Sporadic structures in the atmospheric sodium layer
Sporadic structures in the atmospheric sodium layer
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DOI：
10.1029/2003jd004496
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发表时间：
2004-06-15
影响因子：
4.4
通讯作者：
Batista, IS
中科院分区：
文献类型：
--
作者：
Clemesha, BR;Batista, PP;Batista, IS
激光雷达在许多地点观察到在中层顶附近零星地出现大气金属层浓度升高的现象。这些层比背景层薄得多，持续几分钟到几个小时，似乎与电离层零星E有关。一种更罕见的瞬变层类型在文献中只被凯恩等人报道过一次。[2001]。在阿雷西博(北纬18.3度，西经66.7度)工作的激光雷达在钠中观测到的这些层，在激光雷达高度/时间显示屏上显示为C形结构。这些结构在大约100公里处被观测到，持续时间约为30分钟，似乎与正常的零星金属层无关，阿雷西博的工作人员表示，它们可能是由波浪破碎或开尔文-海姆霍尔茨巨浪产生的。在圣何塞多斯坎波斯(南纬23度，西经46度)，我们只偶尔观察到钠层中的C-结构，但对其形成的分析以及同时的流星风测量表明，观察到的结构可能是先前存在的钠浓度增强的云的风切变扭曲的结果。
The sporadic occurrence of layers of enhanced concentration of meteoric metals in the vicinity of the mesopause has been observed by lidar at many locations. These layers are much thinner than the background layer, last between a few minutes and many hours, and appear to be related to ionospheric sporadic E. A much more rare type of transient layer has been reported in the literature only once, by Kane et al. [2001]. The layers in question, observed in sodium by a lidar operating at Arecibo (18.3degreesN, 66.7degreesW), appear as C-shaped structures in the lidar height/time display. The structures, which have been observed at around 100 km, with durations around 30 min, appear not to be related to normal sporadic metals layers, and the Arecibo workers suggest that they might be produced by wave-breaking or Kelvin-Helmholtz billows. At Sao Jose dos Campos (23degreesS, 46degreesW) we observe C-structures in the sodium layer only very occasionally, but an analysis of their formation, together with simultaneous meteor winds measurements, suggests that the observed structures might be the result of wind-shear distortion of preexisting clouds of enhanced sodium concentration.