Nonspecular meteor trails from non‐field‐aligned irregularities: Can they be explained by presence of charged meteor dust?
Nonspecular meteor trails from non‐field‐aligned irregularities: Can they be explained by presence of charged meteor dust?
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DOI：
10.1002/2014gl059922
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发表时间：
2014-05
影响因子：
5.2
通讯作者：
Jorge L. Chau;I. Strelnikova;C. Schult;M. Oppenheim;Michael C. Kelley;G. Stober;Werner Singer
中科院分区：
文献类型：
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作者：
Jorge L. Chau;I. Strelnikova;C. Schult;M. Oppenheim;Michael C. Kelley;G. Stober;Werner Singer
非镜面流星回波与场向不规则性有关，并在低纬和中纬度地点被观测到。我们介绍了在高纬度获得的观测结果，其距离-时间特征类似于低纬度的观测结果。然而，这些回波不可能来自场对齐的不规则性，因为雷达指向角几乎与磁场平行。使用干涉计量学，我们已经能够区分空间和时间特征。我们的回声可以定性地解释为存在带电的尘埃，这些尘埃是由浸没在湍流中的陨石物质形成的。这可能导致高施密特数的等离子体，可以维持米级的湍流，就像它对极地中间层夏季回波所做的那样。这些罕见事件需要相对较大的流星体。这一结果强调了带电尘埃在理解所有长时间非镜面流星回波方面的重要性。这种尘埃将延长它们的扩散时间，并将影响从镜面反射回波估计温度。
Nonspecular meteor echoes have been associated with field‐aligned irregularities and have been observed at low‐latitude and midlatitude sites. We present observations obtained at high latitudes with range‐time features that resemble those at lower latitudes. However, these echoes cannot come from field‐aligned irregularities, since the radar‐pointing angles are almost parallel to the magnetic field. Using interferometry, we have been able to discriminate space and time features. Our echoes could be qualitatively explained by the presence of charged dust forming from the meteoric material immersed in a turbulent flow. This can lead to a high Schmidt number plasma that can sustain meter‐scale turbulence just as it does for the polar mesospheric summer echoes. These rare events require relatively large meteoroids. The result emphasizes the importance of charged dust in understanding all long‐duration nonspecular meteor echoes. This dust will extend their diffusion times and will affect temperature estimations from specular echoes.