This icon retrieves and post-processes GRIB data from ECMWF's MARS archive so that it could be used in the Met.3D visualisation system. The resulting data is a GRIB file.
The macro language equivalent is met3d_prepare().
The Met3D Prepare Editor
Mode
Specifies the main retrieval mode. The possible values are: forecast and analysis.
In forecast mode the selected steps of a given forecast can be used for data generation. If the mode is set to analysis a period with a start and end date and constant time-step can be defined.
Product
Specifies the type of data to be retrieved from MARS. The possible values are: hires and ens. The default is hires.
In hires mode the operational deterministic forecast is retrieved. While in ens mode the operational ENS forecast (both "pf" and "cf" members) is used. If Mode is set to analysis this option is disabled and automatically set to hires.
Number
Specifies the perturbed ensemble members to be retrieved as a list. The default value is: 1/TO/50. Only enabled when Product is set to ens.
Levtype
Specifies the type of vertical levels. The possible values are: pl (pressure levels) and ml (model levels). The default value is: pl.
Pl_Levelist
Specifies the list of pressure levels in hPa when Levtype is pl. The default value is: 1000/925/850/700/500/400/300.
Ml_Levelist
Specifies the list of model levels when Levtype is ml. The default value is: -10
If the list of model levels is a sole negative number (-N) it means that all the model levels will be retrieved from the surface up to level N. Please note that model level numbering starts at the topmost atmospheric level (see here for level information)
Params_2D
Specifies the list of surface parameters The default value is: 2t/10u/10v.
Please note that when the following precipitation rate parameters are specified:
- Convective rain rate: crr
- Large scale rain rate: lsrr
- Convective snowfall rate water equivalent: csfr
- Large scale snowfall rate water equivalent: lssfr
their sum is computed and added as a tprate field to the results.
Params_3D
Specifies the list of upper level parameters The default value is: t/q/u/v
Please note that on model levels z (geopotential) is not archived in MARS. However, when z is specified in Param_3D it will be automatically computed (the fields needed for the computations will also be automatically retrieved). To be able to plot "jet cores" in 3D z is needed.
Date
Specifies the run date of the forecast. Available when Mode is forecast. The default value is -1 (i.e. yesterday).
Time
Specifies the run time of the forecast in hours. Available when Mode is forecast. The default value is 0.
Step
Specifies the forecast steps in hours. Here a list of values can be given. Available when Mode is forecast. The default value is 0.
Analysis Start Date
Specifies the start date of the analysis period. Available when Mode is analysis. The default value is -1 (i.e. yesterday).
Analysis Start Time
Specifies the start time of the period. Available when Mode is analysis. The default value is 0.
Analysis End Date
Specifies the end date of the period. Available when Mode is analysis. The default value is -1 (i.e. yesterday).
Analysis End Time
Specifies the end time of the period. Available when Mode is analysis. The default value is 0.
Analysis Step
Specifies the time step of the analysis period in hours. The allowed values are as follows: 6 or 12. Available when Mode is analysis. The default value is 6.
Area
Specifies the area of the output grid in south/west/north/east format. The default value is -90/-180/90/180.
Grid
Specifies the resolution of the output grid in dx/dy format, where dx is the grid increment in east-west direction, while dy is the grid increment in north-south direction (both in units of degrees). The default value is: 1/1.
Retrieve Group By Time
Specifies how the MARS retrievals should be executed. When it is set to ON the following happens:
- forecasts: all steps are retrieved together
- analyses: times within the same day are retrieved together
When it is set to OFF each step/time is retrieved separately (in a loop). The default value is ON.