Folder setup

The code is structured with base folder Med12 and inside it is found:

• nemo-src, containing the source code of nemo v4.0.7;
• data-static, containing all those input fields that are not required to change during execution;
• data-dynamic, containing conversely all those data that change from run to run (forcings, lateral boundary conditions and so on)
• preprocessing-[era5, cmecs], all the scripts necessary to retrieve data and process them to finally put them into data-dynamics. This structure is represented in the following tree.

.
└── Med12/
    ├── data-dynamic/
    │   ├── era5/
    │   └── cmecs/
    ├── data-static/
    │   ├── basin_mask.nc
    │   ├── ...
    │   ├── domain_cfg.nc
    │   ├── ...
    │   ├── weights_ERA5-MED7km_bicub.nc
    │   └── weights_ERA5-MED7km_bilin.nc
    ├── med12-src/
    │   └── ...
    ├── nemo-src/
    │   ├── arch
    │   ├── ...
    │   ├── src
    │   ├── test
    │   └── tools
    ├── preprocessing-era5/
    │   ├── grib/
    │   │   └── *.grib (raw data)
    │   ├── run/
    │   │   └── *.run (download scripts)
    │   ├── tools/
    │   │   └── *.F90 (process raw data into NetCDF)
    │   └── fetch-and-process.py
    └── preprocessing-cmecs

This structure will be referred throughout these instructions and can be built with the following commands:

export ROOT=$HOME
# Base folder
mkdir -p $ROOT/Med12
# Folder for static data
mkdir -p $ROOT/Med12/data-static
# Folder for dynamic data
mkdir -p $ROOT/Med12/data-dynamic
mkdir -p $ROOT/Med12/data-dynamic/era5-atmos
mkdir -p $ROOT/Med12/data-dynamic/cmecs-latbnd
# Folder for the nemo source code
mkdir -p $ROOT/Med12/nemo-src
# Folders for atmospheric forcing preprocessing
mkdir -p $ROOT/Med12/preprocessing-era5/grib
mkdir -p $ROOT/Med12/preprocessing-era5/run
mkdir -p $ROOT/Med12/preprocessing-era5/tools
# Folders for lateral boundary conditions preprocessing
mkdir -p $ROOT/Med12/preprocessing-cmecs

Med12 configuration setup

The configuration is described in Storto et. al. https://gmd.copernicus.org/articles/16/4811/2023/gmd-16-4811-2023.html

installation can be done with the following steps

cd $ROOT/Med12
svn co https://forge.ipsl.jussieu.fr/nemo/svn/NEMO/releases/r4.0/r4.0.7/ nemo-src/

It is important to stick with version 4.0.7, version 4.0 does not work

To create the configuration MED12

cd cfgs
cp -r AMM12 MED12
cd MED12
echo "bld::tool::fppkeys key_mpp_mpi key_asminc" > cpp_MED12.fcm

then remove top from cpp_MED12.fcm copy EXPREF into compile

Retrieving and processing forcing fields

Prerequisites

sudo apt-get install cdo nco

Atmospheric forcing: ERA5 from Copernicus Climate Data Store, readme (instructions)

• 2m temperature
• 10m $u-$component of wind
• 10m $v-$component of wind
• snowfall
• surface solar radiation downwards
• surface thermal radiation downwards
• total precipitation

Lateral boundary conditions: CMEMS from Copernicus Marine Service, readme (instructions)