电离层TEC对小耀斑的响应  

The Response of Ionospheric TEC to Small and Faint Solar Flares

作　　者：黄文耿[1] 古士芬[1] 陈艳红[1] 马冠一[1] 沈华[1] 

机构地区：[1]中国科学院空间科学与应用研究中心,北京100080

出　　处：《天文学报》2006年第2期212-217,共6页Acta Astronomica Sinica

基　　金：中国科学院知识创新项目(KGCX2-SW-408)

摘　　要：利用国际GPS观测网(IGS)提供的多个台站的观测数据,分析了M级别以下的小、暗太阳耀斑对向阳面电离层TEC的影响．利用传统分析方法的结果表明,从单条视线(LOS)观测数据得到的电离层TEC及其时间变化率曲线来看,由于它们的波动水平和正常情况下的背景电离层变化相当,使此类小耀斑的信息完全淹没在背景噪声中,不能够显示和分辨出耀斑的发生．利用相干求和的数据处理方法,选用向阳面18个GPS台站的观测数据研究了一次C级SF耀斑引起的电离层TEC增加,结果发现,这种方法能有效地消除背景电离层变化噪声,电离层对耀斑的响应非常清楚和明显,这通常只能在X级别的大耀斑中看到．和GOES卫星X射线数据相比,电离层TEC变化的时间特征和耀斑爆发的开始、最大和结束时间均有很好的符合,其最大平均TEC增量在0．1TECU以下,和X级别的大耀斑相比有一个或多个量级上的差别．Using GPS observational data of multi-sites provided by International GPS Service （IGS）, the effect of below M-class small and faint solar flares on ionospheric total electron content （TEC） of sunlit hemisphere were analyzed. By traditional method, the results show that one cannot see and distinguish this typical flare occurred from curves for TEC and its change rate with time obtained by single line of sight （LOS） between receiver on the ground and GPS satellite, because their fluctuation levels are comparable with normal ionospheric variations, which make flare information be immerged in background noise. A data processing method name by coherent summation was used to investigate ionospheric TEC enhancement caused by a small and faint C-class SF solar flare derived from 18 GPS stations data （which is composed of more than 90 LOS at any time during flare）. It is found that this method can substantially eliminate background ionospheric TEC variation ＂noise＂, and ionospheric response to flare is very clear and obvious by this method, which can usually only be seen in big flares. By comparison, the time characteristic of TEC variation is in good agreement with X-ray data from GOES satellite in start, peak and end time of flare occurred, and the maximum enhancement of average TEC is below 0.1 TECU, which is about one or more orders smaller than that caused by X-class large solar flares.

关 键 词：天体测量学:GPS 总电子含量(TEC) 

分 类 号：P123[天文地球—天体测量]