Strong evidence for couplings between the ionospheric wave‐4 structure and atmospheric tides
Strong evidence for couplings between the ionospheric wave‐4 structure and atmospheric tides
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DOI：
10.1029/2011gl047855
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发表时间：
2011-07
影响因子：
5.2
通讯作者：
M. He;Libo Liu;W. Wan;Yong Wei
中科院分区：
文献类型：
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作者：
M. He;Libo Liu;W. Wan;Yong Wei
最近，在赤道电离层中发现了所谓的“波-4结构”，它描述了相互分离约90°的四个经度扇区内的等离子体密度增强。这种结构被认为是由DE 3的潮汐模式（日向东传播，纬向波数为3）控制的，这种模式是由陆地-海洋差异引起的热带对流层不同加热所激发的。在这里，我们使用从COSMIC数据集中提取的F2层峰密度（NmF 2）和峰高（hmF 2），通过将其分解为半球间对称和反对称分量来研究波4结构。结果表明，E区发电机的DE 3调制机制只考虑了白天对称分量，而反对称分量可以用跨赤道中性风中的SE 2（semidiernailedeast-propagating with zonal wave number-2）潮汐来解释。令人惊讶的是，反对称分量在夜间主导hmF 2的4波结构，这表明SE 2跨赤道风是hmF 2夜间4波结构的主要贡献者。
Recently a so‐called “wave‐4 structure” was discovered in the equatorial ionosphere, which describes plasma density enhancements within four longitude sectors separated about 90° from each other. This structure was proposed to be controlled by the tide mode of DE3 (diurnal eastward‐propagating with zonal wave number‐3) excited by different heating in the tropical troposphere due to land‐sea differences. Here, using F2‐layer peak density (NmF2) and the peak height (hmF2) extracted from the COSMIC data set, we investigate the wave‐4 structure by decomposing it into interhemispheric symmetric and antisymmetric components. Our results indicate that the generally accepted mechanism of DE3 modulation of E region dynamo only accounts for the daytime symmetric components, while the antisymmetric components could be explained well in the terms of the SE2 (semidiurnal eastward‐propagating with zonal wave number‐2) tide in transequatorial neutral wind. Surprisingly, the antisymmetric component dominates the wave‐4 structure in hmF2 during nighttime, suggesting the SE2 transequatorial wind is the leading contributor to the nighttime wave‐4 structure in hmF2.