空间科学学报2025，Vol.45Issue(6)：1451-1459,9.DOI:10.11728/cjss2025.06.2024-0136
1998-2020年120°E上空电离层赤道异常冬季纬度偏移现象及其影响机制
EIA Latitude Offset Phenomenon in Winter and Its Impact Mechanism around 120°E Longitude during 1998-2020
摘要
Abstract
Based on the Total Electron Content(TEC),F2 layer critical frequency(f0F2),and peak height(hmF2)data provided by the institute of IZMIRAN of the Russian Academy of Sciences from 1998 to 2020,this study analyzes the morphological features of the hemispheric asymmetry and latitude offset phenomenon of the Equatorial Ionization Anomaly(EIA)over 120°E during geomagnetically quiet peri-ods,especially during low solar activity,and explores the possible influencing mechanisms.The results showed that the hemispherical asymmetry features of EIA structure that vary with solar activity are sig-nificantly different during the summer and winter solstice.The asymmetry exhibits a significant correla-tion with the solar activity during winter solstice.However,there is a weak negative correlation during the summer solstice.The latitude position of EIA structure moves southward in winter months and the latitude deviation of southern anomaly crest is more significant,especially during the low solar activity.During the winter solstice over 120°E,trans-equatorial neutral winds are the main factor affecting the hemispheric asymmetry of EIA peak intensities.Excluding the influences of geomagnetic activity and magnetic declination,the primary factor for the latitude shifts of the EIA double-peak structure in win-ter may be related to the geographic control effect of the plasma density background field around the subsolar point.At where,photo-ionization can produce more electrons,and the effect may plays an im-portant role in Southward offset phenomenon of EIA structure in winter around 120°E longitude.Mean-while,the impact of the geographic control influence still requires further research and validation through theoretical models and simulation studies.These findings provide new insights into the complex behaviors of the EIA under varying solar conditions,highlighting the significant role of subsolar point positioning in modulating ionospheric EIA structures.关键词
赤道异常/半球不对称性/纬度偏移Key words
Equatorial ionization anomaly/Hemispheric asymmetry/Latitude offset分类
天文与地球科学引用本文复制引用
HUANG Linfeng,WANG Jinsong,SONG Shanhai,YANG Shijin,LIAO Yao..1998-2020年120°E上空电离层赤道异常冬季纬度偏移现象及其影响机制[J].空间科学学报,2025,45(6):1451-1459,9.基金项目
国家自然科学基金项目资助(42274217) （42274217）
