Abstract. Polar holes were observed in the high-latitude ionosphere during a series of multi-instrument case studies close to the Northern Hemisphere winter solstice in 2014 and 2015. These holes were observed during geomagnetically quiet conditions and under a range of solar activities using the European Incoherent Scatter (EISCAT) Svalbard Radar (ESR) and measurements from Global Navigation Satellite System (GNSS) receivers. Steep electron density gradients have been associated with phase scintillation in previous studies; however, no enhanced scintillation was detected within the electron density gradients at these boundaries. It is suggested that the lack of phase scintillation may be due to low plasma density levels and a lack of intense particle precipitation. It is concluded that both significant electron density gradients and plasma density levels above a certain threshold are required for scintillation to occur.

中文翻译：

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极地电离层孔边缘的等离子体密度梯度：没有相位闪烁

摘要。在 2014 年和 2015 年接近北半球冬至的一系列多仪器案例研究中，在高纬度电离层中观察到极洞。这些极洞是在地磁安静条件下和一系列太阳活动下使用欧洲不相干散射 (EISCAT) 斯瓦尔巴雷达 (ESR) 和来自全球导航卫星系统 (GNSS) 接收器的测量值。在之前的研究中，陡峭的电子密度梯度与相位闪烁有关。然而，在这些边界处的电子密度梯度内没有检测到增强的闪烁。有人认为，缺乏相闪烁可能是由于等离子体密度水平低和缺乏强烈的粒子沉淀。