Versions Compared

Old Version 2

changes.mady.by.user Sandor Kertesz

Saved on

compared with

New Version 3

changes.mady.by.user Sandor Kertesz

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.
Section
Column
width76px

Column

This icon generates the gridded input data and the AVAILABLE file needed to run the FLEXTRA trajectory model. The input forecast or analysis fields are automatically retrieved from ECMWF's MARS archive.

The macro language equivalent is flextra_prepare().

About FLEXTRA input  data

FLEXTRA requires input fields on a regular latitude-longitude grid in GRIB format. The input data must contain four three-dimensional fields: the two horizontal wind components, vertical velocity and temperature. Two additional two-dimensional fields are needed as well: topography and surface pressure. The three-dimensional input data has to be available on ECMWF model (i.e. η) levels defined by a hybrid vertical coordinate system. An important restriction is that all the data fields used within a FLEXTRA run must have the same domain size, resolution, number of levels, etc.

All the required fields, with one exception, can be retrieved from ECMWF's MARS archive. The only exception is vertical velocity because FLEXTRA needs the following field for its computations:

 

Mathinline
\dot \eta \frac{\partial \eta}{\partial p}
 

Since only

 

Mathinline
\dot \eta
 

is archived in MARS the full product needs to be computed during the data preparation process (FLEXTRA Prepare does it for you).

FLEXTRA requires all the input GRIB files to be in the same folder using the following file naming convention: ENyymmddhh. In addition to the GRIBs FLEXTRA needs several parameter files as well. Most of these files are automatically generated by Metview in the background, so users do not need to create them. The only exception is the file called AVAILABLE because it can be optionally provided by the user.

 

Info
All the date parameters used for FLEXTRA Prepare has yyyymmdd format. Relative dates are allowed to use: e.g. -1 means yesterday, 0 means today etc.                   

The

...

VAPOR Prepare Editor

...

VAPOR Input Mode

Specifies the data preparation mode. The possible values are: Icon and Path.

In Forecast mode the selected steps of a given forecast can be used for data generation. If the mode is set to Period a period with a start and end date and constant time-step can be defined. In this case FLEXTRA Prepare tries to retrieve analysis fields from MARS whenever it is possible (for dates in the past) and uses forecast fields otherwise (for dates in the future).

VAPOR Input Data

Specifies the data preparation mode. The possible values are: Forecast and Period.

In Forecast mode the selected steps of a given forecast can be used for data generation. If the mode is set to Period a period with a start and end date and constant time-step can be defined. In this case FLEXTRA Prepare tries to retrieve analysis fields from MARS whenever it is possible (for dates in the past) and uses forecast fields otherwise (for dates in the future).

VAPOR Surface Params

The list of the surface parameters from the input GRIB data to be converted into VAPOR format.  The default value is an empty string. 

VAPOR Upper Params

The list of the upper level parameters from the input GRIB data to be converted into VAPOR format. The default value is an empty string.

VAPOR Vertical Grid Type

The type of the vertical grid in VAPOR. The possible values are: Layered and Regular.

Vapor Elevation Param

The name of the upper level GRIB parameter interpreted as the elevation of the upper levels. Available when Vapor Vertical Grid Type is Layered.

Vapor Bottom Coordinate

The name of the upper level GRIB parameter interpreted as the elevation of the upper levels. Available when Vapor Vertical Grid Type is Layered.

Vapor Top Coordinate

The name of the upper level GRIB parameter interpreted as the elevation of the upper levels. Available when Vapor Vertical Grid Type is Layered.

Vapor Area Selection

The name of the upper level GRIB parameter interpreted as the elevation of the upper levels.

...

Available when Vapor Vertical Grid Type is Layered.

Vapor Area

Specifies the area of the output grid in south/west/north/east format. The default value is  -90/-180/90/180.

Vapor 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 degrees units). The default value is: 1/1.

Vapor Refinement Level

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 degrees units). The default value is: 1/1.

Vapor Vdf Name

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 degrees units)

Flextra Fc Mars Expver

The MARS experiment identifier of the forecast fields. The default value is: 1 (operational forecast). /1.

Vapor Output Path

Specifies the output directory (it has to be an absolute path) where the GRIB files and the AVAILABLE file will be generated. If this directory does not exist Metview will create it. The output GRIB files have the following naming convention: ENyymmddhh.

Vapor Reuse Input

If this parameter is set On FLEXTRA Prepare checks the existence of the data files to be generated and if they are already in place no new data is retrieved and processed. If it is Off all the fields are always retrieved and processed and the existing data files are overwritten. The same happens to the AVAILABLE file. The existence of a FLEXTRA input GRIB file is checked by using the file name and a set of GRIB API keys from the first message in the file. These keys are as follows: date, time, stepRange, gridType, iDirectionIncrement, jDirectionIncrement, latitudeOfFirstGridPoint, latitudeOfLastGridPoint, longitudeOfFirstGridPoint, longitudeOfLastGridPoint.





Flextra An Mars Expver

The MARS experiment identifier of the analysis fields. The default value is 1 (operational analysis). 

...

Specifies the output directory (it has to be an absolute path) where the GRIB files and the AVAILABLE file will be generated. If this directory does not exist Metview will create it. The output GRIB files have the following naming convention: ENyymmddhh.

Vapor Bottom Coordinate

The name of the upper level GRIB parameter interpreted as the elevation of the upper levels. Available when Vapor Vertical Grid Type is Layered.