From Nov. 6 to 10, 2004, a large number of solar events occurred, which triggered many solar flares and coronal mass ejections (CMEs). These CMEs caused two large geomagnetic storms and continuous energy proton events...From Nov. 6 to 10, 2004, a large number of solar events occurred, which triggered many solar flares and coronal mass ejections (CMEs). These CMEs caused two large geomagnetic storms and continuous energy proton events. During this period, one large positive ionospheric storm happened over the East-Asian region on Nov. 8, 2004. On Nov. 10, 2004, a strong spread-F was observed by the ionosonde located in the mid-latitude region of East China and Japan, and the ionospheric fluctuation over the ionosonde stations derived from GPS observation was also obvious. In this report, the characteristics of the spatial distribution of the ionosphere fluctuation and its temporal evolution are studied using the parameter of the rate of total electron content (ROT) derived from dual-frequency GPS measurement. Strong fluctuating activity of the ionosphere was found over the mid-latitude region in the southern and northern hemispheres between longitudes of 100°E and 180°E during the magnetic storm period on Nov. 10, 2004, and a regular movement of the disturbing region was observed. In the end, the reason of the ionospheric fluctuation during this magnetic storm is analyzed.展开更多
文摘以2006年12月13日射电爆发事件为例,利用国际GNSS服务(international GNSS service,IGS)观测台网数据,结合L波段太阳射电流量和幅度闪烁指数监测数据,研究了向阳面地基台站对这次射电暴的响应.重点分析了我国境内几个典型地区台站载噪比的变化特征,并评估此次事件对不同地区GNSS服务和定位精度的影响程度.结果表明,太阳射电暴期间:1)GNSS信号受到严重干扰,几乎所有向阳面IGS台站都受到影响,影响程度呈现出明显的随太阳入射角变化特征;2)此次事件造成多个IGS台站锁定卫星数目小于4颗,大面积连续性失锁、间歇性失锁和导航信号完全中断现象发生;3)中国境内多个台站的定位误差显著增加,伪距单点定位误差高达40~60m,精密单点定位(precise point positioning,PPP)误差达到2m左右,一些台站发生短时定位服务中断;4)这次事件给日下点附近的台站造成非常严重的影响,PPP误差超过10m,而且还出现长达约10min的定位服务中断.文中结果能为第三代北斗导航卫星系统在评估空间天气威胁方面提供借鉴和参考.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41174134 and 40904036)the National Basic Research Program of China ("973" Project) (Grant No. 2011CB811405)the State Key Laboratory of Space Weather
文摘From Nov. 6 to 10, 2004, a large number of solar events occurred, which triggered many solar flares and coronal mass ejections (CMEs). These CMEs caused two large geomagnetic storms and continuous energy proton events. During this period, one large positive ionospheric storm happened over the East-Asian region on Nov. 8, 2004. On Nov. 10, 2004, a strong spread-F was observed by the ionosonde located in the mid-latitude region of East China and Japan, and the ionospheric fluctuation over the ionosonde stations derived from GPS observation was also obvious. In this report, the characteristics of the spatial distribution of the ionosphere fluctuation and its temporal evolution are studied using the parameter of the rate of total electron content (ROT) derived from dual-frequency GPS measurement. Strong fluctuating activity of the ionosphere was found over the mid-latitude region in the southern and northern hemispheres between longitudes of 100°E and 180°E during the magnetic storm period on Nov. 10, 2004, and a regular movement of the disturbing region was observed. In the end, the reason of the ionospheric fluctuation during this magnetic storm is analyzed.
