Spatial Characteristics on the Occurrence of the Nighttime Midlatitude Medium-Scale Traveling Ionospheric Disturbance at Topside Ionosphere Revealed by the Swarm Satellite
Spatial Characteristics on the Occurrence of the Nighttime Midlatitude Medium-Scale Traveling Ionospheric Disturbance at Topside Ionosphere Revealed by the Swarm Satellite
复制标题
群卫星揭示的上部电离层夜间中纬度中尺度行进电离层扰动的空间特征
DOI：
10.1029/2019ja027739
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发表时间：
2020
影响因子：
2.8
通讯作者：
Yin Fan
中科院分区：
文献类型：
--
作者：
Wan Xin;Xiong Chao;Wang Hui;Zhang Kedeng;Yin Fan
Using 6 years collecting of electron density (Ne) data from the Swarm A satellite, this study portrays comprehensive maps of the occurrence of medium‐scale traveling ionospheric disturbance (MSTID) at middle latitudes, which is characterized by the in situ absoluteNefluctuations above a certain threshold. Two interesting spatial preferences on the occurrence of MSTID as well as their dependence on local time and solar cycle are captured, that is, (1) regional preference near Weddell Sea Anomaly (WSA) to its west during December solstice, MSTID in this region appears even at very low latitudes (at least to 10°N in magnetic latitude) and (2) preference at middle latitudes with a wide zonal extension, which is similar to the recently disclosed nighttime midlatitude plasma band‐like enhancement (NMPBE) of the background plasma density (Zhong et al., 2019, https://doi.org/10.1029/2018JA026059). The first preference of MSTID occurring near WSA region can be understood as the effects of horizontal neutral wind contribution to the Perkins instability, with the principal requirement of sporadicEoccurrence via ionosphericE‐Fregion coupling. The fundamental mechanism of the second preference of MSTID occurring includes the interhemispheric coupling that the MSTID can also develop in the winter hemisphere where the local growth rate of Perkins instability is low. Besides, the presence of NMPBE during low solar activity years sets up a favorable environment for the appearance of MSTID with considerable fluctuation amplitude.
