南极威德尔海电离层异常的综合观测及分析
Comprehensive Observation and Analysis of Weddell Sea Anomaly in Antarctica
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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。本文用西南极地区的GPS跟踪站数据和测高卫星Jason-2数据,分别提取了陆地和海洋地区大范围的电离层TEC参数。GPS反演结果的优势是获取测站上空高精度的TEC时间序列,测高反演的结果整体与GPS的结果精度相当,虽然测高的时间分辨率较低,但其优势是获取海洋广大区域的TEC值。两种观测手段的研究区域互补,可以充分观测威德尔海异常在西南极的变化特征,从空间上来看,威德尔海异常出现在以别林斯高晋海为中心的广大区域,而威德尔海异常也是覆盖了西南极的别林斯高晋海、威德尔海以及可达80°S的西南极陆地区域。从时间上来看,出现时段在每年的10月底到次年3月初,夜晚电子密度增加,白天电子密度降低,随着太阳活动的增强,其异常程度也变大。Abstract: Weddell sea anomaly, appeared in west Antarctica, is an ionospheric anomaly. In this paper ground-based, GPS data and altimetry satellite Jason-2 data in west Antarctica are used to extract TEC in continental and oceanic areas respectively. The advantages of ground-based GPS are to obtain TEC time series over the station. TEC results of satellite altimetry and ground-based GPS are at the same precision level. Although the time resolution of satellite altimetry is lower, the advantages of satellite altimetry are to be observed in ocean areas. The two observations are complementary, which is valuable to depict the comprehensive characteristics of WSA in west Antarctic together. In view of space, WSA appeared mainly in Bellingshausen Sea, and also covered Bellingshausen sea and the Weddell sea, as well as up to 80° S of the west Antarctic continent. In view of time, the period of the appearance is from Oct. to Mar. next year, with the characteristics of low electron density in daytime but high electron density in nighttime, and the abnormal degree become larger in high solar activity.