Abstract—

A solar eclipse (SE) provides a researcher with a rare opportunity to follow the dynamics of the Earth’s system (its shells)—the atmosphere, the ionosphere, and the magnetosphere—and variations in the geophysical fields over an interval of a few hours. Different solar eclipses induce significantly different disturbances in this system. The parameters of these disturbances depend on the onset time of a solar eclipse, the state of space weather, the season, the solar cycle phase, the geographic coordinates, and the degree of the solar disk occultation during a solar eclipse. It should be kept in mind that each of the SEs exhibits its own individual characteristics. The purpose of this paper is to analyze the results of ionosonde observations of the ionospheric disturbances accompanying the SE above the city of Kharkiv on June 10, 2021. At the city of Kharkiv, the maximal observed magnitude of the SE was М_max ≈ 0.11 (more precisely, 0.112) and the relative area of the solar disk occultation was А_max ≈ 4.4%. The eclipse started at 10:42 UT (13:42 LT) and ended at 12:12 UT (15:12 LT). The maximal magnitude was observed at 11:28 UT (14:28 LT). To study the features of variations in the virtual heights and the frequencies, we used a digital ionosonde located at the Radio Physical Observatory of the V. N. Karazin Kharkiv National University. The analysis of the space weather showed that, during the SE, as well as at the reference time intervals on June 6 and 9, 2021, the space weather conditions were favorable for observing wave disturbances, which is evidenced by the index value K_p ≈ 0.3. The frequency and altitude characteristics of the ionosphere obtained by vertical sounding were analyzed, and the features of the ionospheric processes, which accompanied the partial SE but were absent on the reference day, were determined. During the SE, wave activity in the ionosphere became stronger. The wave trains, which were observed at an altitude of the F₂ layer maximum, had periods of 5 and 14 min, while the relative amplitudes of oscillations in the electron density were 0.6 and 1.25%, respectively. At an altitude of 240 km, the relative amplitude of waves with a period of ~14 min increased by 3%. The 14-min period pertains to the atmospheric gravitaty waves, while the 5-min period pertains to the waves of electromagnetic nature. A sharp and considerable increase (from 380 to 560 km) in the virtual height of the radio wave reflection from the F₂ region was observed close to the moment of the greatest SE magnitude. A weak decrease (by less than 3.3%) in the electron density, which lagged behind the maximal eclipse magnitude by 12.5 min, was detected. The rates of the electron loss (1.33 × 10^–3 s^–1) and the ion production (3 × 10⁸ m^–3s^–1) were estimated.

中文翻译：

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2021 年 6 月 10 日哈尔科夫上空日偏食期间的电离层过程

摘要-

日食 (SE) 为研究人员提供了一个难得的机会来跟踪地球系统（其外壳）的动态——大气、电离层和磁层——以及地球物理场在几个小时内的变化。不同的日食会在该系统中引起明显不同的干扰。这些扰动的参数取决于日食的开始时间、空间天气状态、季节、太阳周期阶段、地理坐标以及日食期间太阳盘掩星的程度。应该记住，每个 SE 都表现出自己的个性。本文的目的是分析 2021 年 6 月 10 日在哈尔科夫市上空伴随 SE 的电离层扰动的电离探空仪观测结果。М _max  ≈ 0.11（更准确地说是 0.112），太阳盘掩星的相对面积为А _max  ≈ 4.4%。日食始于 10:42 UT（13:42 LT），结束于 12:12 UT（15:12 LT）。在 11:28 UT (14:28 LT) 观察到最大幅度。为了研究虚拟高度和频率变化的特征，我们使用了位于 VN 卡拉津哈尔科夫国立大学无线电物理天文台的数字电离探测器。空间天气分析表明，在 SE 期间以及 2021 年 6 月 6 日至 9 日的参考时间间隔内，空间天气条件有利于观测波浪扰动，指标值K _{p证明了这一点} ≈ 0.3。分析了垂直测深获得的电离层频率和高度特征，确定了伴随部分SE但在参考日不存在的电离层过程的特征。在 SE 期间，电离层中的波活动变得更强。在F ₂高度观察到的波列层最大值，周期为 5 分钟和 14 分钟，而电子密度振荡的相对幅度分别为 0.6% 和 1.25%。在海拔 240 km 处，周期约为 14 min 的波的相对振幅增加了 3%。14 分钟周期属于大气引力波，而 5 分钟周期属于电磁波。在接近最大 SE 震级的时刻，观察到来自F ₂区域的无线电波反射的虚拟高度急剧而显着增加（从 380 公里到 560 公里） 。检测到电子密度的微弱下降（小于 3.3%），比最大日食幅度落后 12.5 分钟。电子损失率 (1.33 × 10 ^–3 s ^–1) 和离子产生量 (3 × 10 ⁸ m ^–3 s ^–1 ) 进行了估计。