GRIB-API definition
| Name | Evaporation | Abbreviation | eva | Unit | kg m-2 | paramId: | 260259 |
UERRA details
| Definition | Moisture flux from the surface into the atmosphere. |
| Validity | accumulated (from the beginning of the forecast) |
| Comments | By model convention downward fluxes are positive. Positive evaporation represents condensation. |
WMO GRIB2 definition
| Parameter | ||
|---|---|---|
| Discipline | 0 | meteorological products |
| Parameter category | 1 | moisture |
| Parameter number | 79 | evaporation rate |
| Type of statistical processing | 1 | accumulated |
| Level | ||
|---|---|---|
| Type of first fixed surface | 1 | ground or water surface |
| Scale factor of first fixed surface | all bits to 1 | missing |
| Scaled value of first fixed surface | all bits to 1 | missing |
| Type of second fixed surface | all bits to 1 | missing |
| Scale factor of second fixed surface | all bits to 1 | missing |
| Scaled value of second fixed surface | all bits to 1 | missing |
7 Comments
Richard Mladek
Proposed parameter number equal to 79 (evaporation rate) follows the way the accumulated precipitation is defined (e.g. the cnmc uses such definition)
In WMO there is defined also Evaporation (parameter number 6) [kgm-2]. It would be analogical to our proposal but with one key less needed (Is it the official WMO recommendation to use as few keys as possible?).
Sebastien Villaume
we already have in the parameter database a parameter "e" evaporation with different units (m of water equivalent, which is a conversion factor of 10^^-3), paramid 182, and a bad grib2 discipline 192
Richard Mladek
We need the correct units..
My proposal is to follow the way how it is done in TIGGE/S2s for similar parameter total precipitation (228228)
Sebastien Villaume
yes, what I mean is that you can not call it "e" because it already exists, not that you should change your units.
Sebastien Villaume
the definition is similar to paramId 500039 but it is centre=cnmc
Regarding the shortname, it will not be easy, I see many evaporation paramters wrongly named or wrongly shortnamed in the parameter db
Sebastien Villaume
should we (Richard Mladek, Shahram Najm, Sebastien Villaume) meet to discuss this?
Shahram Najm
Yes please. Let's have a short meeting when Mladek is back