Below is a list of all agreed upon parameters. Participating Centres are expected to produce output fields in GRIB2 data format and with consistent units. All units are defined by the WMO in the GRIB2 manual. For more information please refer to Guide to the WMO Table Driven Code Form.
For the actual availability of UERRA parameters from each model in MARS refer to the page Parameter availability.
Model level parameters
Output of analyses on (hybrid) model levels are stored up to a height of about 15km every six hours (at 00/06/12/18UTC).
Model level increases with height for MO and decreases for other models.
- COSMO: 1..40
- HARMONIE: 1..65
- MO: 1..63
| Name | Abbreviation | Unit |
| Cloud cover | ccl | % |
| Pressure | pres | Pa |
| Specific cloud liquid water content | clwc | kg kg-1 |
| Specific cloud ice water content | ciwc | kg kg-1 |
| Specific humidity | q | kg kg-1 |
| Temperature | t | K |
| U-velocity | u | m s-1 |
| V-velocity | v | m s-1 |
Pressure level parameters
Output of forecasts and analyses on pressure levels for defined time steps.
Pressure levels [hPa]:
1000, 975, 950, 925, 900, 875, 850, 825, 800, 750, 700, 600, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 20, 10
Time steps:
Analysis:
● Store analysis output in six hourly intervals (at 00/06/12/18UTC) for the Unified Model and Harmonie
● Store analysis output in hourly intervals for COSMO
Forecasts for all models:
● T+1,2,3,4,5,6,9,12,15,18,21,24,27,30 started at 00 UTC and 12 UTC
● T+1,2,3,4,5,6 started at 06 UTC and 18 UTC
| Name | Abbreviation | Unit |
| Cloud cover | ccl | % |
| Geopotential | z | m2 s-2 |
| Specific cloud liquid water content | clwc | kg kg-1 |
| Specific cloud ice water content | ciwc | kg kg-1 |
| Relative humidity | r | % |
| Temperature | t | K |
| U-velocity | u | m s-1 |
| V-velocity | v | m s-1 |
Height level parameters
Output of forecasts and analyses on pressure levels for defined time steps.
Height levels [m]:
15, 30, 50, 75, 100, 150, 200, 250, 300, 400, 500
Time steps:
Analysis:
● Store analysis output in six hourly intervals (at 00/06/12/18UTC) for the Unified Model and Harmonie
● Store analysis output in hourly intervals for COSMO
Forecasts for all models:
● T+1,2,3,4,5,6,9,12,15,18,21,24,27,30 started at 00 UTC and 12 UTC
● T+1,2,3,4,5,6 started at 06 UTC and 18 UTC
| Name | Abbreviation | Unit |
| Cloud cover | ccl | % |
| Pressure | pres | Pa |
| Specific cloud liquid water content | clwc | kg kg-1 |
| Specific cloud ice water content | ciwc | kg kg-1 |
| Relative humidity | r | % |
| Temperature | t | K |
| Wind speed | ws | m s-1 |
| Wind direction | wdir | degree true |
Surface level parameters
Time steps:
Analysis:
● Store analysis output in six hourly intervals (at 00/06/12/18UTC) for the Unified Model, Harmonie, MESCAN-SURFEX
● Store precipitation analysis (24 h accumulation from 06 UTC to 06 UTC of next day) output at 06TC for MESCAN-SURFEX
● Store hourly analysis output for COSMO, MESAN
Forecast:
● Store forecast output at T+1,2,3,4,5,6,9,12,15,18,21,24,27,30 started at 00 UTC and 12 UTC for the Unified Model, COSMO
● Store forecast output at T+1,2,3,4,5,6 started at 06 UTC and 18 UTC for the Unified Model, COSMO
● For Harmonie (started at 00/06/12/18UTC):
- Store sd, sr, al, rsn, slhf, sshf parameters (derived from ALADIN model driving SURFEX) at T+1,2,3,4,5,6 only
- Store all other parameters at T+1,2,3,4,5,6,9,12,15,18,21,24,27,30
● For MESCAN-SURFEX (started at 00/06/12/18UTC):
- Store parameters sp,tp,2r,2t,10si,10wdir, tidirswrf from forecast output at T+6 only (fields from ALADIN model driving SURFEX)
- Store all other parameters from forecast output at T+1,2,3,4,5,6
Static fields
Static fields are archived only as of the analysis type. For users' convenience, even they are invariant fields, they should be archived for all analysis output times. In case of ensemble products they should be archived with all ensemble members (again as of the analysis type only).
The surface roughness could be either static or changing parameter depending on model and should be handled accordingly as a static or a prognostic model field.
Soil level parameters
Time steps: the same as surface level parameters
Soil levels: parameters should be provided on original model levels or layers
- COSMO: 8 soil layers
level borders at 0, 0.01, 0.03, 0.09, 0.27, 0.81, 2.43, 7.29, 21.87 m - HARMONIE: 3 soil levels/layers (sot on levels, vsw on layers)
level depths are grid dependent - MESCAN-SURFEX: 14 soil layers (only 6 layers for preliminary shorter re-analysis runs)
level borders at 0, 0.01, 0.04, 0.1, 0.2, 0.4, 0.6 m - MO: 4 soil layers
level borders at 0, 0.1, 0.35, 1 and 3 m
Soil depth
The soil depth could be either a constant or a grid dependent parameter depending on given model soil scheme.
If constant, the soil depths should be mentioned only in documentation of given model.
If grid dependent it should be archived the same as other static fields for all analysis output times. In case of ensemble products it should be archived with all ensemble members (again as of the analysis type only).
Soil | Abbreviation | Unit |
|---|---|---|
| Liquid non-frozen volumetric soil water | liqvsm | m3 m-3 |
| sot | K | |
| Soil depth | sod | m |
| Volumetric field capacity | voltso | m3 m-3 |
| vsw | m3 m-3 | |
| Volumetric wilting point | vwiltm | m3 m-3 |
Additional information and links
- UERRA parameters
- UERRA parameters (life document on google drive)
- GRIB-API parameter database
- how is soil moisture defined for TIGGE
- example of soil layers in MARS
- description of multi-layer definition in MARS
- radiation in MARS
- latest WMO documentation on GRIB2 tables (normally it is under 1st link returned by google for "WMO latest")
Attached documents to this page which were used for creation of GRIB2 UERRA definitions (they are linked above too):
- radiation_in_mars.pdf (to understand the radiation fluxes)
- Parameter_table_20150427.docx (the latest official version of agreed upon UERRA parameters)