| Titre | On the prediction of relativistic electron fluence based on its relationship with geomagnetic activity over a solar cycle
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| Auteur | Lam, H -L |
| Source | Journal of Atmospheric and Solar-Terrestrial Physics vol. 66, 2004 p. 1703-1714, https://doi.org/10.1016/j.jastp.2004.08.002 |
| Année | 2004 |
| Séries alt. | Commission géologique du Canada, Contributions aux publications extérieures 2001050 |
| Éditeur | Elsevier BV |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.jastp.2004.08.002 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Sujets | variations géomagnétiques; géomagnétisme; champs géomagnétiques; cycles solaires; zone aurorale; orages magnétiques; tempêtes; satellites; géologie extraterrestre; géophysique |
| Illustrations | graphiques; tableaux |
| Diffusé | 2004 12 01 |
| Résumé | (disponible en anglais seulement)
A study has been carried out to determine the relationship between high energy relativistic (>2 MeV) electron fluence and auroral zone geomagnetic activity for
a solar cycle. Data for 1987-1997, spanning Solar Cycle 22, were used in the study. The relativistic electron fluence data were based on fluxes observed by the GOES geosynchronous satellites. The geomagnetic data were the DRX indices derived from a
Canadian magnetic observatory located in the auroral zone at Fort Churchill, near the footprint of field lines passing through geostationary satellites. This work, based on data from a solar cycle, confirms earlier findings using limited data from
segments of a solar cycle of enhancement in fluence 2-3 days after increases in geomagnetic activity, and shows the cycle dependence of fluence with respect to geomagnetic activity. This study underlines the influence of recurrent coronal holes on
fluence level as well as the possible role of Pc5 magnetic pulsations as an electron acceleration mechanism, and highlights the predictability of fluence from ground geomagnetic data. A fluence prediction algorithm can now solely be based on derived
expressions relating fluence and DRX. Thus, a simple fluence prediction scheme can easily be implemented to provide a 2-3 day advance warning of space weather conditions hazardous to geosynchronous satellites, since during days of high fluence, the
likelihood of internal charging in a satellite is high, with possible discharges that could result in satellite operational anomalies. For verification purpose, daily values of fluence for 1997-2000 and for January 1994 were postcast using the
derived expressions. The postcast values were validated, and the results give credence to the fluence prediction scheme. |
| GEOSCAN ID | 212632 |
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