GEOSCAN, résultats de la recherche


TitreEnhancement of solar wind low-energy energetic particles as precursor of geomagnetic disturbance in operational geomagnetic forecast
AuteurLam, H -L
SourceAdvances in Space Research vol. 43, 2009 p. 1299-1313,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100384
Documentpublication en série
Mediapapier; en ligne; numérique
Sujetsgéomagnétisme; champs géomagnétiques; variations géomagnétiques; levés magnétiques; orages magnétiques; interprétations magnétiques; géophysique
Illustrationsplots; histograms
ProgrammeTargeted Hazard Assessments in Northern Canada, Géoscience pour la sécurité publique
Résumé(disponible en anglais seulement)
A study of the relationship between solar wind low-energy energetic particles using data from the Electron, Proton, and Alpha Monitor (EPAM) onboard the Advanced Compositional Explorer spacecraft (ACE) and geomagnetic activity using data from Canadian magnetic observatories in Canada's polar cap, auroral zone, and subauroral zone was carried out for a period spanning 1997 - 2005. Full halo coronal mass ejections (CMEs) were used to gauge the initial particle enhancements and the subsequent geomagnetic activity. It was found that maximum geomagnetic activity is related to maximum particle enhancements in a non-linear fashion. Quadratic fit of the data results in expressions that can be easily used in an operational space weather setting to forecast geomagnetic disturbance quantitatively. A superposed epoch analysis shows increase in particle flux level starts hours before geomagnetic activity attains its peak, affirming the precursory nature of EPAM particles for the impending geomagnetic impact of CME. This can supplement the decision process in formulating geomagnetic warning after the launch of CME from the Sun but before the arrival of shock at Earth. The empirical relationships between solar wind low-energy energetic particles and geomagnetic activity revealed in this statistical study can be easily codified, and thus utilized in operational space weather forecast to appraise the geoeffectiveness of the CME and to provide a quantitative forecast for maximum geomagnetic activity in Canada's polar cap, auroral zone, and subauroral zone after the occurrence of a CME.