Updates Readme

README.md

@@ -107,4 +107,10 @@ See the directory `boundary-data-remapped`.
 
 ## Analysis
 
-Example notebook for icon nextgems data is in `analysis/icon-nextgems/`. 
+Example notebook for icon nextgems data is in `analysis/icon-nextgems/`.
+
+## Preparing ICON-ESM input data
+
+On Teachinghub, see `~/LEHRE/msc-climmodlab-s2025/icon-r2b4-inputdata` for how the icon R2B4 grid looks like and how the SST and sea ice files look like.
+
+[CDO](https://code.mpimet.mpg.de/) might be helpful to remap from the Healpix grid to the R2B4 grid.