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| Definition | Liquid non-frozen volumetric soil moisture on a soil layer. |
| Validity | instantaneous |
| Comment | Sea points should be set as missing values. To interpret soil moisture and to compare different models the Soil Wetness Index (SWI) is used:
SWI = (soil_moisture - wilting_point) / (field_capacity - wilting_point).
Field capacity corresponds to the maximum value that the model can sustain without precipitation for more than a few hours. The vegetated fraction of the soil evaporates at the maximum rate for soil moisture larger than field capacity and stops evaporating below the permanent wilting point, with a continuous variation between the two extremes.
All Partners are asked to provide the wilting point and the field capacity for each grid point. |
Soil layers must always start from 1 (0 soil level is the surface by default which is not encoded). |
WMO GRIB2 definition
| Parameter |
|---|
| Discipline | 2 | land surface products |
| Parameter category | 3 | soil products
|
| Parameter number | 10 | liquid volumetric soil moisture (non-frozen) |
(Meteo-France only) |
|---|
| Type of first fixed surface |
106 | depth below land surface (m)| 151 | soil level** |
| Scale factor of first fixed surface | 0 | |
| Scaled value of first fixed surface | 0 |
| /1/2/3/.../X-1 | n-1 for the nth soil layer |
|
| Type of second fixed surface |
106 or 167***
| "depth below land surface (m)" or "bottom of root zone"**| 151 | soil level* |
| Scale factor of second fixed surface |
1 or all bits to 1*** | (cm) or missing***| 0 | |
| Scaled value of second fixed surface |
value in cm or all bits to 1*** | 1 or missing*** | *** valid for the 3rd Meteo-France layer (from surface to the bottom of root zone)
| 1/2/3/.../X | n for the nth soil layer |
**newly approved level type (WMO release in May 2016)