Lidar observations of sporadic sodium layers at Mauna Kea Observatory, Hawaii
Lidar observations of sporadic sodium layers at Mauna Kea Observatory, Hawaii
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DOI：
10.1029/jd093id11p14199
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发表时间：
1988-11
影响因子：
--
通讯作者：
K. H. Kwon;D. Senft;C. Gardner
中科院分区：
文献类型：
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作者：
K. H. Kwon;D. Senft;C. Gardner
描述了在夏威夷莫纳克亚山（北纬19°50′，西经155°28′）上空观测到的非常密集、狭窄的高层大气钠层的特征。在1987年1月17日至22日进行的30小时激光雷达测量期间，共观测到这些层16次。1月21日夜间形成的最显著的偶发层在96公里附近呈现出2.8×10⁴厘米⁻³的峰值密度，全宽约2公里。该层的快速增长和衰减持续了约40分钟。该层的表观钠产生和衰减速率约为60厘米⁻³秒⁻¹。即使在衰减之后，该狭窄层仍被连续观测了近8小时。在此期间，该层稳定向下移动，平均表观速度为31厘米秒⁻¹。这16个偶发层最显著的特征似乎是出现时间。这些层要么在当地标准时间2100至2330之间的傍晚形成，要么在当地标准时间0300至0600之间的清晨形成。在3个不同的日子里，清晨的层在当地标准时间0253至0308的15分钟短时间内开始形成。清晨层最大峰值密度的平均时间比傍晚层的大约晚6小时。造成这些层的机制似乎与全日潮和偶发E层有关。
The characteristics of very dense, narrow upper atmospheric Na layers observed above Mauna Kea, Hawaii (19°50′N, 155°28′W) are described. These layers were observed on a total of 16 occasions during 30 hours of lidar measurements from January 17 to 22, 1987. The most prominent sporadic layer, which formed on the night of January 21, exhibited a peak density of 2.8×104 cm−3 near 96 km, with a full width of about 2 km. The rapid growth and decay of the layer lasted for about 40 min. The apparent Na production and decay rates of this layer were approximately 60 cm−3 s−1. Even after the decay, the narrow layer was observed continuously for almost 8 hours. During this period the layer moved downward steadily, with a mean apparent velocity of 31 cm s−1. The most significant characteristic of the 16 sporadic layers appears to be occurrence times. The layers formed either in the late evening, between 2100 and 2330 LST, or in the early morning, between 0300 and 0600 LST. The layers of the early morning began forming within a short time span of 15 min from 0253 to 0308 LST on 3 different days. The mean time of the maximum peak density of the early morning layers occurred about 6 hours after that of the late evening layers. The mechanisms responsible for creating these layers appear to be related to diurnal tides and sporadic E layers.