations.The X ray data from GOES satellite and the solar wind and interplanetary magnetic field(IMF)data from ACE satellite and theoretical analysis proved that the observed SID events were induced by SGR 1806-20.By using coherent summation data processing method,the response of ionospheric total electron content(TEC)derived from global positioning system(GPS)observational data to this GRB is investigated.It is found that GRB041227 evidently affected ionosphere,and the peak increase of average TEC is about 0.04TECU(1TECU=10~(16)el/m~2),which is equivalent with that caused by C or below C class solar flare.In addition,the calculated results of this paper as well as the former study results from other authors show that the remote celestial bodies can also affect near earth space environment more or less.