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Test directory
The directory oifs/t21test contains a number of files:
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% cd oifs % ls t21test ICMGGepc8 ICMGGepc8INIUA ICMSHepc8INIT ifsdata namelists ref_021_0018 ICMGGepc8INIT ICMSHepc8 README job ref_021_0006 ref_021_0144 |
Files beginning with 'ICM'.
These are the input files for this T21 experiment. They are in GRIB format. Do not move them from this directory. OpenIFS expects to find it's input files in the same directory as the main executable.
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namelists
This file contains all of the input model fortran NAMELISTS. Not all of the namelists have their variables listed, only the variables commonly changed are listed here. Users should copy this file and modify it for the tests described below.
ref_021_*
These files are 0144
This file is reference output for the model tests. The model can be run in 'reference' mode where it checks it is working correctly by comparing some mathematical norms against these files. Reference runs are described in more detail under 'Acceptance testing' below.
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The model will expect to find a file called fort.4 in the same directory as the executable. This script copies the executable from oifs/make/build/bin.
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The model will fail with an error if it cannot find the 'ifs_samples' directory in the grib_api installation:
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If all these technical tests work, perform the acceptance tests below to ensure that the numerical results from the model are as expected. It's strongly recommended these tests are completed before proceeding to work with the model for development or production.
Acceptance testing
The final step is to check the model is producing the correct answers within acceptable limits, even if it runs the short tests above without failing. OpenIFS includes code that will compute internal statistical norms and compare against numbers supplied by ECMWF. The file: ref_021_0144 in the t21test directory contains statistical norms computed by the model run at ECMWF.
To do the acceptance test, edit the namelists in fort.4 and look for the NAMCT0 namelist:
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&NAMCT0
LREFOUT=false,
NSTOP=6, |
change the number of timesteps to 144 to run the model for 1 day (assuming you have not changed the default timestep of 10mins at T21) and set the LREFOUT to TRUE:
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&NAMCT0
LREFOUT=true,
NSTOP=144, |
With LREFOUT=true, at the last timestep OpenIFS will read the ref_021_0144 file and produce a new file: res_021_0144 (note the similar filenames!). The contents of the file should be:
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% cat res_021_0144
Results of ERROR calculation
The error calculated from the results shows
that the calculations are correct
The maximum error is = 0.11345 % |
As long as this error is less than 1% then the model is behaving satisfactorily.