SAMI2物理模型与东亚扇区GPS TEC数据比较研究

Comparison between SAMI2 TEC and GPS TEC in East Asia sector

SAMI2(Sami2 is Another Model of the Ionosphere)是美国海军实验室开发的电离层物理模型.利用该物理模型,模拟了东亚扇区不同太阳活动强度、不同纬度地区三个站的电离层电子浓度总含量(TEC).通过模拟结果与GPS观测站TEC数据的比较,检验SAMI2在此扇区的电离层TEC计算精度.结果表明,物理模型输出的电离层TEC具备与观测数据一致的周日变化、季节变化,太阳活动变化.周日分布上,上午时段SAMI2 TEC与观测数据吻合度优于午后时段;季节分布上,SAMI2 TEC在冬季与观测值偏差小于其他季节;SAMI2 TEC与GPS TEC相关系数各站均达到0.87以上,与赤道地区Guam站相关性最好;太阳活动低年计算结果优于太阳活动高年;多数情况下,SAMI2 TEC相对GPS TEC偏大.本文结果为基于SAMI2模型构建背景误差分布特征,开展该区域电离层数值预报研究可行性提供了理论支持.

SAMI2(Sami is Another Model of the Ionosphere)is a theoretical ionosphere model developed by the U.S.Navy Research Lab(NRL)which has been widely used in ionospheric research.In this paper,the total electron content(TEC)of ionosphere from SAMI2 and GPS at different latitudes in East Asia sector with different solar activities have been selected as a comparison to estimate the accuracy of SAMI2.The results show that the SAMI2 TEC have same diurnal,seasonal and solar activity variations with GPS TEC.SAMI2 coincides better with the observation data in morning than in the afternoon.In the seasonal distribution,SAMI2 TEC has small deviation from the observation in winter.The correlation coefficient between SAMI2 TEC and GPS TEC is above 0.87 at each station.In most cases,the SAMI2 overestimate the ionosphere TEC.