Data for: Deep-learning downscaling of CMIP6 heatwave projections for Greece and comparison with a regional climate model

This dataset accompanies the paper “Deep-learning downscaling of CMIP6 heatwave projections for Greece and comparison with a regional climate model” (Fragkoulidis, Kyros, Kyriakou, Darmaraki, Kotroni, and Lagouvardos, submitted to Natural Hazards and Earth System Sciences). Daily mean 2-m temperature from five CMIP6 global climate models (CMCC-ESM2, EC-Earth3, INM-CM5-0, MPI-ESM1-2-HR, MRI-ESM2-0; member r1i1p1f1) was downscaled over Greece from 1° to 0.05° (about 5 km) with a U-Net trained on the CERRA reanalysis. It was then bias corrected toward CERRA with empirical quantile mapping (1985–2014) and quantile delta mapping (2051–2080), using a 31-day window. Heatwaves are defined as at least three consecutive days in May–September with daily mean temperature above the calendar-day 95th percentile of 1985–2014. Each dataset uses its own historical thresholds, which are kept fixed for the future. Contents Heatwave number, duration and intensity for: CERRA (1985–2014); for 1985–2014 and for 2051–2080 under SSP2-4.5 and SSP5-8.5: the five GCMs at 1°; the DL downscaling and bilinear interpolation (0.05°), each with and without bias correction; the ICON-CLM regional climate model driven by MPI-ESM1-2-HR (0.11°), with and without bias correction. The heatwave thresholds of all these products. Daily mean 2-m temperature (May–September) for the five GCMs and the three periods, from: the DL downscaling, with and without bias correction; the bias-corrected interpolation. Evaluation with CERRA as the truth, using inputs built by upscaling CERRA to 1°: daily 2024 fields of CERRA, DL, DL with bias correction, interpolation and bias-corrected interpolation (2024 was withheld from training); maps of the mean absolute error on the test days of 1985–2023. The tables behind the figures and tables of the paper (CSV). Greek land masks, and the CERRA orography. All gridded files are in NetCDF4 format. See README.md for the file list, the grids and the variable definitions.