ICON v2.6.6 Patch: for flexible SSTs in nested domains

Patch Content

The patch allows to run ICON version v2.6.6 in a nested setup in which SSTs vary with time. As prerequisite, the SST time series need to be prepared for each nest independently. 

The setup was tested with daily updated SST from ERA5.

Patch Extraction

1. get correct ICON version (access restricted due to licensing)

git clone git@gitlab.dkrz.de:icon/icon-mpim.git --branch icon-2.6.6 --recurse-submodules 

2. download patch
wget -O icon-2.6.6-patch_sst-in-nests.patch "https://zenodo.org/records/18385022/files/icon-2.6.6-patch_sst-in-nests.patch?download=1"


3. apply patch

cd icon-mpim
git apply ../icon-2.6.6-patch_sst-in-nests.patch --whitespace=nowarn

4. build and compile
./config/dkrz/levante.intel
make -j16

Runscript Changes

The user needs to change to following (example uses two nests and SST in Sept. 2020):

1. link sst files, e.g. 
    ...
    # SST/SIC data
    sst_sic_data_path=${grids_folder}
    sst_file1=sst_sic_DOM01.nc
    sst_file2=sst_sic_DOM02.nc
    sst_files="'${sst_file1}', '${sst_file2}'"
    add_link_file $sst_sic_data_path/sst_sic_2020-09_DOM01.nc ${sst_file1}
    add_link_file $sst_sic_data_path/sst_sic_2020-09_DOM02.nc ${sst_file2}
    ...
 2. provide sst files through namelist
    &lnd_nml
    ...
     sstice_mode                 =                          6         ! 6: SST and sea ice fraction are updated with user-defined interval
     sst_td_filename             =                      ${sst_files}
     ci_td_filename              =                      ${sst_files}
    /

Patch Creation 

The patch has been created with 

 git diff  release-v2.6.6...icon-2.6.6_sst-in-nests > ../icon-2.6.6-patch_sst-in-nests.patch

Acknowledgements

The development was supported by the IFCES2 project was funded by BMFTR (formerly known as  BMBF - Federal Ministry of Education and Research) under grant number 16ME0689K as part of the SCALEXA funding initiative, which in turn was funded by the European Union - NextGenerationEU.