| Titre | Data-based optimization of a simple shortwave fadeout absorption model |
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| Auteur | Fiori, R A D ;
Chakraborty, S; Nikitina, L |
| Source | Journal of Atmospheric and Solar-Terrestrial Physics vol. 230, 105843, 2022 p. 1-11, https://doi.org/10.1016/j.jastp.2022.105843  Accès ouvert |
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| Année | 2022 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210218 |
| Éditeur | European Geophysical Union |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.jastp.2022.105843 |
| Media | papier; en ligne; numérique |
| Formats | pdf; html |
| Province | Canada; Colombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon;
Nunavut |
| SNRC | 1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560 |
| Sujets | établissement de modèles; modèles; ionosphère; variations solaires; absorption; analyses statistiques; Aléas naturels; Méthodologie; Communications; géophysique; Sciences et technologie; Nature et
environnement |
| Illustrations | cartes de localisation; tableaux; séries chronologiques; graphiques; graphiques en étoile; graphique à barres |
| Programme | Géoscience pour la sécurité publique Évaluation des risques de la météorologie spatiale |
| Diffusé | 2022 03 03 |
| Résumé | (disponible en anglais seulement)
Electron density enhancement caused by electromagnetic radiation emitted during a solar X-ray flare has the potential to increase high frequency (HF; 3-30 MHz)
absorption in the dayside D-region ionosphere, impacting shortwave radio signals by reducing the signal strength, a phenomenon commonly referred to as shortwave fadeout. Data-based optimization of a simple absorption model is performed incorporating
solar X-ray flux data and 30 MHz riometer data from stations distributed across Canada. In a single event study the data-based optimization model is shown to overestimate absorption by 1% for the duration of an X2.1 solar X-ray flare. This corrects
an underestimation by the NOAA D-region Absorption Prediction (D-RAP) model. In a statistical study, based on 87 events, data-based optimization performed on an event-by-event basis showed excellent overall agreement between measured and modelled
data: the Pearson correlation coefficient was R=0.88, and the slope of the best-fit line to the data was m=0.91. A generalized model was developed using data from all 87 events collectively. Although good agreement was found between the measured and
modelled data sets, correlation and slope were slightly reduced to R=0.75 and m=0.80. Model accuracy is characterized by prediction efficiency (PE) which peaked at PE=0.78 for the event-by-event evaluation and PE=0.48 for the collective data set. The
results of this study highlight the advantages of data-based optimization in modelling absorption due to shortwave fadeout. |
| Sommaire | (Résumé en langage clair et simple, non publié)
La météo spatiale fait référence aux conditions dynamiques du soleil et de l'environnement spatial qui peuvent influer sur les infrastructures
essentielles. RNCan exploite le Centre canadien de météo spatiale et étudie les effets de la météo spatiale sur les systèmes d'alimentation électrique, les pipelines, les satellites, les installations de communications radio et le FGISM pour aider
l'industrie canadienne à comprendre et à atténuer les effets de la météo spatiale. Cet article présente un modèle simple, développé à partir d'un réseau canadien d'instruments riomètres, de l'absorption des signaux radio causés par une éruption
solaire. |
| GEOSCAN ID | 328728 |
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