PreprintArticleVersion 1Preserved in Portico This version is not peer-reviewed
Ionospheric Absorption Variation Based on Ionosonde and Riometer Data and the NOAA D-RAP Model over Europe During Intense Solar Flares in September, 2017
Version 1
: Received: 20 September 2024 / Approved: 23 September 2024 / Online: 23 September 2024 (12:16:33 CEST)
How to cite:
Barta, V.; Bozóki, T.; Süle, D. P.; Kouba, D.; Mielich, J.; Raita, T.; Buzás, A. Ionospheric Absorption Variation Based on Ionosonde and Riometer Data and the NOAA D-RAP Model over Europe During Intense Solar Flares in September, 2017. Preprints2024, 2024091700. https://doi.org/10.20944/preprints202409.1700.v1
Barta, V.; Bozóki, T.; Süle, D. P.; Kouba, D.; Mielich, J.; Raita, T.; Buzás, A. Ionospheric Absorption Variation Based on Ionosonde and Riometer Data and the NOAA D-RAP Model over Europe During Intense Solar Flares in September, 2017. Preprints 2024, 2024091700. https://doi.org/10.20944/preprints202409.1700.v1
Barta, V.; Bozóki, T.; Süle, D. P.; Kouba, D.; Mielich, J.; Raita, T.; Buzás, A. Ionospheric Absorption Variation Based on Ionosonde and Riometer Data and the NOAA D-RAP Model over Europe During Intense Solar Flares in September, 2017. Preprints2024, 2024091700. https://doi.org/10.20944/preprints202409.1700.v1
APA Style
Barta, V., Bozóki, T., Süle, D. P., Kouba, D., Mielich, J., Raita, T., & Buzás, A. (2024). Ionospheric Absorption Variation Based on Ionosonde and Riometer Data and the NOAA D-RAP Model over Europe During Intense Solar Flares in September, 2017. Preprints. https://doi.org/10.20944/preprints202409.1700.v1
Chicago/Turabian Style
Barta, V., Tero Raita and Attila Buzás. 2024 "Ionospheric Absorption Variation Based on Ionosonde and Riometer Data and the NOAA D-RAP Model over Europe During Intense Solar Flares in September, 2017" Preprints. https://doi.org/10.20944/preprints202409.1700.v1
Abstract
A novel method has been developed based on the amplitude data of the EM waves measured by Digisondes to calculate and investigate the relative ionospheric absorption changes. The effect of 13 solar flares (> C4.8) that occurred between 06:00 and 16:30 UT from 04 to 10 September 2017 have been studied at three European Digisonde stations (Juliusruh (54.63° N, 13.37° E), Průhonice (49.98° N, 14.55° E) and San Vito (40.6° N, 17.8° E)). Present study compares the results of the amplitude method with the absorption changes measured by the Finnish Riometer Network and determined by the NOAA D-RAP model during the same events. The X-class flares caused 1.5–2.5 dB attenuation at 30–32.5 MHz based on riometer data, while the absorption changes were between 10 and 15 dB in the 2.5–4.5 MHz frequency range according to the amplitude data. The impact caused by the energetic particles after the solar flares are clearly seen in the riometer data, while it can be observed only at Juliusruh (~55°) at some certain cases among the Digisonde stations. Comparing the results of the amplitude method with the D-RAP model it seems evident that the observed values exceed the values given by the model both at 2.5 MHz and at 4 MHz almost always during the investigated period. According to the comparison between the riometer data with the D-RAP, the model underestimates the values obtained from the riometers during the X-class solar flares, while it overestimates the caused impact during the particle events.
Keywords
space weather; solar flare; ionosphere; ionospheric absorption; ionosonde data; HF radio wave absorption; radio fade-out; riometer; D-RAP model
Subject
Environmental and Earth Sciences, Space and Planetary Science
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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