First Simultaneous Lidar Observations of Thermosphere‐Ionosphere Sporadic Ni and Na (TISNi and TISNa) Layers (∼105–120 km) Over Beijing (40.42°N, 116.02°E)
First Simultaneous Lidar Observations of Thermosphere‐Ionosphere Sporadic Ni and Na (TISNi and TISNa) Layers (∼105–120 km) Over Beijing (40.42°N, 116.02°E)
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DOI：
10.1029/2022gl100397
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发表时间：
2022-08
影响因子：
5.2
通讯作者：
Fuju Wu;X. Chu;Lifang Du;J. Jiao;Haorang Zheng;Yuchang Xun;W. Feng;J. Plane;Guotao Yang
中科院分区：
文献类型：
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作者：
Fuju Wu;X. Chu;Lifang Du;J. Jiao;Haorang Zheng;Yuchang Xun;W. Feng;J. Plane;Guotao Yang
我们报告了北京延庆（40.42°N，116.02°E）上空海拔约 105-120 公里处热层-电离层零星镍和钠（TISNi 和 TISNa）层的首次同步激光雷达观测。从2019年4月至2020年4月和2020年7月至2021年6月的两年数据来看，5月和6月的TISNi层密度较高，2021年5月17日最大密度为818 cm−3，超过主层峰值（~85 km）密度~4倍。它们与附近观察到的强烈零星 E 层相关。 TISNa 层出现在与 TISNi 相似的高度，时空相关系数约为 1。 TISNi 中 Ni 的富集很明显，[TISNi]/[TISNa] 柱丰度比约为 1，约为主层 [Ni]/[Na] 比值的 10 倍。这些结果在很大程度上是通过与电子重组中和会聚的 Ni+ 和 Na+ 离子来解释的。计算表明~105公里以上直接重组优于解离重组。
We report the first simultaneous lidar observations of thermosphere‐ionosphere sporadic nickel and Na (TISNi and TISNa) layers in altitudes ∼105–120 km over Yanqing (40.42°N, 116.02°E), Beijing. From two years of data spanning April 2019 to April 2020 and July 2020 to June 2021, TISNi layers in May and June possess high densities with a maximum of 818 cm−3 on 17 May 2021, exceeding the density of main layer peak (∼85 km) by ∼4 times. They correlate with strong sporadic E layers observed nearby. TISNa layers occur at similar altitudes as TISNi with spatial‐temporal correlation coefficients of ∼1. The enrichment of Ni in TISNi is evident as the [TISNi]/[TISNa] column abundance ratios are ∼1, about 10 times the main layer [Ni]/[Na] ratios. These results are largely explained by neutralization of converged Ni+ and Na+ ions via recombination with electrons. Calculations show direct recombination dominating over dissociative recombination above ∼105 km.