Service International des Indices Géomagnétiques
International Service of Geomagnetic Indices

Solar Flare Effects (SFE)

Available from 1970 onwards
Type of event Solar Flare Effects when solar flare points towards the Earth
Purpose To provide the reference list of sudden perturbation in geomagnetic elements that follows the eruption of a solar flare.
Determination SFE are usually noticed as the signature on magnetograms at low and mid-latitude stations of an increase in the intensity of the Solar-quiet current system. The events are characterised by visual analysis of conditions on the Sun. When a solar flare points towards the Earth, SFE events occur.
Preliminary lists of SFE events are compiled on the basis of reports made by observatories by morphological inspection of their magnetograms.
Definitive lists of SFE events are based on reports from observatories in response to a checking list sent by Observatori de l'Ebre, Spain.
ISGI Collaborating Institute Observatori de l'Ebre, Spain
IAGA endorsed IAGA Bulletin 37, 1975, p. 130, resolution 6
Historical references • International Association of Geomagnetism and Aeronomy (1959) - Provisional atlas of rapid variations in: Annals of the International Geophysical Year, vol. II B, pp. 668-709, Pergamon, London.
• Curto, J.J., C. Mazaudier, J.M. Torta, and M. Menvielle (1994) - Study of solar flare effects at Ebre: regular and reversal sfe, statistical analysis (1953 to 1985) and a global case study, J. Geophys. Res., 99, 3945-3954, doi:10.1029/93JA02270.