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Ann. Geophys., 24, 129-151, 2006
www.ann-geophys.net/24/129/2006/
© European Geosciences Union 2006
From the Sun to the Earth: impact of the 27-28 May 2003 solar events on the magnetosphere, ionosphere and thermosphere
C. Hanuise1, J. C. Cerisier2, F. Auchère3, K. Bocchialini3, S. Bruinsma4, N. Cornilleau-Wehrlin5, N. Jakowski6, C. Lathuillère7, M. Menvielle2, J.-J. Valette8, N. Vilmer9, J. Watermann10, and P. Yaya8
1LPCE/CNRS, 3A avenue de la Recherche Scientifique, 45071 Orléans Cedex, France
2CETP/CNRS, 4 avenue de Neptune, 94107 St Maur des Fossés Cedex, France
3IAS, Bâtiment 121, Université Paris Sud 11 – CNRS, 91405 Orsay Cedex, France
4CNES, Département de Géodésie Spatiale, 31055 Toulouse Cedex 4, France
5CETP/IPSL, 10-12 avenue de l’Europe, 78140 Vélizy-Villacoublay, France
6Deutsches Zentrum für Luft und Raumfahrt, Kalkhorstweg 53, 17235 Neustrelitz, Germany
7LPG, Bâtiment D de Physique, BP 53, 38041 St Martin d’Hères Cedex 9, France
8CLS, 8-10 rue Hermès, 31520 Ramonville Saint-Agne, France
9LESIA, Observatoire de Paris, 5 place Jules Jansen, 92195 Meudon Cedex, France
10Danish Meteorological Institute, Lyngbyvej 100, 2100 Copenhagen, Denmark
Abstract. During the last week of May 2003, the solar active region AR 10365 produced
a large number of flares, several of which were accompanied by Coronal Mass
Ejections (CME). Specifically on 27 and 28 May three halo CMEs were observed
which had a significant impact on geospace. On 29 May, upon their arrival at
the L1 point, in front of the Earth's magnetosphere, two interplanetary
shocks and two additional solar wind pressure pulses were recorded by the
ACE spacecraft. The interplanetary magnetic field data showed the clear
signature of a magnetic cloud passing ACE. In the wake of the successive
increases in solar wind pressure, the magnetosphere became strongly
compressed and the sub-solar magnetopause moved inside five Earth radii. At
low altitudes the increased energy input to the magnetosphere was
responsible for a substantial enhancement of Region-1 field-aligned currents.
The ionospheric Hall currents also intensified and the entire high-latitude
current system moved equatorward by about 10°. Several substorms
occurred during this period, some of them - but not all - apparently
triggered by the solar wind pressure pulses. The storm's most notable
consequences on geospace, including space weather effects, were (1) the expansion
of the auroral oval, and aurorae seen at mid latitudes, (2) the significant
modification of the total electron content in the sunlight high-latitude
ionosphere, (3) the perturbation of radio-wave propagation manifested by HF
blackouts and increased GPS signal scintillation, and (4) the heating of the
thermosphere, causing increased satellite drag. We discuss the reasons why
the May 2003 storm is less intense than the October-November 2003 storms,
although several indicators reach similar intensities.
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