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Input data may be specified either by giving a path in the Source parameter or by giving a GRIB-based data object in the Data parameter. Note that you should specify either Source or Data, not both.
Specifies the GRIB file path.
Drop a MARS Retrieval or a GRIB file icon inside this icon field. In Python or Macro, supply a Fieldset object.
Select a method for specifying the output grid.
If Grid Definition Mode is set to Template, supply the path to a template GRIB file; the output GRIB will use the same grid as the template.
If Grid Definition Mode is set to Template, supply a GRIB-based data object in the Data parameter; the output GRIB will use the same grid as the template.
Supply a grid definition as described here: grid - keyword in MARS/Dissemination request.
Examples of valid grid definitions:
GUI | Python / Macro | Result |
---|---|---|
1/1 | [1, 1] | A regular lat/lon grid with 1x1 degree point spacing |
0.25/0.25 | [0.25, 0.25] | A regular lat/lon grid with 0.25x0.25 degree point spacing |
O1280 | "O1280" | An octahedral reduced Gaussian grid, octahedral with 1280 latitude lines between the pole and equator |
N640 | "N640" | An 'original' reduced Gaussian grid, with 640 latitude lines between the pole and equator |
F400 | "F400" | A regular Gaussian grid, with 400 latitude lines between the pole and equator |
Specifies the geographical area that the output fields will cover, the default being for the whole globe. Enter lat/lon bounds of an area separated by a "/" (North/West/South/East), or in Macro or Python provide a list, e.g. [south, west, north, east]; alternatively, use the assist button to define the area graphically.
For example, this set of parameters generates the following output data:
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Needs to be checked!
Rotation is specified by selecting a new coordinate for the South pole. In Python or Macro, enter [lat, lon]
; in the GUI, enter lat/lon
or use the coordinate assist button to graphically select the point.
These parameters are available if Grid Definition Mode is set to Lambert Conformal or Lambert Azimuthal Equal Area. The names follow the naming convention in the descriptions of these projections here:
Most of these parameters are required and do not have default values, meaning that they must be filled in.
The parameters are: First Point, Dx In Metres, Dy In Metres, Lad In Degrees, Lov In Degrees, Standard Parallel In Degrees, Central Longitude In Degrees, Latin 1 In Degrees, Latin 2 In Degrees, Nx, Ny.
If the input files are spectral, the following parameters are used to fine-tune the conversion to grid points.
Describes how to treat the incoming spherical harmonics before the transformation to grid points. For more details, see truncation - keyword in MARS/Dissemination request. Possible values are Automatic, None or a number describing the spectral truncation to be applied.
Describes the intermediate grid to which the transform is performed. For more details, see intgrid - keyword in MARS/Dissemination request. Possible values are Automatic , None , Source or the name of the desired intermediate grid.
Specifies the width of a frame within a given sub-area. The width of the frame is specified as an integer number of grid points inwards from a given area. See also frame - keyword in MARS/Dissemination request.
The following plots show a sub-area with Frame=10.
Activates processing that is particular to wind fields. Possible options are:
By default, this module will assume there are no wind fields in the input, and it will not automatically scan for pairs of U/V fields - it is up to the user to know that their input consists of wind fields and to use this setting in order to perform the correct processing.
Activates a nabla (differential) operator processing on the fields. Possible functions are:
QQQ. Possible values are On and Off.
Specifies the type of interpolation to be used on the fields. The default is Automatic, which selects either Linear or Nearest Neighbour based on an internal table of known parameters. If the parameter is unknown, the default will be Linear. The possible interpolation methods are:
Available for any of the 'nearest' interpolation methods. Possible values are:
Only available if Interpolation is K Nearest Neighbours. QQQ (description)
Possible values are:
Only available if Interpolation is K Nearest Neighbours and Distance Weighting is one of the 'NClosest' methods. This parameter specifies the number of closest points to be considered. Default=4.
Only available if Interpolation is K Nearest Neighbours. QQQ
Only available if Interpolation is K Nearest Neighbours. QQQ
Only available if Interpolation is K Nearest Neighbours. QQQ
Only available if Interpolation is K Nearest Neighbours. QQQ
Only available if Interpolation is Conservative Finite Element. QQQ
Only available if Interpolation is Conservative Finite Element. QQQ
QQQ. Possible values are:
Only available if Non Linear is Simulated Missing Value. QQQ (description)
Only available if Non Linear is Simulated Missing Value. QQQ (description)
Only available if Interpolation is Nearest LSM. Possible values are On and Off.
Only available if Distance Weighting With Lsm is not Off. QQQ.
QQQ.
Specifies whether the input LSM file will come from LSM Named Input (Named) or LSM File Input (File).
Provide one a of a set of predefined names of LSM inputs from the following list:
Provide the path to an LSM GRIB file.
QQQ.
QQQ
Specifies whether the input LSM file will come from LSM Named Output (Named) or LSM File Output (File).
Provide one a of a set of predefined names of LSM outputs from the following list:
Provide the path to an LSM GRIB file.
QQQ.
Provide the desired number of bits per value for the output fields. If left empty, this will take the value from the input fields. This option can also be used to simply change the number of bits per value in a Fieldset if no other processing options are given. Note that if Packing is set to ieee, then the only valid values for this parameter are 32 and 64.
Specifies the GRIB packing method for the output values. Possible values are:
Specifies the edition of GRIB format for the output files. Possible values are: