Urban climate evaluation in the upcoming generation of CMIP6-Driven EURO-CORDEX regional climate simulations

Source abstract

The latest EURO-CORDEX simulations, downscaling CMIP6 GCMs, provide an improved representation of urban areas compared to the previous CORDEX-CMIP5 generation, partly motivated by the increasing demand for urban-scale climate information for adaptation and planning, as reflected in the IPCC Special Report on Climate Change and Cities. In this study, we evaluate the ERA5-driven EURO-CORDEX ensemble (CMIP6 generation) for its ability to represent urban areas and simulate urban climate across nearly 100 European cities. We further assess the sensitivity of urban–rural contrasts to geographical location and urban parameterization schemes. Results show that the urban heat island effect is captured in most cities, with a more realistic representation in models that include urban canopy schemes. The urban dry island effect and wind speed attenuation are also identified, although they exhibit greater inter-model variability than temperature. Models identify spatial patterns across the analyzed cities, including geographical climatic gradients, the urban cool island effect in arid regions, and coastal influences. Comparison with observations highlights challenges in evaluating RCMs, underscoring the need for dense and representative observational networks or alternative approaches. This work provides the first systematic evaluation of urban climate representation in EURO-CORDEX, identifies suitable sub-ensembles, and informs future model development.