make (euro-)cordex work

[mwjury]

Since many many years ESMValTool is said to be able to handle CORDEX data, an indeed much has changed in the last ~2 years in this regard 👏 Thanks a lot!
This is just a request to make (euro-)cordex work, and to merge some of the open pull requests, in particular #1956.

I recently came back to ESMValTool which I learned to love (and hate), currently calculating some extreme indices over Europe from CMIP6 and CORDEX data. I just had a go at using the current EURO-CORDEX models for TAS, TASMAX, TASMIN, and PR, and I am very pleased I ran into little issues.
There are some related to dataset fixes, for which pull requests exist:

• GERICS-REMO2015 differences between original grid and standardised grid too large, addressed in Dataset problem: GERICS-REMO2015 differences between original grid and standardised grid too large. #2036, which would be fixed with cordex GERICS REMO2015 lon differences above 10e-4 #2334
• missing height coord in WRF381P, addressed in Dataset problem: Add height coord to ALADIN63 and WRF381P CORDEX datasets #2058, which would be fixed with cordex wrf381p: fix tas,tasmax,tasmin height #2333

and one that remains open:

• MPI-CSC - REMO2009 differences in the rotated grid as described in Dataset problem: GERICS-REMO2015 differences between original grid and standardised grid too large. #2036 (comment)

I did not run into missing height with ALADIN63 as described in #2058.

There is still quite an issue with RCMs using Lambert Projection grids (issue #1879, fix #1956). This is affected by contributions using ALADIN53, ALADIN63 and RegCM4-6 models (as well as IPSL-WRF381P, but only the MPI-M-MPI-ESM-LR r1i1p1 realization), making up roughly a sixth of the whole ensemble. The fix provided by @sloosvel and @Neah-Ko is ready since almost a year, but not merged.

Would you be able to help out?
Would you have the time and skills to implement the solution yourself?
I know I know, requesting features and not contributing is lame. I'm happy to contribute. My current contract concerning this is ~10hr a week running only for a couple of weeks which is a bit tight.

[bouweandela]

There is still quite an issue with RCMs using Lambert Projection grids (issue #1879, fix #1956). This is affected by contributions using ALADIN53, ALADIN63 and RegCM4-6 models (as well as IPSL-WRF381P, but only the MPI-M-MPI-ESM-LR r1i1p1 realization), making up roughly a sixth of the whole ensemble. The fix provided by @sloosvel and @Neah-Ko is ready since almost a year, but not merged.

If you could fix the merge conflicts and review the pull request (I imagine that would mean at least plotting data from all the affected datasets and checking that they are geographically in the correct place), the @ESMValGroup/technical-lead-development-team can merge the pull request for you. At the moment, no-one is funded to work on CORDEX support as far as I'm aware, though there is an interest from @ljoakim, @gnikulin, and @nhsavage.