Outputs
Metview runs FLEXPART in a temporary directory. Having finished the simulation Metview converts and rename the output files and move them into the Output Path directory specified in the FLEXPART Run icon. The different output types are handled in a different way.
Gridded outputs
Gridded outputs are converted to GRIB using local GRIB definitions built into Metview.
FLEXPART GRIB files have their own local section (Section 2) containing additional information about the given field and the FLEXPART simulation itself. The snapshot below taken from Metview's Grib Examiner shows the currently defined set of keys in Section 2.
Handling FLEXPART GRIB output
To plot a particular parameter and level we need to filter the desired fields from the resulting FLEXPART output GRIB file. Unfortunately, Metview's Grib Filter icon cannot handle these files (partly due to the local GRIB definition they use) so we need to use Macro with some FLEXPART-related command to deal with this problems. See Using FLEXPART with Metview for details.
Concentration fields
Concentration fields are only produced for forward simulations when Output Field Type is set to conc or both in FLEXPART Run.
The output filename is:
conc_sSSS.grib
where SSS is the species index (starts from 1) with leading zeros. The actual field type and units are based on the Receptor Units settings in the FLEXPART Run icon.
Options in FLEXPART Run | Description | GRIB shortname | GRIB paramId | GRIB units |
|---|---|---|---|---|
| receptor_units=mass | mass concentration | conc | 20001 | kg m**-3 |
| receptor_units=mixr | mass mixing ratio | mxrm | 20002 | kg kg**-1 |
Volume mixing ratio fields
Volume mixing ratio fields are only produced for forward simulations when Output Field Type is set to mixr or both in FLEXPART Run.
The output filename is:
pptv_sSSS.grib
where SSS is the species index (starts from 1) with leading zeros.
| Description | GRIB shortname | GRIB paramId | GRIB units |
|---|---|---|---|
| volume mixing ratio | mxrv | 20052 | mol mol**-1 |
Dry and wet deposition fields
These fields are only produced for forward simulations when Output Field Type is set to conc, mixr or both in FLEXPART Run. They are always inserted into the concentration or/and volume mixing ratio files.
| Description | GRIB shortname | GRIB paramId | GRIB units |
|---|---|---|---|
| dry deposition | fdd | 20197 | kg m**-2 |
| wet deposition | fwd | 20198 | kg m**-2 |
Flux fields
These fields are only produced when Output Flux is set to on in FLEXPART Run. The output filename is:
flux_sSSS.grib
where SSS is the species index (starts from 1) with leading zeros.
| Description | GRIB shortname | GRIB paramId | GRIB units |
|---|---|---|---|
| eastward flux | feflux | 20199 | kg m**-2 s**-1 |
| westward flux | fwflux | 20200 | kg m**-2 s**-1 |
| southward flux | fnflux | 20201 | kg m**-2 s**-1 |
| northward flux | fsflux | 20202 | kg m**-2 s**-1 |
| upward flux | fuflux | 20203 | kg m**-2 s**-1 |
| downward flux | fdflux | 20204 | kg m**-2 s**-1 |
Residence time/response fields
These fields are only produced for backward simulations when Output Field Type is set to rtime in FLEXPART Run. The output filename is:
time_sSSS.grib
where SSS is the species index (starts from one) with leading zeros.
Plume trajectories
Trajectories are produced when Output Trajectory is set to on in FLEXPART Run. The ASCII file generated by FLEXPART is split according to releases and converted into another (CSV) format that is better suited to metview. The output filenames are:
tr_rRRR.csv
where R is the release number (starts from one) with leading zeros. The first row in the trajectory file contains metadata as a set of key value pairs, while the the second row contains the header. The table below gives a detailed description about the different columns.
| Column | Name (header) | Units | Description |
|---|---|---|---|
| 1 | time | s | the elapsed time in seconds since the middle point of the release interval |
| 2 | meanLon | degrees | mean longitude position for all the particles |
| 3 | meanLat | degrees | mean latitude position for all the particles |
| 4 | meanZ | m | mean height for all the particles (above sea level) |
| 5 | meanTopo | m | mean topography underlying all the particles |
| 6 | meanPBL | m | mean PBL (Planetary Boundary Layer) height for all the particles (above ground level) |
| 7 | meanTropo | m | mean tropopause height at the positions of particles (above sea level) |
| 8 | meanPv | PVU | mean potential vorticity for all the particles |
| 9 | rmsHBefore | km | total horizontal RMS (root mean square) distance before clustering |
| 10 | rmsHAfter | km | total horizontal RMS distance after clustering |
| 11 | rmsVBefore | m | total vertical RMS distance before clustering |
| 12 | rmsVAfter | m | total vertical RMS distance after clustering |
| 13 | pblFract | % | fraction of particles in the PBL |
| 14 | pv2Fract | % | fraction of particles with PV<2pvu |
| 15 | tropoFract | % | fraction of particles within the troposphere |
| 16* | clLon_N | degrees | mean longitude position for all the particles in cluster N |
| 17* | clLat_N | degrees | mean latitude position for all the particles in cluster N |
| 18* | clZ_N | m | mean height for all the particles in cluster N (above sea level) |
| 19* | clFract_N | % | fraction of particles in cluster N (above sea level) |
| 20* | clRms_N | km | total horizontal RMS distance in cluster N |
Columns 16-20 get repeated for each cluster.
Receptor output
Output at receptor points are produced when Receptors is set to on in FLEXPART Run. The binary file generated by FLEXPART is split according to species and converted to CSV.
When Receptor Units is set to mass in FLEXPART Run the output filename is:
receptor_conc_sSSS.csv
When Receptor Units is set to mixr in FLEXPART Run the output filename is
receptor_pptv_sSSS.csv
where SSS is the species number (with leading zeros).