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


Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

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

Supplementary files

Supplementary Files
Action
1. JATS XML

Copyright (c) 2017 Springer Science+Business Media, LLC, part of Springer Nature