Impact of a Strong Magnetic Storm and Two X-Ray Flares on the Ionospheric HF Channel in the Summer Solstice of 2015 According to Oblique Sounding in the Eurasian Region
- Authors: Uryadov V.P.1,2, Kolchev A.A.3, Vertogradov G.G.4, Vybornov F.I.1, Egoshin I.A.5, Sklyarevsky M.S.4, Shumaev V.V.6, Chernov A.G.6
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Affiliations:
- Radiophysical Research Institute of the NI. Lobachevsky State University of Nizhny Novgorod
- Polyot, a scientific and production enterprise
- Kazan (Volga) Federal University
- Southern Federal University
- Mari El State University
- SITKOM, LLC
- Issue: Vol 60, No 5 (2017)
- Pages: 355-373
- Section: Article
- URL: https://journal-vniispk.ru/0033-8443/article/view/243797
- DOI: https://doi.org/10.1007/s11141-017-9806-y
- ID: 243797
Cite item
Abstract
We present the results of observations of the impact a strong magnetic storm and two X-ray flares in the summer solstice of 2015 on the HF signal characteristics during oblique sounding of the ionosphere in the Eurasian region. It was found that the negative phase of the magnetic storm led to a strong degradation of the ionospheric channel, up to a long blackout on the paths adjacent to the subauroral latitudes. On the midlatitude paths, a decrease in the maximum observable frequency of the F layer reached 50% with respect to the average values for an undisturbed ionosphere. The propagation velocity of the negative phase of a disturbance from the subauroral to the midlatitude ionosphere is determined (it is equal to about 100 m/s). It is shown that during a magnetic storm the least observable frequency and the average signal-to-noise ratio for the propagation mode via the sporadic Es layer correlate well with the auroral AE index. Anomalous signals were detected in the main phase of the magnetic storm on the Cyprus—Rostov-on-Don path when a chirp ionosonde–radio direction finder was operated in the over-the-horizon HF radar mode. On the basis of modeling and comparison with experimental data, it is shown that the anomalous signals are due to scattering of radio waves by small-scale irregularities located in the subauroral ionospheric F region.
About the authors
V. P. Uryadov
Radiophysical Research Institute of the NI. Lobachevsky State University of Nizhny Novgorod; Polyot, a scientific and production enterprise
Author for correspondence.
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Nizhny Novgorod; Nizhny Novgorod
A. A. Kolchev
Kazan (Volga) Federal University
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Kazan
G. G. Vertogradov
Southern Federal University
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Rostov-on-Don
F. I. Vybornov
Radiophysical Research Institute of the NI. Lobachevsky State University of Nizhny Novgorod
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Nizhny Novgorod
I. A. Egoshin
Mari El State University
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Ioshkar-Ola
M. S. Sklyarevsky
Southern Federal University
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Rostov-on-Don
V. V. Shumaev
SITKOM, LLC
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Ioshkar-Ola
A. G. Chernov
SITKOM, LLC
Email: uryadov.vp@nirfi.unn.ru
Russian Federation, Ioshkar-Ola
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