Unexpected High Occurrence of Daytime F-Region Backscatter Plume Structures Over Low Latitude Sanya and Their Possible Origin
Unexpected High Occurrence of Daytime F-Region Backscatter Plume Structures Over Low Latitude Sanya and Their Possible Origin
复制标题
低纬度三亚地区日间F区后向散射烟羽结构的意外高发及其可能成因
DOI：
10.1029/2020gl090517
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发表时间：
2020
影响因子：
5.2
通讯作者：
Li Guozhu
中科院分区：
文献类型：
--
作者：
Xie Haiyong;Yang Sipeng;Zhao Xiukuan;Hu Lianhuan;Sun Wenjie;Wu Zhi;Ning Baiqi;Liu Libo;Li Guozhu
电离层F区不规则后向散射羽流通常被认为是赤道和低纬度地区的夜间现象。使用三亚（18.4°N, 109.6°E，倾角较晚）。在0700 ~ 1800lt的白天观测到12.8°N) VHF雷达的F区后向散射回波，在太阳极小期的6月至出现了意外的高频率。雷达干涉测量和ICON卫星原位测量结果表明，白天F区回波来自由场向不规则结构组成的羽流结构。白天回声结构主要出现在海拔350公里以上，延伸至650公里以上，有时有明显的西移。我们推测，白天的F区回波是由于前一天晚上在100-125°E附近产生的赤道等离子体气泡不规则性造成的，在那里，不规则性可能会持续很长时间，在日出之后以垂直拉长的化石羽流的形式存在。在电离层背景动力学下，化石羽流可能会上升到高海拔，并在三亚上空纬向漂移。
Ionospheric F‐region irregularity backscatter plumes are commonly regarded as a nighttime phenomenon at equatorial and low latitudes. Using the Sanya (18.4°N, 109.6°E, dip lat. 12.8°N) VHF radar, F‐region backscatter echoes were observed at daytime during 0700–1800 LT, with an unexpected high occurrence in June solstice of solar minimum. Radar interferometry and ICON satellite in situ results show that the daytime F‐region echoes were from plume structures consisting of field‐aligned irregularities. The daytime echoing structures appeared mostly above 350 km altitude, extending up to 650 km or more with apparent westward drifts at times. We surmise that the daytime F‐region echoes were due to equatorial plasma bubble irregularities generated on the previous night around 100–125°E, where the irregularities could survive unexpectedly long time, beyond sunrise as vertically elongated fossil plumes. Under the ionospheric background dynamics, the fossil plumes could be elevated to high altitudes and drift zonally over Sanya.