For bias correction a merged observational grid has been created using the best resources available.

For global radiation the primary source is CARPATCLIM gridded observational dataset (Szalai et al., 2013 (www.carpatclim-eu.org); European Commission -JRC, 2015). Where no CARPATCLIM data is available, SARAH data (regridded with ESMF_RegridWeightGen) is used (Pfeifroth et al., 2017, doi:10.5676/EUM_SAF_CM/SARAH/V002). The SARAH data was regridded to the 0.1° grid with the method Higher-order patch recovery (patch) by Earth System Modelling Framework (ESMF) software ESMF_RegridWeightGen (http://www.earthsystemmodeling.org/esmf_releases/public/last/ESMF_refdoc/). For minimum and maximum temperature the primary source is CARPATCLIM gridded observational dataset (Szalai et al. , 2013 (www.carpatclim-eu.org); European Commission -JRC, 2015). Where no CARPATCLIM data is available, EOBS data (Version 16.0) is used (Heylock et al., 2008, doi:10.1029/2008JD010201; ECA&D, 2018). The EOBS data was regridded to the 0.1° grid with the method Higher-order patch recovery (patch) by Earth System Modelling Framework (ESMF) software ESMF_RegridWeightGen (http://www.earthsystemmodeling.org/esmf_releases/public/last/ESMF_refdoc/). For precipitation the primary source is DANUBECLIM gridded observational dataset (Szalai et al. , 2013 (www.carpatclim-eu.org); European Commission -JRC, 2015). Where no DANUBECLIM data is available, CHIRPS data is used (CHIRPS: Funk et al., 2015, doi:10.1038/sdata.2015.66). The CHIRPS data was regridded to the 0.1° grid with the method Higher-order patch recovery (patch) by Earth System Modelling Framework (ESMF) software ESMF_RegridWeightGen (http://www.earthsystemmodeling.org/esmf_releases/public/last/ESMF_refdoc/)., For mean 10-m wind speed the primary source is CARPATCLIM gridded observational dataset (Szalai et al. , 2013 (www.carpatclim-eu.org); European Commission -JRC, 2015). Where no CARPATCLIM data is available, ERA5 data is used (Copernicus Climate Change Service (C3S) (2017): ERA5: Fifth generation of ECMWF atmospheric reanalyses of the global climate). The ERA5 data was regridded to the 0.1° grid with the method igher-order patch recovery (patch) by Earth System Modelling Framework (ESMF) software ESMF_RegridWeightGen (http://www.earthsystemmodeling.org/esmf_releases/public/last/ESMF_refdoc/).

Regridding Method: Higher-order patch recovery (patch) by Earth System Modelling Framework (ESMF) software ESMF_RegridWeightGen (http://www.earthsystemmodeling.org/esmf_releases/public/last/ESMF_refdoc/)

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