Solar wind and geomagnetism: toward a standard classification of geomagnetic activity from 1868 to 2009

Jean-Louis Zerbo (1, 2) , Christine Amory-Mazaudier (1) , Frédéric Martial Ouattara (3) , J.D. Richardson (4)

1 LPP - Laboratoire de Physique des Plasmas
2 UNB - Université Nazi Boni (Bobo-Dioulasso)
3 ENSK - École Normale Supérieure - Koudougou
4 CSR - Center for Space Research [Cambridge]

We examined solar activity with a large series of geomagnetic data from 1868 to 2009. We have revisited the geomagnetic activity classification scheme of Legrand and Simon (1989) and improve their scheme by lowering the minimum Aa index value for shock and recurrent activity from 40 to 20 nT. This improved scheme allows us to clearly classify about 80% of the geomagnetic activity in this time period instead of only 60% for the previous Legrand and Simon classification.

Mots clés: Geomagnetism; paleomagnetism; Time variations; secular and long term

Domaines: Climatologie; Milieux et Changements globaux

Jean-Louis Zerbo, Christine Amory-Mazaudier, Frédéric Martial Ouattara, J.D. Richardson. Solar wind and geomagnetism: toward a standard classification of geomagnetic activity from 1868 to 2009. Annales Geophysicae, 2012, pp.1-6. ⟨10.5194/angeo-30-421-2012⟩. ⟨hal-00966389⟩