Output Data¶
The output data of flex_extract
are separated mainly into temporary files and the final FLEXPART
input files:
FLEXPART input files |
Temporary files (saved in debug mode) |
|
|
FLEXPART
input files¶
The final output files of flex_extract
are also the meteorological FLEXPART
input files.
The naming of these files depend on the kind of data extracted by flex_extract
.
Standard output files¶
In general, there is a file for each time step with the filename format:
<prefix>YYMMDDHH
The prefix
is by default defined as EN
and can be re-defined in the CONTROL
file.
Each file contains all meteorological fields needed by FLEXPART
for all selected model levels for a specific time step.
Here is an example output which lists the meteorological fields in a single file called CE00010800
where we extracted only the lowest model level for demonstration reasons:
$ grib_ls CE00010800
edition centre date dataType gridType stepRange typeOfLevel level shortName packingType
2 ecmf 20000108 an regular_ll 0 hybrid 91 u grid_simple
2 ecmf 20000108 an regular_ll 0 hybrid 91 v grid_simple
2 ecmf 20000108 an regular_ll 0 hybrid 91 etadot grid_simple
2 ecmf 20000108 an regular_ll 0 hybrid 91 t grid_simple
2 ecmf 20000108 an regular_ll 0 surface 1 sp grid_simple
2 ecmf 20000108 an regular_ll 0 hybrid 91 q grid_simple
2 ecmf 20000108 an regular_ll 0 hybrid 91 qc grid_simple
1 ecmf 20000108 fc regular_ll 0 surface 0 sshf grid_simple
1 ecmf 20000108 fc regular_ll 0 surface 0 ewss grid_simple
1 ecmf 20000108 fc regular_ll 0 surface 0 nsss grid_simple
1 ecmf 20000108 fc regular_ll 0 surface 0 ssr grid_simple
1 ecmf 20000108 fc regular_ll 0 surface 0 lsp grid_simple
1 ecmf 20000108 fc regular_ll 0 surface 0 cp grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 sd grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 msl grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 tcc grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 10u grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 10v grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 2t grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 2d grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 z grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 lsm grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 cvl grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 cvh grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 lcc grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 mcc grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 hcc grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 skt grid_simple
1 ecmf 20000108 an regular_ll 0 depthBelowLandLayer 0 stl1 grid_simple
1 ecmf 20000108 an regular_ll 0 depthBelowLandLayer 0 swvl1 grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 sr grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 sdor grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 cvl grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 cvh grid_simple
1 ecmf 20000108 an regular_ll 0 surface 0 fsr grid_simple
35 of 35 messages in CE00010800
Output files for pure forecast¶
Flex_extract
can retrieve forecasts which can be longer than 23 hours. To avoid collisions of time steps for forecasts of more than one day a new scheme for filenames in pure forecast mode is introduced:
<prefix>YYMMDD.HH.<FORECAST_STEP>
The <prefix>
is, as in the standard output, by default EN
and can be re-defined in the CONTROL
file. YYMMDD
is the date format and HH
the forecast time which is the starting time for the forecasts. The FORECAST_STEP
is a 3 digit number which represents the forecast step in hours.
Output files for ensemble predictions¶
Ensembles can be retrieved and are addressed by the grib message parameter number
. The ensembles are saved per file and standard filenames are supplemented by the letter N
and the ensemble member number in a 3 digit format.
<prefix>YYMMDDHH.N<ENSEMBLE_MEMBER>
Additional fields with new precipitation disaggregation¶
The new disaggregation method for precipitation fields produces two additional precipitation fields for each time step and precipitation type. They serve as sub-grid points in the original time interval. For details of the method see Disaggregation of Flux Data ??????????????????.
The two additional fields are marked with the step
parameter in the Grib messages and are set to “1” and “2” for sub-grid point 1 and 2 respectively.
The output filenames do not change in this case.
