On the Genesis of Postmidnight Equatorial Spread F: Results for the American/Peruvian Sector
On the Genesis of Postmidnight Equatorial Spread F: Results for the American/Peruvian Sector
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关于午夜后赤道传播 F 的起源：美国/秘鲁部门的结果
DOI：
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发表时间：
2018
影响因子：
5.2
通讯作者：
M. Milla
中科院分区：
文献类型：
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作者：
Weijia Zhan;F. Rodrigues;M. Milla
先前使用通信/导航中断预报系统（C/NOFS）卫星上的传感器进行的现场测量对地球低纬度电离层进行的研究表明，在2008-2009年深太阳极小期的6月和12月至月期间，赤道扩展F（ESF）事件在午夜后部门意外占主导地位。有人认为，这些事件可能是由赤道等离子体漂移的不寻常行为驱动的，在同一时期，赤道等离子体漂移在午夜前后显示出异常的上升峰。我们使用在秘鲁的Jicamarca射电天文台（11.95°S，76.87°W，101 ° dip lat）进行的相干后向散射雷达（Jicamarca Unattended Long‐term Investigations of the Ionosphere and Atmosphere ‐ JULIA）测量，以更好地理解C/NOFS观测到的ESF不规则性的起源。雷达观测表明，在12月至日期间的ESF事件开始于日落后的部门。这些ESF事件及其发展条件显示持续到午夜。在十二月至期间C/NOFS观测的postmidnight不规则性的优势是由ESF结构的缓慢垂直发展造成的，在大多数情况下，ESF结构仅在午夜附近到达顶侧。然而，在6月至日，JULIA的观测表明ESF主要在午夜到午夜后的扇区开始。配置的数字探空仪观测提供了导致这些ESF事件的F区条件的额外见解。
Previous studies of the Earth's low‐latitude ionosphere using in situ measurements made by sensors on the Communication/Navigation Outage Forecasting System (C/NOFS) satellite showed an unexpected predominance of equatorial spread F (ESF) events in the postmidnight sector during June and December solstice months of the 2008–2009 deep solar minimum. It has been suggested that these events might have been driven by the unusual behavior of the equatorial plasma drifts, which showed an abnormal upward peak around midnight during the same period. We use coherent backscatter radar (Jicamarca Unattended Long‐term Investigations of the Ionosphere and Atmosphere ‐ JULIA) measurements made at the Jicamarca Radio Observatory (11.95°S, 76.87°W, ∼1∘ dip lat) in Peru to better understand the origin of the ESF irregularities observed by C/NOFS. The radar observations show that ESF events during December solstice start in the postsunset sector. These ESF events and the conditions for their development are shown to continue through midnight hours. The predominance of postmidnight irregularities on C/NOFS observations during December solstice is caused by the slow vertical development of the ESF structures, which only reach the topside near midnight in most cases. On June solstice, however, JULIA observations show that ESF started predominately in the midnight to postmidnight sector. Collocated digisonde observations provide additional insight on F‐region conditions leading to these ESF events.