Statistical representation of mountain shading

R. Essery (1)

1 Centre for Glaciology

Shadows cast by the mountains themselves have a strong influence on the surface energy balance of mountainous regions. If the influence of shadows is to be included on sub-grid scales in a surface energy balance model, a statistical representation has to be used. Slope components calculated from digital elevation models of areas in North Wales and the French Alps are found to have double-exponential distributions. From this result, expressions are developed for the fractions of the areas that will be either self-shaded or shaded by remote topography as functions of solar elevation and time of day. These expressions are in good agreement with results from a terrain shading model.

Keywords: solar radiation, topography, surface energy balance, statistical parameterisation

Domaines: Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

R. Essery. Statistical representation of mountain shading. Hydrology and Earth System Sciences Discussions, 2004, 8 (6), pp.1047-1052. ⟨hal-00304980⟩