Instead of interpolating extpar, we try to add the T_SEA variable on the original grid's extpar.

conf/event-generator/simulation.yml

@@ -7,7 +7,8 @@ simulation:
   radiation_grid_filename: icon_grid_0015_R02B05_R.nc
 
 #  external_parameters_filename: icon_extpar_0010_R02B04_G.nc
-  external_parameters_filename: icon_extpar_0024_R02B06_G_20200917_tiles.nc
+#  external_parameters_filename: icon_extpar_0024_R02B06_G_20200917_tiles.nc
+  external_parameters_filename: icon_extpar_0016_R02B06_G_20131206.nc
   date_format: '%Y-%m-%dT%H:%M:%SZ'
   namelist_paths:
     # Path to the namelists

templates/event-generator/adapt_member.sh

@@ -48,7 +48,12 @@ interpolate_SST "${DESTINATION_GRID}" "${SST_FORCING}" "${INTERPOLATED_SST}"
 
 
 # Interpolate extpar
-interpolate_extpar "${DESTINATION_GRID}" "${EXTERNAL_PARAMETERS_FILE}"
+#interpolate_extpar "${DESTINATION_GRID}" "${EXTERNAL_PARAMETERS_FILE}"
+
+
+# Integrate sst to extpar
+integrate_sst_to_extpar "${INTERPOLATED_SST}" "${EXTERNAL_PARAMETERS_FILE}"
+
 
 
 # Integrate sst to analysis

templates/event-generator/adapt_member_utils.sh

@@ -133,3 +133,40 @@ END
   python integrate_sst_to_analysis.py
 
 }
+
+function integrate_sst_to_extpar() {
+  local INTERPOLATED_SST="$1"
+  local EXTERNAL_PARAMETERS_FILE="$2"
+
+  cat <<END >integrate_sst_to_extpar.py
+# Add sst field to analysis file.
+from enstools.io import read
+import os
+import numpy as np
+
+os.environ['ECCODES_GRIB_NO_INDEX'] = '1'
+# Open files
+with read("${EXTERNAL_PARAMETERS_FILE}") as ds, read("${INTERPOLATED_SST}") as sst_ds:
+  da = sst_ds["T_SEA"]
+  year = 2000 # or any other year
+  dates = [(datetime(year, 1, 1) + timedelta(days=idx)).month for idx, _ in enumerate(da['time'].values)]
+
+  da['time'] = dates
+
+  # Replace analysis T_SEA with monthly mean from the sst_ds.
+  monthly_means = [da.sel(time=month).mean(dim="time") for month in range(1,13)]
+  concat_da = xr.concat(monthly_means, dim='time')
+  concat_da['time'] = np.arange(1, 13) # replace 'time' with month numbers
+  concat_da = concat_da.drop(['clon', 'clat'])
+
+  # Replace analysis T_SEA with monthly mean from the sst_ds.
+  ds["T_SEA"] = concat_da
+
+  ds.to_netcdf("extpar.nc")
+
+END
+
+  python integrate_sst_to_extpar.py
+
+}
+