Real-time imaging of density ducts between the plasmasphere and ionosphere
Real-time imaging of density ducts between the plasmasphere and ionosphere
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DOI：
10.1002/2015gl063699
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发表时间：
2015-05-28
影响因子：
5.2
通讯作者：
Williams, C. L.
中科院分区：
文献类型：
--
作者：
Loi, Shyeh Tjing;Murphy, Tara;Williams, C. L.
太阳光对地球大气层的电离在地球磁层内形成了复杂的多层等离子体环境，最内层是电离层和等离子体层。等离子体被认为是嵌入有圆柱形密度结构（管道）沿沿着地球磁场排列，但这些直接证据仍然很少。在这里，我们报告的第一个直接的广角观察广泛的阵列场对齐管道桥接上电离层和内部等离子体，使用一种新的地面成像技术。我们通过特征跟踪和视差分析来建立它们的高度和运动。这些结构有着惊人的组织性，看起来像是规则间隔的，高密度和低密度交替的管道，与地球磁场强烈对齐。这些发现代表了这种结构存在的第一个直接视觉证据。
Ionization of the Earth's atmosphere by sunlight forms a complex, multilayered plasma environment within the Earth's magnetosphere, the innermost layers being the ionosphere and plasmasphere. The plasmasphere is believed to be embedded with cylindrical density structures (ducts) aligned along the Earth's magnetic field, but direct evidence for these remains scarce. Here we report the first direct wide-angle observation of an extensive array of field-aligned ducts bridging the upper ionosphere and inner plasmasphere, using a novel ground-based imaging technique. We establish their heights and motions by feature tracking and parallax analysis. The structures are strikingly organized, appearing as regularly spaced, alternating tubes of overdensities and underdensities strongly aligned with the Earth's magnetic field. These findings represent the first direct visual evidence for the existence of such structures.