The Properties and Origins of Corotating Plasmaspheric Irregularities as Revealed Through a New Tomographic Technique
The Properties and Origins of Corotating Plasmaspheric Irregularities as Revealed Through a New Tomographic Technique
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通过新的断层扫描技术揭示的共旋转等离子体球不规则性的特性和起源
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发表时间：
2020
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通讯作者：
T. Clarke
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作者：
J. Helmboldt;J. Haiducek;T. Clarke
本文介绍了对共转等离子体层不规则性（CPI）的性质的见解，使这些结构的范围和时间分辨断层图像的新开发的方法。该方法基于使用干涉射电望远镜，甚大阵（VLA）对宇宙射电源测量的总电子含量梯度的高精度测量。利用VLA低波段电离层和瞬态实验数百小时的数据，我们确认CPI主要在夜间和L壳层探测到。结合这个大型数据集与其他电离层，大气和空间天气数据库，我们已经确定，当太阳和地磁活动水平较低时，CPI的检测率要高得多。我们还证明了更高的检测率与电离层电场扰动的驱动因素相吻合，包括零星的E波和重力波。最常与CPI相关的重力波源是急流弯曲/切变和亚暴触发的大气扰动。我们还表明，重力波驱动的电场扰动和与电浮力波/零星E相关的极化电场的等离子体层影响的模拟产生的结果与VLA观察到的结果非常相似。
This paper describes insights into the nature of corotating plasmaspheric irregularities (CPIs) enabled by a newly developed method for range‐ and time‐resolved tomographic images of these structures. The method is based on high‐precision measurements of total electron content gradients measure toward cosmic radio sources using an interferometric radio telescope, the Very Large Array (VLA). Exploiting hundreds of hours of data from the VLA Low‐band Ionosphere and Transient Experiment, we confirm that CPIs are predominantly detected at night and at L shells ∼ 2–4. Combining this large data set with other ionospheric, atmospheric, and space weather databases, we have established that CPI detection rates are much higher when levels of solar and geomagnetic activity are low. We also demonstrate that higher detection rates coincide with drivers of perturbations in the ionospheric electric field, including sporadic E and gravity waves. The gravity wave sources most commonly associated with CPIs are jet stream bend/shear and substorm‐triggered atmospheric disturbances. We also show that simulations of the plasmaspheric impact of both gravity wave‐driven electric field perturbations and polarization electric fields associated with electrobuoyancy waves/sporadic E produce results that are very similar to what is observed with the VLA.