Below is an example list of precipitation fields in an output file generated with the new disaggregation method:
$ grib_ls
edition centre date dataType gridType stepRange typeOfLevel level shortName packingType
1 ecmf 20000108 fc regular_ll 0 surface 0 lsp grid_simple
1 ecmf 20000108 fc regular_ll 1 surface 0 lsp grid_simple
1 ecmf 20000108 fc regular_ll 2 surface 0 lsp grid_simple
1 ecmf 20000108 fc regular_ll 0 surface 0 cp grid_simple
1 ecmf 20000108 fc regular_ll 1 surface 0 cp grid_simple
1 ecmf 20000108 fc regular_ll 2 surface 0 cp grid_simple
Temporary files¶
Flex_extract
works with a number of temporary data files which are usually deleted after a successful data extraction. They are only stored if the DEBUG
mode is switched on (see The CONTROL parameters.
MARS grib files¶
Flex_extract
retrieves all meteorological fields from MARS and stores them in files ending with .grb
.
Since the request times and data transfer of MARS access are limited and ECMWF asks for efficiency in requesting data from MARS, flex_extract
splits the overall data request in several smaller requests. Each request is stored in an extra .grb
file and the file names are put together by several pieces of information:
<field_type><grid_type><temporal_property><level_type>.<date>.<ppid>.<pid>.grb
Description:
- Field type:
AN
- Analysis,FC
- Forecast,4V
- 4d variational analysis,CV
- Validation forecast,CF
- Control forecast,PF
- Perturbed forecast- Grid type:
SH
- Spherical Harmonics,GG
- Gaussian Grid,OG
- Output Grid (typically lat/lon),_OROLSM
- Orography parameter- Temporal property:
__
- instantaneous fields,_acc
- accumulated fields- Level type:
ML
- Model Level,SL
- Surface Level- ppid:
- The process number of the parent process of submitted script.
- pid:
- The process number of the submitted script.
The process ids should avoid mixing of fields if several flex_extract
jobs are performed in parallel (which is, however, not recommended). The date format is YYYYMMDDHH.
Example .grb
files for a day of CERA-20C data:
ANOG__ML.20000908.71851.71852.grb FCOG_acc_SL.20000907.71851.71852.grb ANOG__SL.20000908.71851.71852.grb OG_OROLSM__SL.20000908.71851.71852.grb ANSH__SL.20000908.71851.71852.grb
MARS request file¶
This file is a csv
file called mars_requests.csv
with a list of the actual settings of MARS request parameters (one request per line) in a flex_extract job. It is used for documenting the data which were retrieved and for testing reasons.
Each request consist of the following parameters, whose meaning mainly can be taken from The CONTROL parameters or The executable Script - run.sh: request_number, accuracy, area, dataset, date, expver, gaussian, grid, levelist, levtype, marsclass, number, param, repres, resol, step, stream, target, time, type
Example output of a one day retrieval of CERA-20c data:
request_number, accuracy, area, dataset, date, expver, gaussian, grid, levelist, levtype, marsclass, number, param, repres, resol, step, stream, target, time, type
1, 24, 40.0/-5.0/30.0/5.0, None, 20000107/to/20000109, 1, , 1.0/1.0, 1, SFC, EP, 000, 142.128/143.128/146.128/180.128/181.128/176.128, , 159, 3/to/24/by/3, ENDA, /mnt/nas/Anne/Interpolation/flexextract/flex_extract_v7.1/run/./workspace/CERA_testgrid_local_cds/FCOG_acc_SL.20000107.23903.23904.grb, 18, FC
1, 24, 40.0/-5.0/30.0/5.0, None, 20000108/to/20000108, 1, , 1.0/1.0, 85/to/91, ML, EP, 000, 130.128/133.128/131.128/132.128/077.128/246.128/247.128, , 159, 00, ENDA, /mnt/nas/Anne/Interpolation/flexextract/flex_extract_v7.1/run/./workspace/CERA_testgrid_local_cds/ANOG__ML.20000108.23903.23904.grb, 00/03/06/09/12/15/18/21, AN
2, 24, 40.0/-5.0/30.0/5.0, None, 20000108/to/20000108, 1, , OFF, 1, ML, EP, 000, 152.128, , 159, 00, ENDA, /mnt/nas/Anne/Interpolation/flexextract/flex_extract_v7.1/run/./workspace/CERA_testgrid_local_cds/ANSH__SL.20000108.23903.23904.grb, 00/03/06/09/12/15/18/21, AN
