On the benefit of using spectral albedo and light penetration depth in detailed snowpack simulations

Monday, 14 December 2015
Poster Hall (Moscone South)
Marie Dumont1, Matthieu Lafaysse1,2, Ghislain Picard3,4, Laurent Arnaud3, Quentin Libois3,4 and Samuel Morin1,2, (1)CNRM-GAME, Toulouse Cedex 01, France, (2)CEN / Météo-France, Saint Martin D'Here, France, (3)LGGE Laboratoire de Glaciologie et Géophysique de l’Environnement, Saint Martin d'Hères, France, (4)UJF/LGGE Laboratoire de Glaciologie et Géophysique de l’Environnement, Grenoble, France
The detailed snowpack model SURFEX/ISBA-Crocus is used for a wide range of applications such as avalanche hazard risk forecast, mountain hydrology and climatology. Recently, a spectral two-stream radiative scheme (TARTES, Libois et al., 2013) has been implemented in Crocus in replacement of the original semi-empirical parameterizations of albedo and solar radiation absorption. The effect of the spectral repartition of the diffuse/direct incident solar radiation, of the sun zenith angle and of the physical and chemical properties of every snow layers are thus physically taken into account in the computation of the solar radiation penetration and absorption in the snowpack. Crocus simulations with various options ranging from the original version to the full radiative transfer for both the snowpack and the atmosphere are compared during one winter season at Col de Porte Site, Chartreuse, France. The detailed benefits of using a full radiative transfer scheme are evaluated with respect to snow physical properties, spectral albedo measurements. The impacts of the physically-based radiative scheme on the snow temperature profiles and metamorphism are investigated.