We briefly describe the results of the first (undedicated) experiments on studying large-scale (about 1000 km) aperiodic and quasi-periodic disturbances in the lower and middle ionosphere. The main results of modern experiments are listed. Multi-instrument radiophysical observations of large-scale (about 1000 km) aperiodic disturbances in the lower ionosphere and quasi-periodic disturbances in the middle ionosphere, which accompanied the Sura heater action with high-power (effective power 40–95 MW) nonstationary radio emission, were performed in 2017–2018 using partial-reflection and vertical/oblique multipath multifrequency sounding techniques. The observations were performed in the observatories of the V. N. Karazin National University of Kharkov during four heating campaigns in 2017–2018. The aperiodic disturbances in the lower ionosphere had a delay time of 15–18 min and a duration of 5–10 min. The disturbances followed the heater switch-on and off. The nature of these disturbances is discussed. The main effects in the middle ionosphere include the following. When the effective radiated power is no less than 40–60 MW, the Doppler spectra become considerably broader and multipathing appears on radio paths that are 1000 km distant from the heater in 40–60 min after the Sura switch-on. Periodic heating of the ionosphere resulted in periodic variations in the Doppler frequency shift (with a maximum deviation of 0.1–0.2 Hz) and in the signal amplitude. The time delay of the ionospheric response lies in the range 40–60 min, while the relative disturbance in the electron density varies from 3% to 12%. Quasi-periodic variations in the Doppler frequency shift and in amplitude are caused by the generation and propagation of waves with 0.2–1.6 km/s speeds and 15–30 min periods. The 0.2–0.4 km/s speeds, as opposed to the 1.6 km/s speed, are regularly observed. The main directions of the future studies of how large-scale aperiodic and quasi-periodic disturbances manifest themselves in the ionosphere and the studies of how these disturbances affect the parameters of radio waves on remote radio paths are also discussed.

中文翻译：

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中低层电离层的大规模扰动伴随着 Sura 加热器的改造

我们简要描述了第一次（非专用）研究大尺度（约 1000 公里）非周期性和准周期性电离层中低层扰动的实验结果。列出了现代实验的主要结果。电离层下部大尺度（约 1000 公里）非周期性扰动和电离层中部准周期性扰动的多仪器放射物理观测，伴随着大功率（有效功率 40-95 MW）非平稳无线电的 Sura 加热器作用发射，是在 2017-2018 年使用部分反射和垂直/倾斜多径多频探测技术进行的。这些观测是在 2017-2018 年的四次供暖活动期间在哈尔科夫 VN Karazin 国立大学的天文台进行的。低电离层的非周期性扰动的延迟时间为 15-18 分钟，持续时间为 5-10 分钟。扰动伴随着加热器的开启和关闭。讨论了这些干扰的性质。中间电离层的主要影响包括以下几点。当有效辐射功率不低于 40-60 MW 时，多普勒频谱变得相当宽，并且在 Sura 开启后 40-60 分钟内，距离加热器 1000 公里的无线电路径上出现多径。电离层的周期性加热导致多普勒频移（最大偏差为 0.1–0.2 Hz）和信号幅度的周期性变化。电离层响应的时间延迟在 40-60 分钟的范围内，而电子密度的相对扰动在 3% 到 12% 之间变化。多普勒频移和幅度的准周期性变化是由速度为 0.2-1.6 公里/秒和周期为 15-30 分钟的波的产生和传播引起的。0.2-0.4 公里/秒的速度，而不是 1.6 公里/秒的速度，经常被观察到。还讨论了未来研究大尺度非周期性和准周期性扰动如何在电离层中表现出来的主要方向以及这些扰动如何影响远程无线电路径上无线电波参数的研究。