Assessing the performance of the CERRA dataset in reproducing precipitation and extreme precipitation events over the Iberian Peninsula

Study region: The Iberian Peninsula (IP). Study focus: Understanding precipitation and extreme precipitation events is crucial for managing climate impacts on human activities, ecosystems, and environment. Reanalysis datasets such as ERA-Interim and ERA5 are commonly used to studying these patterns; however, their spatial resolution often limits their accuracy. The recent high-resolution Copernicus European Regional ReAnalysis (CERRA) product provides an opportunity to improve precipitation estimates, particularly in regions with complex topography. The present study aims to assess the performance of the CERRA dataset in representing precipitation and extreme precipitation events across the IP. The analysis involves a comparison between CERRA and observational datasets, focusing on several annual and seasonal spatial precipitation indices. Special attention is given to the representation of extreme precipitation and their associated trends. New hydrological insights for the region: The results indicate that CERRA effectively captures the spatial distribution of precipitation across most seasons, with weaker performance during the summer. CERRA reliable represents extreme precipitation and their temporal trends across the IP, especially in regions with complex orography such as Galicia and the Pyrenees. However, it tends to overestimate precipitation in drier areas. Trend analysis also revealed that, while CERRA successfully reflects the general patterns of precipitation extremes, some discrepancies remain, especially in autumn. Overall, CERRA demonstrates strong potential as a valuable dataset for hydrological and climatological studies over the IP.