| | 89 | The albedo scheme in ORCHIDEE computes the temporal and spatial changes of the land-surface albedo for the near infrared, as well as for the visible range. Each surface type within the tiling scheme has a specific snow-free albedo. Whereas the albedo of bare soil is a fixed prescribed value, the albedo of vegetation is a combination of this bare soil albedo and the vegetation albedo, using Beer's law to determine the vegetated fraction. The albedo values of all tiles are weighted by their fractional cover and summed to a gridbox average albedo. |
| | 90 | |
| | 91 | In the case of snow, each surface type has additionally an initial albedo of snow prescribed. These values vary as a function of snow age and the amount of new snowfall. Snow density is prescribed, and the effects of aerosol deposition, grain type and snow water on snow albedo are not considered. |
| | 92 | |
| | 93 | The overall albedo is a combination of the fractional albedo of the snow coverage and the fractional albedo of vegetation. |
