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This icon runs the FLEXTRA trajectory model.
The macro language equivalent is flextra_run(). From Macro/Python the icon can be called as flextra_run(). |
A tutorial about using FLEXTRA in Metview can be found here. |
What is FLEXTRA?FLEXTRA is an atmospheric trajectory model used by a wide scientific community. It can be driven by meteorological input data from a variety of global and regional models including ECMWF analyses and forecasts. FLEXTRA can compute both forward and backward trajectories using various trajectory types such as: three-dimensional, model level, mixing layer, isobaric and isentropic trajectories. Trajectory computations can be carried out in the three different modes. These 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.
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The FLEXTRA Run Editor
Output Path
Specifies the location of the output data files. Both an absolute and relative path can be given here. Please note that Metview converts FLEXTRA output into other formats and only these converted results are copied from the work directory into Output Path. For further details about the output formats click here.
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 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 Input Data 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 using. The default is SAME_AS_INPUT_PATH, which mean 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 filight 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.
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.
Flextra First Starting Date
Specifies the start date of the period whiten which the trajectories will be released.
Flextra First Starting Time
Specifies the start time of the period whiten which the trajectories will be released.
Flextra Last Starting Date
Specifies the end date of the period whiten which the trajectories will be released.
Flextra Last Starting Time
Specifies the end time of the period whiten which the trajectories will be released.
Flextra Starting Time Interval
Specifies the starting interval of trajectories within the starting period.
Flextra Output Interval Mode
Specifies how the output data (i.e. trajectory waypoints) will be written out.
Flextra Output Interval Value
Specifies the value used to write the output data (i.e. trajectory waypoints) out.
Flextra Normal Types | 1 |
Flextra Normal Names | Katla |
Flextra Normal Latitudes | 63.63 |
Flextra Normal Longitudes | -19.05 |
Flextra Normal Levels | 1512 |
Flextra Normal Level Units | 1 |
User 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.
User Resources Path
Specifies the location of the user defined parameter files (IGBP_int1.dat, OH_7lev_agl.dat, surfdata.t, surfdepo.t ) needed to run FLEXTRA. Both an absolute and relative path can be given here. If it is left blank (this is the default) Metview will use the MV_FLEXTRA_RESOURCES environment variable to locate the resources. For further details about the resources click here.
Simulation Direction
Specifies the FLEXTRA simulation direction in time. The possible values are: Forward and Backward. The default value is Forward.
Starting Date
Specifies the beginning date of the simulation in YYYYMMDD format. Relative dates are allowed: e.g. -1 means yesterday, 0 means today, etc.
Starting Time
Specifies the beginning time of the simulation in HH[:MM[:SS]] format.
Ending Date
Specifies the ending date of the simulation in YYYYMMDD format. Relative dates are allowed: e.g. -1 means yesterday, 0 means today, etc.
Ending Time
Specifies the ending time of the simulation in HH[:MM[:SS]] format.
Output Rate
Specifies the frequency for the output generation. The output is averaged over the period given in Output Averaging Interval. The format is HHHH[:MM[:SS]]. The default value is 3 (hours).
Output Averaging Interval
Specifies the averaging interval for the output generation in HHHH[:MM[:SS]] format. If 0 is given here instantaneous values are written into the output files. The default value is 3 (hours).
Output Sampling Rate
Specifies the sampling rate used for the averaging of the output. This period must be shorter than the Output Averaging Interval. The format is HHHH[:MM[:SS]]. The default value is 1 (hour).
Output Field Type
Specifies the type of the gridded output fields. The possible values are:
for forward simulations:
- none (no gridded output)
- conc (concentration)
- mixr (mass mixing ratio)
- both (concentration and mass mixing ratio)
for backward simulations:
- none (no gridded output)
- rtime (residence time/response function)
The default value is conc. For more details about gridded output click here.
Output Flux
Specifies if the fluxes should be computed and written out as a gridded output (on or off). Fluxes corresponding to northward, southward, eastward, westward, upward and downward directions are calculated for each grid cell of the output grid.The control surfaces are placed in the middle of each output grid cell. The default value is off. For more details about flux output click here.
Output Trajectory
Specifies if the plume trajectories should be computed (on or off). The default value is off. For more details about trajectory output click here.
Output Area
Specifies the area for the gridded output in degrees in S/W/N/E format. The default value is -90/-180/90/180.
Output Grid
Specifies the grid resolution for the gridded output in degrees as east_west_resolution/north_south_resolution. The default value is 1/1.
Output Levels
Specifies the list of height levels of the gridded output. The levels are given in metres units. The default value is an empty list.
