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This icon runs the FLEXTRA trajectory model.

From Macro/Python the icon can be called as flextra_run().

Visit the FLEXTRA interface page to find out details about how FLEXTRA is used in Metview. A FLEXTRA-related tutorial can be found here.

The FLEXTRA Run Editor

Flextra Exe Path

Specifies a user defined FLEXTRA executable. Both absolute and relative path can be given here. If it is left blank (this is the default) Metview will use the MV_FLEXTRA_EXE environment variable to locate the executable.

Flextra Input Mode

Specifies how the input data path is specified. The possible values are path and icon. When it is set to path we will specify the input data files and the AVAILABLE file by their paths. While in icon mode the input data is specified by a FLEXTRA Prepare icon in Flextra Input Data. The default value is path.

Flextra Input Data

Specifies the location of the input data files using a FLEXTRA Prepare icon.

Flextra Run Label

Specifies the FLEXTRA run label. The default value is: "FLEXTRA RUN".

Flextra Input Path

Specifies the location of the input data files. Both an absolute and relative path can be given here. Enabled when Flextra Input Mode is path.

Flextra Available File Path

Specifies the location of the AVAILABLE file. The default is SAME_AS_INPUT_PATH, which means that the AVAILABLE file is located in the same directory as the input data. Enabled when Flextra Input Mode is path.

Flextra Run Mode

Specifies the run mode for the FLEXTRA simulation.  The possible values are as follows:

  • In normal mode, a group of trajectories is specified starting from the same point but at different times. Several starting points (thus several groups of trajectories) can be defined for a single FLEXTRA run.
  • In cet mode, trajectories are generated starting from the points of a user-defined uniform grid in a three-dimensional domain.
  • In flight mode, both the starting location and starting time for each trajectory can be set individually. This mode is useful to calculate e.g. trajectories released along the flight track of an aircraft.

The default value is normal.

Flextra Trajectory Direction

Specifies the FLEXTRA simulation direction in time. The possible values are: forward and backward. The default value is forward.

Flextra Trajectory Length

Specifies the length of the FLEXTRA simulation. The format is HHH[:MM[:SS]. The default value is: 48 (i.e. 48 hours).

Flextra First Starting Date

Specifies the start date of the period within which the trajectories will be released. Enabled when Flextra Run Mode is set to normal or cet. The format is YYYYMMDD Relative dates are allowed: e.g. -1 means yesterday, 0 means today, etc. 

Flextra First Starting Time

Specifies the start time of the period within which the trajectories will be released. Enabled when Flextra Run Mode is set to normal or cet. The format is HH[:MM[:SS].

Flextra Last Starting Date

Specifies the end date of the period within which the trajectories will be released. Enabled when Flextra Run Mode is set to normal or cet. The format is YYYYMMDD Relative dates are allowed: e.g. -1 means yesterday, 0 means today, etc.

Flextra Last Starting Time

Specifies the end time of the period within which the trajectories will be released. Enabled when Flextra Run Mode is set to normal or cet.  The format is HH[:MM[:SS].

Flextra Starting Time Interval

Specifies the starting interval of trajectories within the starting period. Enabled when Flextra Run Mode is set to normal or cet. The format is HHH[:MM[:SS]. The default value is: 6 (i.e. 6 hours).

Flextra Output Interval Mode

Specifies how the output data (i.e. trajectory waypoints) will be written out into the output file. It can have three values:

  • original: The trajectory points are written out into the output file exactly at the computational time steps. In the FLEXTRA terminology these are called flexible time steps.
  • interval: The trajectory points are written out into the output file at regular intervals specified by parameter Flextra Output Interval Value. In the FLEXTRA terminology these are called constant time steps.
  • both: Two output files will be generated: one for the flexible time steps and one for the constant time steps.

The default value is interval.

Flextra Output Interval Value

Specifies the output frequency when Flextra Output Interval Mode is set to interval or both. The format is HHH[:MM[:SS]. The default value is 3, which means 3 hourly output.

Flextra Normal Types

Specifies the list of trajectory types as numerical IDs when Flextra Run Mode is set to normal. The possible values are as follows:

Numerical IDDescription
13 dimensional
2model level
3mixing layer
4isobaric
5isentropic

The default value is 1 (three-dimensional trajectories).

