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

摘要

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.%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-r.EC are also given in this paper.