Long-Term Observations of the Thermospheric 6 h Oscillation Revealed by an Incoherent Scatter Radar over Arecibo
Long-Term Observations of the Thermospheric 6 h Oscillation Revealed by an Incoherent Scatter Radar over Arecibo
复制标题
DOI：
10.3390/rs15215098
复制
发表时间：
2023-10
期刊：
影响因子：
--
通讯作者：
Yun Gong;Yaxuan Ding;Xinkun Chen;Shaodong Zhang;Qihou H. Zhou;Zheng Ma;Jiahui Luo
中科院分区：
文献类型：
--
作者：
Yun Gong;Yaxuan Ding;Xinkun Chen;Shaodong Zhang;Qihou H. Zhou;Zheng Ma;Jiahui Luo
本文分析了150 ~ 400公里热层中的6 h振荡。该分析应用了1984年至2015年位于阿雷西博天文台（18.3°N，66.7°W）的非相干散射雷达的134天数据。据我们所知，在热层的6小时振荡的气候和季节特征进行了调查，第一次在阿雷西博。热层6 h振荡的气候平均振幅约为11 m/s，随着高度的增加，振幅缓慢增加。6小时振荡的气候平均振幅与250公里以上的阿雷西博半日潮和半日潮相当。气候平均相位的垂直变化有限。6 h振荡在秋季最为显著，振幅可达20 m/s左右，而其他季节约为10 m/s。四季的位相结构都表现出较弱的垂直变化。本文还分析了热层6 h振荡对太阳活动和地磁活动的响应。结果表明，在低纬地区，太阳活动对热层6 h振荡的影响较小，但随着地磁活动的增加，热层6 h振荡的幅度增大。在250 km以上，强地磁活动时6 h振荡的振幅可达20 m/s左右，几乎是弱地磁活动时6 h振荡振幅的两倍。
We present an analysis of 6 h oscillations in the thermosphere ranging from 150 km to 400 km. The analysis applies 134 days of data from an incoherent scatter radar located at Arecibo Observatory (18.3°N, 66.7°W) from 1984 to 2015. To our knowledge, the climatological and seasonal characteristics of the 6 h oscillations in the thermosphere were investigated for the first time over Arecibo. The climatological mean amplitude of the 6 h oscillation in the thermosphere is about 11 m/s, and it increases slowly with altitude above 225 km. The climatological mean amplitude of the 6 h oscillation is comparable with semidiurnal and terdiurnal tides at Arecibo above 250 km. The climatological mean phase exhibits limited vertical variation. The 6 h oscillation is the most prominent in autumn, with amplitudes reaching around 20 m/s compared to approximately 10 m/s in other seasons. The phase structure in all seasons exhibits weak vertical variations. The responses of the thermospheric 6 h oscillation to solar and geomagnetic activities are also analyzed in this study. Our results indicate that at low latitude, solar activities have a small impact on the variation in the thermospheric 6 h oscillation, while it appears that the amplitude of the 6 h oscillation increases with increasing geomagnetic activity. Above 250 km, the amplitude of the 6 h oscillation reaches ~20 m/s during strong geomagnetic activity, which is almost twice of that occurring during weak geomagnetic activity.