An empirical model of the variation of the solar Lyman-α spectral irradiance

Matthieu Kretzschmar (1) , Martin Snow (2) , Werner Curdt (3)

1 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
2 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
3 MPS - Max-Planck-Institut für Sonnensystemforschung

We propose a simple model that computes the spectral profile of the solar irradiance in the hydrogen Lyman alpha line, H Ly-α(121.567nm), from 1947 to present. Such a model is relevant for the study of many astronomical environments, from planetary atmospheres to interplanetary medium. This empirical model is based on the SOHO/SUMER observations of the Ly-α irradiance over Solar Cycle 23 and the Ly-α disk-integrated irradiance composite. The model reproduces the temporal variability of the spectral profile and matches the independent SORCE/SOLSTICE spectral observations from 2003 to 2007 with an accuracy better than 10%.

Domains: Geophysics [physics.geo-ph]; Space Physics [physics.space-ph]

Matthieu Kretzschmar, Martin Snow, Werner Curdt. An empirical model of the variation of the solar Lyman-α spectral irradiance. Geophysical Research Letters, 2018, 45 (5), pp.2138-2144. ⟨10.1002/2017GL076318⟩. ⟨insu-01719476⟩