2011和2012年华南地区TEC耗空统计特征分析

Statistical analysis of characteristics of TEC depletions observed in 2011 and 2012 over South China

利用赤道异常北驼峰区深圳站2011年1月到2012年12月监测到的GPS-TEC数据,统计分析了华南地区电离层TEC耗空的时间和空间分布特征.结果表明：TEC耗空随时间、地理经纬度位置等变化呈现出不同的特征.前半夜和在赤道异常北驼峰区域,深度在20 TECU左右的耗空明显和强闪烁（S4≥0.5）相关,在后半夜或在赤道异常北驼峰外边缘区域,存在一些深度小于10 TECU的耗空对应着无闪烁现象发生.统计结果还表明：TEC耗空呈现出季节变化规律,2011和2012年TEC耗空主要出现在春秋分期间,TEC耗空深度主要分布为1~20TECU,持续时间集中在16~30 min,出现的时间主要集中在12：30-15：30UT（20：30-23：30LT）,午夜之后TEC耗空活动呈逐渐减弱趋势.

This paper presents the temporal and spatial distributions of TEC depletions over South China, based on the data observed at Shenzhen station, located under the northern crest of equatorial anomaly, from 2011 to 2012. Our results reveal that the characteristics of TEC depletions vary with local time （LT）, latitude and longitude. Deeper TEC depletions （approximately 20 TECU） well coincide with the occurrences of intense scintillations （S4≥0. 5）. But in post-midnight or at the north edge of equatorial anomaly over South China, some shallow TEC depletions （ 〈 10 TECU） were recorded along with the absence of scintillations （S4〉0. 2）. TEC depletions also showed seasonal variations. They occurred mainly in the vernal and autumnal equinox period during 2011 and 2012, with depth in the ranges of 1--20 TECU, and durations in the range of 16-30 minutes. Our results also suggest that most TEC depletions occurred between 20： 30 and 23： 30 LT, and gradually disappeared after 23：30 LT to local midnight.