河北区域电离层精细建模及磁暴响应特征研究

Fine Modeling of Regional Ionosphere in Hebei and Research on Response Characteristics of Magnetic Storm

经常发生的地磁暴可引起电离层异常,并导致穿过电离层的GNSS导航信号产生异常延迟甚至难以被观测处理。因此,有必要对地球磁暴引起的电离层异常响应特征开展系统深入研究。在已有的全球电离层异常研究基础上,充分发挥了省级连续运行参考站(Continuous Operation Reference Station,CORS)网测站密度大、数据细节丰富的优势,建立了区域电离层模型,精细化提取了电离层异常值。初步分析了磁暴期间电离层异常响应的时序关系、量级大小、空间分布和变化规律等:(1)磁暴与区域电离层异常之间的时间响应特征显示,地球磁暴可引起电离层异常,电离层异常在响应时间方面具有拖尾效应,磁暴结束24 h后电离层才恢复至磁暴前正常水平。(2)磁暴引起电离层垂直电子总含量(Vertical Total Electron Content,VTEC)异常变化的量级特征显示,小磁暴引起电离层天顶方向电子总量增大约9.5 TECU,对应视线方向电子总量增大约36 TECU。(3)磁暴引起电离层异常的空间分布特征显示,高纬度地区的电离层异常响应大于低纬度地区。(4)电离层异常响应的空间变化特征显示,磁暴期间电离层异常响应首先呈现出从南向北增大延伸态势;当电离层VTEC及其异常值达到峰值后,电离层异常响应呈现从北向南减弱回归态势。

Frequent geomagnetic storms can cause ionospheric anomalies,and lead to abnormal delays or even difficulty in observing and processing of GNSS navigation signals passing through the ionosphere.Therefore,it is necessary to carry out systematic and in-depth research on the response characteristics of ionospheric anomalies caused by geomagnetic storms.On the basis of the existing global ionospheric anomaly research,the advantages of large density and rich data details of provincial Continuous Operation Reference(CORS)network stations are fully utilized,and a regional ionospheric model is established,and the extraction the ionospheric anomaly values is refined.The temporal relationship,magnitude,spatial distribution and change law of the response of ionospheric anomaly during the magnetic storm are preliminarily analyzed.①The time response characteristics between the geomagnetic storm and the regional ionospheric anomaly show that the geomagnetic storm can cause the ionospheric anomaly which has a tailing effect in response time.After 24 h of the end of the magnetic storm,the ionosphere returned to the normal level before the magnetic storm.②The magnitude characteristics of the ionospheric Vertical Total Electron Content(VTEC)anomaly caused by the magnetic storm show that the total amount of electrons in the ionospheric zenith direction caused by a small magnetic storm is increased by about 9.5 TECU,and the total amount of electrons in the corresponding line-of-sight direction caused by a small magnetic storm is increased by about 36 TECU.③The spatial distribution characteristics of ionospheric anomalies caused by magnetic storms show that the response of ionospheric anomalies in high latitudes is greater than that in low latitudes.④The spatial variation characteristics of the ionospheric anomaly response show that during the magnetic storm,the ionospheric anomaly response first shows a trend of increasing and extending from south to north.When the ionospheric VTEC and its anomalous value reached the peak,the ionospheric anomalous response shows a trend of weakening and returning from north to south.