User Species Path
Specifies the location of the user defined species files. Both an absolute and relative path can be given here. If it is left blank (this is the default value) Metview will use the MV_FLEXTRA_SPECIES environment variable to locate the species. For more details about the species click here.
Release Species
Specifies the list of the species released for the simulation. At all the release locations the same species are emitted. The species are identified by the NNN number (with leading zeros) appearing in the the name of the SPECIES_NNN files. These files contain the physical and chemical properties of species. For more details about the species click here.
Release Units
Specifies the units of the mass of the released species. The possible options are mass and mixr. The default value is mass. See the table below to find out what the actual units mean.
for forward simulations:
| Release Units | Receptor Units |
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| keyword | units | keyword | units in concentration fields |
|---|
| mass | kg | mass | kg m**-3 |
| mass | kg | mixr | kg kg**-1 |
| mixr | 1 | mass | kg m**-3 |
| mixr | 1 | mixr | kg kg**-1 |
for backward simulations:
| Release Units | Receptor Units |
|---|
| keyword | units | keyword | units in residence time fields |
|---|
| mass | 1 | mass | s |
| mass | 1 | mixr | s m**3 kg**-1 |
| mixr | 1 | mass | s kg m**-3 |
| mixr | 1 | mixr | s |
Releases
Specifies the releases as a group of FLEXTRA Release icons.
Receptor units
Specifies the concentration units at the receptor. The possible options are mass (mass concentrations) and mixr (mass mixing ratio). The default value is mass. See the table above to find out what the actual units mean.
Receptors
Enables the usage of receptor sites (on or off). When it is enabled the list of receptor sites can be defined via Receptor Names, Receptor Latitudes and Receptor Longitude. The default value is off. For more details about receptor output click here.
Receptor Names
Specifies the list of receptor site names.The default value is an empty list.
Receptor Latitudes
Specifies the list of receptor site latitudes. The default value is an empty list.
Receptors Longitudes
Specifies the list of receptor site longitudes. The default value is an empty list.
Age Classes
Specifies the list of times for the age class calculation. If it is left blank (this is the default value) no age class is defined.
Particle Splitting
Specifies the interval for particle splitting in HHHH[:MM[:SS]] format. Each particle is split into two after travelling the multiple of this interval. If 0 (default value) is given here particle splitting is disabled.
Sync Interval
All processes are synchronized with this time interval, therefore, all other time constants must be multiples of this value. Output interval and Output Averaging Interval must be at least twice of this value. The default value is 900.
Ctl
Specifies the factor by which the time step must be smaller than the Lagrangian time scale (TL). CTL must be >1 for time steps shorter than the Lagrangian time scale. If CTL<0, a purely random walk simulation is done. The default value -4.
Vertical Timestep Reduction
Specifies the reduction factor (as an integer) for the time step used for vertical wind. The default value is 4.
Subgrid Terrain
Enables subgridscale terrain parametrization (increase of mixing heights due to subgridscale orographic variations) (on or off). The default value is off.
Convection
Enables convection parametrization (on or off). The default value is off.
Output For Each Release
Specifies whether a separate output fields should be generated for each release (on or off). When this option is set to off for forward simulations the output fields for a given species contain the sum of all the releases. For backward simulations it must be set to on. The default value is off.
Quasi Lagrangian
Specifies whether particles should be numbered individually (on) or identified by the release location number (off). The default value is off.
Domain Fill
Enables the domain fill mode. The possible values are as follows:
- none: domain fill is disabled
- full: in this mode the the particles are not released at specific locations but the 3D-volume of the first release is taken and the particles are uniformly distributed in the volume proportionally to air density. Each particle will receive the same mass, altogether accounting for the total atmospheric mass. Subsequently, particles can move freely in the atmosphere.
- o3_tracer: in this mode domain-filling is to simulate a stratospheric ozone tracer. This option is similar to fill option, but only particles in the stratosphere (defined by PV < 2 pvu) are released.
The default value is none.
Sensitivity
Enables computing sensitivity to initial conditions in backward simulations. The possible values are none, mass (mass concentration units) or mixr (mass mixing ratio units). The default value is none.
The ODB Filter Editor
ODB Filename
Specifies the path to the input ODB
ODB Data
Specifies the input ODB as an icon. If both an icon (in ODB Data) and a filename (in ODB Filename) are specified the icon takes precedence.
ODB Query
Specifies the ODB/SQL query to run.
ODB NB Rows
Specifies the maximum number of rows in the result. If -1 is given here the number of rows is not limited in the output. The default value is -1.
Fail On Empty Output
When it is set to Yes the icon will not fail if the resulting ODB is empty (in Macro the return value is nil while in Python it is None). Otherwise when it is set to No the icon will fail on empty output. The default value is Yes.