利用GPS观测数据和IRI模型对比分析太阳活动低年广州地区电离层TEC变化

电离层TEC是描述电离层特性的一个重要参量,利用GPS观测数据（包括广州站接收的GPS-TEC数据和国际GNSS提供的IGS-TEC数据）与IRI-2007模型计算的TEC预测值对太阳活动低年2008年的广州地区TEC周日和季节变化以及年变化特征等进行了多方面的对比分析。结果表明：TEC观测值白天较高且变化迅速,夜间较低且变化缓慢,同时表现出明显的季节依赖性和半年变化特性,全年在春秋分季节出现两次峰值,IRI-TEC预测值能较好地反映GPS观测值,但局部上也存在着一些偏差,并对其中的物理机制和产生差异的原因给出了合理的分析和解释。

GPS-Observation-Data-and IRI-Model-based Contrastive Analysis on Ionospheric TEC Changes of Guangzhou Region during Low Solar Activity Years

The ionospheric total electron content(TEC) is an important parameter to describe the character of the ionosphere.GPS observation data(GPS-TEC data recorded at Guangzhou Meteorological Satellite Ground Station and IGS-TEC data provided by the International GNSS Service) as well as predicted TEC data derived from IRI-2007 model are used to conduct contrastive analysis on the weekday,seasonal and annual variation characteristics of TEC over Guangzhou during 2008,a low solar activity year,from various perspectives.The results show that the observed TEC value is high at daytime and low at nighttime,with obvious semi-annual and seasonal variation characteristic,and two peak values in Spring and Autumnal Equinox.A good agreement is found between IRI-TEC and GPS-TEC at daytime,whereas a little large deviation at nighttime.Physical mechanism to explain the variation character of TEC and some reasons to explain the deviation between IRI-TEC and GPS-TEC are also given in this paper.