Flextra Normal Names

Specifies the trajectory names when Flextra Run Mode is set to normal.

Flextra Normal Latitudes

Specifies the latitudes of the trajectory start points when Flextra Run Mode is set to normal.

Flextra Normal Longitudes

Specifies the longitudes of the trajectory start points when Flextra Run Mode is set to normal.

Flextra Normal Levels

Specifies the levels of the trajectory start points when Flextra Run Mode is set to normal.

Flextra Normal Level Units

Specifies the level types (as numerical IDs) of the trajectory start points when Flextra Run Mode is set to normal. The possible values are as follows:

Numerical IDDescription
1Metres above sea level
2Metres above ground level
3hPa

The default value is 1 (metres above sea level).

Flextra Cet Types

Specifies the list of trajectory type as numerical IDs or strings when Flextra Run Mode is set to cet. The possible values are as follows:

Numerical IDString (case insensitive)
13d
2model level
4isobaric
5isentropic

The default value is 1 (three-dimensional trajectories).

Flextra Cet Name

Specifies the trajectory name when Flextra Run Mode is set to cet.

Flextra Cet Area

Specify the geographical area of the start grid by a S/W/N/E list.

Flextra Cet Dx

Specifies the start grid resolution in West-East direction in degrees when Flextra Run Mode is set to cet. The default value is 1.

Flextra Cet  Dy

Specifies the start grid resolution in South-North direction in degrees when Flextra Run Mode is set to cet. The default value is 1.

Flextra Cet Top Level

Specifies the top level of the start grid volume when Flextra Run Mode is set to cet. The default value is 1.

Flextra Cet Bottom Level

Specifies the bottom level of the start grid when Flextra Run Mode is set to cet. The default value is 1.

Flextra Cet  Dz

Specifies the start grid vertical resolution when Flextra Run Mode is set to cet. The default value is 1

Flextra Cet Level Units

Specifies the level types (as numerical IDs or strings) of the start grid when Flextra Run Mode is set to cet. The possible values are as follows:

Numerical IDString (case insensitive)Description
1metres aslMetres above sea level
2metres aglMetres above ground level
3hPa

The default value is 1 (metres above sea level).

Flextra Flight Types

Specifies the list of trajectory types as numerical IDs or strings when Flextra Run Mode is set to flight. The possible values are as follows:

Numerical IDString (case insensitive)
13d
2model level
4isobaric
5isentropic

The default value is 1 (three-dimensional trajectories).

Flextra Flight Name

Specifies the trajectory name when Flextra Run Mode is set to flight.

Flextra Flight Latitudes

Specifies the latitudes of the trajectory start points when Flextra Run Mode is set to flight.

Flextra Flight Longitudes

Specifies the longitudes of the trajectory start points when Flextra Run Mode is set to flight.

Flextra Flight Levels

Specifies the levels of the trajectory start points when Flextra Run Mode is set to flight.

Flextra Flight Level Units

Specifies the level types (as numerical IDs or strings) of the trajectory start points when Flextra Run Mode is set to flight. The possible values are as follows

Numerical IDString (case insensitive)Description
1metres aslMetres above sea level
2metres aglMetres above ground level
3hPa

The default value is 1 (metres above sea level).

Flextra Flight Starting Dates

Specifies the starting dates of the trajectories when Flextra Run Mode is set to flight. The format is YYYYMMDD. Relative dates are allowed: e.g. -1 means yesterday, 0 means today, etc. 

Flextra Flight Starting Times

Specifies the starting times of the trajectories when Flextra Run Mode is set to flight. The format is HH[:MM[:SS].

Flextra Interpolation Type

Specifies the interpolation type. The possible values are as follows:

ValueDescription
1
  • horizontal interpolation bicubic
  • vertical interpolation polynomial
  • temporal interpolation linear
>1
  • horizontal interpolation bilinear         
  • vertical interpolation linear
  • temporal interpolation linear

The default value is 1.

Flextra Cfl Spatial

Specifies the factor by which the time step must be smaller than that determined from the CFL criterion.  This factor must be >1! The default value is.  2.0.

Flextra Cfl Temporal

Specifies the factor by which the time step must be smaller than the time interval of the wind fields. This factor must be >1! The default value is 2.0.