Heatwave/Coldwave recipe and 360-day calendars

[GarryHayman]

I am still relatively new to ESMValTool, although I have recently attended the advanced training. As part of the UK TerraFIRMA project, I am using the heatwave & coldwave recipe (recipe to analyse the TerraFIRMA overshoot runs.

I can successfully run the example recipe, which uses CMIP5 output for bcc-csm1-1 (on a 365-day calendar). However, all the TerraFIRMA heat wave/cold wave runs failed, apart from one. It is not clear to me why one of the periods worked and the rest did not, except that, apart from the historical runs, it is the earliest period (1979-2009). I also found similar behaviour when using the HadGEM3-GC31-MM CMIP6 datasets. The TerraFIRMA output uses a 360-day calendar. From the error message and subsequent debugging, I suspect that the errors are caused by the R Date conversion when using a 360-day calendar. I have raised an issue #4429 to provide further information.

Neither the Weigel et al paper on ESMValTool v2.0 https://doi.org/10.5194/gmd-14-3159-2021 nor the online documentation https://docs.esmvaltool.org/en/latest/recipes/recipe_heatwaves_coldwaves.html indicate any restrictions.

My question: is there a limitations in using this recipe with a 360-day calendar?

[rswamina]

@valeriupredoi - Can you please help with this?