3, 24, 40.0/-5.0/30.0/5.0, None, 20000108, 1, , 1.0/1.0, 1, SFC, EP, 000, 160.128/027.128/028.128/244.128, , 159, 000, ENDA, /mnt/nas/Anne/Interpolation/flexextract/flex_extract_v7.1/run/./workspace/CERA_testgrid_local_cds/OG_OROLSM__SL.20000108.23903.23904.grb, 00, AN
4, 24, 40.0/-5.0/30.0/5.0, None, 20000108/to/20000108, 1, , 1.0/1.0, 1, SFC, EP, 000, 141.128/151.128/164.128/165.128/166.128/167.128/168.128/129.128/172.128/027.128/028.128/186.128/187.128/188.128/235.128/139.128/039.128/173.128, , 159, 00, ENDA, /mnt/nas/Anne/Interpolation/flexextract/flex_extract_v7.1/run/./workspace/CERA_testgrid_local_cds/ANOG__SL.20000108.23903.23904.grb, 00/03/06/09/12/15/18/21, AN
VERTICAL.EC¶
The vertical discretization of model levels. This file contains the A
and B
parameters to calculate the model level height in meters.
Index file¶
This file is usually called date_time_stepRange.idx
. It contains indices pointing to specific grib messages from one or more grib files. The messages are selected with a composition of grib message keywords.
flux files¶
The flux files contain the de-accumulated and dis-aggregated flux fields of large scale and convective precipitation, eastward turbulent surface stress, northward turbulent surface stress, surface sensible heat flux and the surface net solar radiation.
flux<date>[.N<xxx>][.<xxx>]
The date format is YYYYMMDDHH. The optional block [.N<xxx>]
marks the ensemble forecast number, where <xxx>
is the ensemble member number. The optional block [.<xxx>]
marks a pure forecast with <xxx>
being the forecast step.
Note
In the case of the new dis-aggregation method for precipitation, two new sub-intervals are added in between each time interval. They are identified by the forecast step parameter which is 0
for the original time interval and 1
or 2
for the two new intervals respectively.
fort files¶
There are a number of input files for the CONVERT2
Fortran program named
fort.xx
where xx
is the number which defines the meteorological fields stored in these files.
They are generated by the Python part of flex_extract
by just splitting the meteorological fields for a unique time stamp from the *.grb
files into the fort
files.
The following table defines the numbers with their corresponding content.
Number | Content |
---|---|
10 | U and V wind components |
11 | temperature |
12 | logarithm of surface pressure |
13 | divergence (optional) |
16 | surface fields |
17 | specific humidity |
18 | surface specific humidity (reduced gaussian) |
19 | vertical velocity (pressure) (optional) |
21 | eta-coordinate vertical velocity (optional) |
22 | total cloud water content (optional) |
Some of the fields are solely retrieved with specific settings, e.g. the eta-coordinate vertical velocity is not available in ERA-Interim datasets and the total cloud water content is an optional field for FLEXPART v10
and newer. Please see section ????????? for more information.
The CONVERT2
program saves its results in file fort.15
which typically contains:
Number | Content |
---|---|
15 | U and V wind components, eta-coordinate vertical velocity, temperature, surface pressure, specific humidity |
More details about the content of CONVERT2
can be found in Vertical Coordinate.
Note
The fort.4
file is the namelist file to drive the Fortran program CONVERT2
. It is therefore also an input file and is described in ???????????????
Example of a namelist:
&NAMGEN
maxl = 11,
maxb = 11,
mlevel = 91,
mlevelist = "85/to/91",
mnauf = 159,
metapar = 77,
rlo0 = -5.0,
rlo1 = 5.0,
rla0 = 30.0,
rla1 = 40.0,
momega = 0,
momegadiff = 0,
mgauss = 0,
msmooth = 0,
meta = 1,
metadiff = 0,
mdpdeta = 1
/