Content
The algorithm needs OASIS3 to work. There is a copy in the repository, which stems from TR32’s copy of the program.
COSMO outputs uses Grib data format (GRIB1 /GRIB2). The DWD GRIB 1 Library or the ECMWF GRIB_API are implemented in the COSMO model system. More details on COSMO Grib data can be found at the COSMO website or on the page “Coarse data”.
ecCodes
Instead of converting the Grib file to netCDF with an external tool, downscale[5] reads them directly, with ecCodes.
The ECMWF GRIB_API can handle both GRIB1 and GRIB2 data, but support for this interface will be discontinued from 2018 by ECMWF. And, ecCodes will be the replacement to handle the GRIB outputs. So, to handle Grib outputs, we make use of ecCodes available from:
https://software.ecmwf.int/wiki/display/ECC
There is also a mailing list.
Machine Specific Libraries
MPI on cluma2:
/daten01/z4/openmpi-1.4.3_intel_10.1/
/daten01/z4/openmpi-1.4.3_gnu
ecCodes on cluma2:
/daten01/z4/eccodes-2.3.0/lib/libeccodes_f90.so
The name of this directory gives rise to the suspicion that the employed ecCodes version is 2.3.0 of May 2017. On 2018-01-04 the current version is 2.6.0 of December 2017.
The [[job_script.sh]] will only work if the home folder contains a file " document:.cshrc" with the following paths setting:
setenv LD_LIBRARY_PATH /usr/lib64/openmpi/lib
setenv LD_LIBRARY_PATH /daten01/z4/eccodes-2.3.0/lib:${LD_LIBRARY_PATH}
setenv PATH /daten01/z4/eccodes-2.3.0:${PATH}
The latter two lines come at the suggestion of the Grib extension for downscale, along with the advice:
This will allow the use of extensive grib commands as well …
Namelist
Currently, there is no namelist for downscale. Across all parts of the program, there are flags ‘Dear user’ where changes have to be made after a migration to another machine, or to use other data. Users shall direct the program to their MPI in job_script.sh, and to the library ecCodes and the library to read NetCDF files in the makefile Makefile_oa3.