Geoscience Reference
In-Depth Information
- fraction of sand, clay and limestone present in the soil,
- soil depth;
ii) parameters characterizing the vegetation:
- vegetation fraction (veg= 1 - fraction of bare soil),
- the leaf area index (LAI),
- the normalized difference vegetation index (NDVI),
- the minimal stomatal resistance (Rsmin),
- the roughness length (Z
0
, which is measured and expressed as a function of
vegetation cover);
iii) Parameters characterizing both soil and vegetation:
- albedo and emissivity (both expressed as a function of the LAI).
4.4.2.
Ocean surface
The roughness length is expressed by the Charnock formula for Z0, showing a
quadratic dependence on the friction velocity.
4.4.3.
Observations
Figure 4.6.
The different elements of the WMOs global observation system
Operational numerical prediction uses several types of conventional
meteorological observations; however, nowadays, more and more observations are
produced by satellite and are available in real time (see Figure 4.6).
