Abstract : The solar irradiance in the UV is a key ingredient in space weather applications; however, because of the lack of continuous and long-term observations, various indices are still used today as surrogates for the solar spectral irradiance. Aims. As an alternative to current spectrometers we use a few radiometers with properly chosen passbands and reconstruct the solar spectral irradiance from their outputs. The feasibility of such a reconstruction is justified by the high redundancy in the spectral variability. Methods. Using a multivariate statistical approach, we first compared six years of daily-averaged UV spectra and a selection of passbands (from existing radiometers) and solar indices. This leads to a strategy for defining those passbands that are most appropriate for reconstructing the spectrum. Results. With four passdbands chosen from already existing instruments, we reconstruct the UV spectrum with a relative error of about 20%. Better performance is achieved with a combination of passbands than with a combination of indices.
https://hal.archives-ouvertes.fr/hal-00592261
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Submitted on : Monday, January 11, 2016 - 10:12:16 AM Last modification on : Saturday, December 12, 2020 - 12:10:03 PM Long-term archiving on: : Tuesday, April 12, 2016 - 11:08:05 AM
G. Cessateur, Thierry Dudok de Wit, Matthieu Kretzschmar, J. Lilensten, Jean-François Hochedez, et al.. Monitoring the solar UV irradiance spectrum from the observation of a few passbands. Astronomy and Astrophysics - A&A, EDP Sciences, 2011, 528, A68 (9 p.). ⟨10.1051/0004-6361/201015903⟩. ⟨hal-00592261⟩