Review on the solar spectral variability in the EUV for space weather purposes

L. Lilensten (1, 2) , Thierry Dudok de Wit (3) , L. Kretzschmar (4) , Fredéric Amblard (5) , S. Moussaoui (6) , J. Aboudarham (7) , F Auchère (8)

1 LPG - Laboratoire de Planétologie et Géodynamique [UMR 6112]
2 UJF - Université Joseph Fourier - Grenoble 1
3 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
4 SIDC - Solar Influences Data Analysis Center [Brussels]
5 GIPSA-SIGMAPHY - GIPSA - Signal Images Physique
6 Institut de Recherche en Communication et Cybernétique de Nantes
7 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
8 IAS - Institut d'astrophysique spatiale

The solar XUV-EUV flux is the main energy source in the terrestrial diurnal thermosphere: it produces ionization, dissociation, excitation and heating. Accurate knowledge of this flux is of prime importance for space weather. We first list the space weather applications that require nowcasting and forecasting of the solar XUV-EUV flux. We then review present models and discuss how they account for the variability of the solar spectrum. We show why the measurement of the full spectrum is difficult, and why it is illusory to retrieve it from its atmospheric effects. We then address the problem of determining a set of observations that are adapted for space weather purposes, in the frame of ionospheric studies. Finally, we review the existing and future space experiments that are devoted to the observation of the solar XUV-EUV spectrum.

Mots clés: physics; astro-; Ionosphere (Modeling and forecasting; Solar; radiation and cosmic ray effects) – Solar physics; astronomy (Ultraviolet emissions)

Domaines: Physique de l'espace [physics.space-ph]; Astrophysique stellaire et solaire [astro-ph.SR]

L. Lilensten, Thierry Dudok de Wit, L. Kretzschmar, Fredéric Amblard, S. Moussaoui, et al.. Review on the solar spectral variability in the EUV for space weather purposes. Annales Geophysicae, 2008, 26 (2), pp.269-279. ⟨10.5194/angeo-26-269-2008⟩. ⟨insu-01539780⟩