中文摘要：

威德尔海异常是西南极沿海地区在夏季出现的电离层异常现象,以子夜时电子密度增强为主要特征.于1958年首次观测发现,但囿于观测手段的限制,其研究进展缓慢.2003年,有学者利用TOPEX卫星分析了大范围的威德尔海异常,随后关于威德尔海异常的研究重新兴起.与COSMIC和TOPEX等的结果相比,地基GPS最大的优点是提供连续时间尺度的观测结果.本文用地基GPS数据提取了威德尔海异常,进而分析其时空特征.这一异常在太阳活动活跃期表现出了更为明显的特征.其覆盖范围包括了威德尔海、别林斯高晋海和南美南端的广大区域,且出现的时刻比较一致,说明这一异常特征是在短时间内大范围出现的.在春夏交替的时刻会出现双峰现象,在夏季时,地方时正午的TEC值反而会比春夏交替时的TEC值更低.

英文摘要：

Weddell Sea Anomaly,appeared in West Antarctica,is an ionospheric anomaly,which is characterized by electron increase in night.The phenomenon is observed first in 1958,due to the limitation of equipments,the research progress is relative low.In 2003,some scholars analyzed WSA with TOPEX data,and then the research on WSA re-attracted the attention of scientists.Compared to COSMIC and TOPEX data,the ground-based GPS can provide the consecutive observation.In this paper,ground-based GPS data are used to extract TEC,and its temporal and spatial characteristics are analyzed.WSA showed more obvious anomalies in active solar activity.The coverage includes Weddell Sea,Bellingshausen Sea,and the southern tip of South America,and the anomalies appear at the same time,which mean the characteristics of short time and wide area.In late spring and early summer,double peaks appear in a day.TEC at noon in summer is lower than that in late spring and early summer.