Predictions of the arrival time of Coronal Mass Ejections at 1AU: an analysis of the causes of errors - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Annales Geophysicae Année : 2004

Predictions of the arrival time of Coronal Mass Ejections at 1AU: an analysis of the causes of errors

Résumé

Three existing models of Interplanetary Coronal Mass Ejection (ICME) transit between the Sun and the Earth are compared to coronagraph and in situ observations: all three models are found to perform with a similar level of accuracy (i.e. an average error between observed and predicted 1AU transit times of approximately 11h). To improve long-term space weather prediction, factors influencing CME transit are investigated. Both the removal of the plane of sky projection (as suffered by coronagraph derived speeds of Earth directed CMEs) and the use of observed values of solar wind speed, fail to significantly improve transit time prediction. However, a correlation is found to exist between the late/early arrival of an ICME and the width of the preceding sheath region, suggesting that the error is a geometrical effect that can only be removed by a more accurate determination of a CME trajectory and expansion. The correlation between magnetic field intensity and speed of ejecta at 1AU is also investigated. It is found to be weak in the body of the ICME, but strong in the sheath, if the upstream solar wind conditions are taken into account.

Key words. Solar physics, astronomy and astrophysics (flares and mass ejections) ? Interplanetary physics (interplanetary magnetic fields; sources of the solar wind)
Fichier principal
Vignette du fichier
angeo-22-661-2004.pdf (906.98 Ko) Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Loading...

Dates et versions

hal-00317248 , version 1 (18-06-2008)

Identifiants

  • HAL Id : hal-00317248 , version 1

Citer

M. Owens, P. Cargill. Predictions of the arrival time of Coronal Mass Ejections at 1AU: an analysis of the causes of errors. Annales Geophysicae, 2004, 22 (2), pp.661-671. ⟨hal-00317248⟩

Collections

INSU EGU
150 Consultations
75 Téléchargements

Partager

Gmail Facebook X LinkedIn More