Ionosonde observations of daytime spread F at low latitudes
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- 作者：Chunhua Jiang ; Guobin Yang ; Jing Liu ; Tatsuhiro Yokoyama ; Tharadol Komolmis ; Huan Song ; Ting Lan ; Chen Zhou ; Yuannong Zhang ; Zhengyu Zhao
- 刊名：Journal of Geophysical Research: Space Physics
- 出版年：2016
- 出版时间：December 2016
- 年：2016
- 卷：121
- 期：12
- 页码：12,093-12,103
- 全文大小：3.1MB
- ISSN：2169-9402
文摘
Spread F on ionograms has been considered to be a phenomenon mainly occurred at nighttime. This study presented a case study of daytime spread F observed by the ionosonde installed at Puer (PUR; 22.7°N, 101.05°E; dip latitude 12.9°N), where daytime spread F that lasted for more than 2 h (about 08:30 LT~10:45 LT) was observed on 14 November 2015. To investigate the possible mechanism, ionograms recorded at PUR and Chiang Mai (18.76°N, 98.93°E; dip latitude 9.04°N) were used in this study. We found that traveling ionospheric disturbances were observed before the occurrence of daytime spread F. Meanwhile, the movement of the peak height of the ionosphere was downward. We suggested that downward vertical neutral winds excited by traveling atmospheric disturbances/atmospheric gravity waves might play a significant role in forming daytime spread F over PUR during geomagnetic storms.