Galactic X-ray sources and the ionospheric D region

Nature ◽  
1975 ◽  
Vol 257 (5521) ◽  
pp. 34-35 ◽  
Author(s):  
HAYDEE KARSZENBAUM ◽  
DOMINGO A. GAGLIARDINI
Keyword(s):  
X Ray ◽  
D Region

scholarly journals Case study of the mesospheric and lower thermospheric effects of solar X-ray flares: coupled ion-neutral modelling and comparison with EISCAT and riometer measurements

2008 ◽  
Vol 26 (8) ◽  
pp. 2311-2321 ◽  
Author(s):  
C.-F. Enell ◽  
P. T. Verronen ◽  
M. J. Beharrell ◽  
J. P. Vierinen ◽  
A. Kero ◽  
...  
Keyword(s):  
Solar Proton ◽  
Spectral Irradiance ◽  
Cluster Ions ◽  
Ion Chemistry ◽  
Density Profiles ◽  
X Ray ◽  
Noise Absorption ◽  
D Region ◽  
Electron Density Profiles ◽  
Cosmic Noise

Abstract. Two case studies of upper mesospheric and lower thermospheric (UMLT) high-latitude effects of solar X-ray flares are presented. Sodankylä Ion-neutral Chemistry Model (SIC) electron density profiles agree with D-region EISCAT and riometer observations, provided that the profiles of the most variable ionisable component, nitric oxide, are adjusted to compensate for NOx production during preceding geomagnetically active periods. For the M6-class flare of 27 April 2006, following a quiet period, the agreement with cosmic noise absorption observed by the Sodankylä riometers was within reasonable limits without adjustment of the [NO] profile. For the major (X17-class) event of 28 October 2003, following high auroral activity and solar proton events, the NO concentration had to be increased up to on the order of 108 cm−3 at the D-region minimum. Thus [NO] can in principle be measured by combining SIC with observations, if the solar spectral irradiance and particle precipitation are adequately known. As the two case events were short and modelled for high latitudes, the resulting neutral chemical changes are insignificant. However, changes in the model ion chemistry occur, including enhancements of water cluster ions.

scholarly journals GNSS and SAR Signal Delay in Perturbed Ionospheric D-Region During Solar X-Ray Flares

2020 ◽  
Vol 17 (7) ◽  
pp. 1198-1202 ◽  
Author(s):  
Aleksandra Nina ◽  
Giovanni Nico ◽  
Oleg Odalovic ◽  
Vladimir M. Cadez ◽  
Miljana Todorovic Drakul ◽  
...  
Keyword(s):  
Signal Delay ◽  
X Ray ◽  
D Region

Possibility of continuous monitoring of celestial X-ray sources through their ionization effects in the nocturnal D-region ionosphere

1972 ◽  
Vol 17 (2) ◽  
pp. 409-425 ◽  
Author(s):  
D. P. sharma ◽  
A. K. Jain ◽  
S. C. Chakravarty ◽  
K. Kasturirangan ◽  
K. R. Ramanathan ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
X Ray ◽  
D Region

D-region recombination coefficients and the short wavelength X-ray flux during a solar flare

1973 ◽  
Vol 21 (3) ◽  
pp. 367-375 ◽  
Author(s):  
S. Ananthakrishnan ◽  
M.A. Abdu ◽  
L.R. Piazza
Keyword(s):  
Solar Flare ◽  
Short Wavelength ◽  
X Ray ◽  
D Region

scholarly journals Novel Modelling Approach for Obtaining the Parameters of Low Ionosphere under Extreme Radiation in X-Spectral Range

2021 ◽  
Vol 11 (23) ◽  
pp. 11574
Author(s):  
Vladimir A. Srećković ◽  
Desanka M. Šulić ◽  
Veljko Vujčić ◽  
Zoran R. Mijić ◽  
Ljubinko M. Ignjatović
Keyword(s):  
Spectral Range ◽  
Low Frequency ◽  
Lower Ionosphere ◽  
Simple Expression ◽  
Spectral Lines ◽  
Spectral Radiation ◽  
X Ray ◽  
Reflection Height ◽  
D Region ◽  
Modelling Approach

Strong radiation from solar X-ray flares can produce increased ionization in the terrestrial D-region and change its structure. Moreover, extreme solar radiation in X-spectral range can create sudden ionospheric disturbances and can consequently affect devices on the terrain as well as signals from satellites and presumably cause numerous uncontrollable catastrophic events. One of the techniques for detection and analysis of solar flares is studying the variations in time of specific spectral lines. The aim of this work is to present our study of solar X-ray flare effects on D-region using very low-frequency radio signal measurements over a long path in parallel with the analysis of X-spectral radiation, and to obtain the atmospheric parameters (sharpness, reflection height, time delay). We introduce a novel modelling approach and give D-region coefficients needed for modelling this medium, as well as a simple expression for electron density of lower ionosphere plasmas. We provide the analysis and software on GitHub.

D-region extraionization and solar X-ray flux derived from SPA and SES measurements

1972 ◽  
Vol 34 (3) ◽  
pp. 543-547
Author(s):  
R Barletti ◽  
G.L Tagliaferri
Keyword(s):  
X Ray ◽  
D Region
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