Kotova D S, Sinevich A A, Chernyshov A A, Chugunin D V, Jin Y, Miloch W J
Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316, Oslo, Norway.
Space Research Institute of the Russian Academy of Sciences, 117997, Moscow, Russia.
Sci Rep. 2025 Jan 27;15(1):3458. doi: 10.1038/s41598-025-86960-6.
In the subauroral zone at the boundary of the auroral oval in the evening and night hours during geomagnetic disturbances, a narrow (about 1°-2°) and extended structure (several hours in longitude) is formed. It is known as a polarization jet (PJ) or the subauroral ion drift (SAID). The PJ/SAID is a fast westward ion drift and is one of the main signatures of a geomagnetic disturbance in the subauroral ionosphere at the altitudes of the F-layer, when the geomagnetic AE index reaches more than 500 nT. Plasma speed in the PJ/SAID can reach several kilometres per second, and the size of plasma irregularities inside it can reach scales from tens of meters to several hundred meters. Such high velocities and structured plasma can affect trans-ionospheric radio waves and lead to scintillations in the received signal. We show that at the moment of auroral activity intensification, an increase in the magnitude of phase scintillation index (σ) as well as loss of satellite signals lock were observed in the region of the PJ/SAID equatorward of the auroral oval over Dronning Maud Land (Queen Maud Land) in Antarctica. We find that fluctuations inside the PJ/SAID can lead to serious deterioration of radio communication or navigational services. We emphasize the importance of considering the geometry of the beam passing from the GNSS satellite to the receiver on the ground. We highlight the mutual contribution of the PJ/SAID and the diffuse aurora boundary, which are almost impossible to separate in practice. Our results demonstrate the importance of considering the subauroral zone, where very dynamic plasma formations can occur with a strong flow and various-scale irregularities inside that lead to serious interference in satellite communications.
在地磁扰动期间的傍晚和夜间，在极光椭圆边界的亚极光区会形成一个狭窄（约1°-2°）且延伸的结构（经度上持续数小时）。它被称为极化喷流（PJ）或亚极光离子漂移（SAID）。PJ/SAID是一种快速向西的离子漂移，是F层高度的亚极光电离层中地磁扰动的主要特征之一，当地磁AE指数超过500 nT时会出现。PJ/SAID中的等离子体速度可达每秒数公里，其内部等离子体不规则性的尺寸可达数十米到数百米。如此高的速度和结构化的等离子体可影响跨电离层无线电波并导致接收信号的闪烁。我们表明，在极光活动增强的时刻，在南极毛德皇后地极光椭圆赤道侧的PJ/SAID区域内，观测到相位闪烁指数（σ）的幅度增加以及卫星信号锁定丢失。我们发现PJ/SAID内部的波动会导致无线电通信或导航服务严重恶化。我们强调考虑从全球导航卫星系统（GNSS）卫星到地面接收器的波束几何形状的重要性。我们突出了PJ/SAID和扩散极光边界的相互作用，实际上它们几乎无法分开。我们的结果表明考虑亚极光区的重要性，在该区域可能会出现非常动态的等离子体形成，伴有强烈的流动和内部各种尺度的不规则性，从而对卫星通信造成严重干扰。
