Exploring Madrid’s Local Climate: The Impact of Urban Development and Thermally-Driven Flows

Madrid's population has doubled, over the past five decades (1970–2020), while its urban area has expanded fivefold. By 2037, projections estimate further urban growth of 1.15 to 2.14 times compared to 2010, alongside a 15% population increase (INE, 2022). This rapid urbanization alters mesoscale and local atmospheric circulations, degrades air quality, increases energy consumption, and intensifies the Urban Heat Island (UHI) effect.

This study evaluates the impact of Madrid’s urban expansion on local meteorology using the mesoscale WRF model with BEP-BEM urban parameterization (Martilli et al., 2002; Salamanca et al., 2010). Urban parameters are integrated based on the city’s growth from 1970 to 2020. Results show that areas with increased urban fraction experience higher near-surface air temperatures, especially at night. Urbanization modifies the Surface Energy Balance (SEB) and turbulent transport. These findings underscore the role of urban-induced changes in local meteorology and highlight the need for climate adaptation strategies to mitigate the effects of urban expansion on air quality and thermal comfort in Madrid.

In this work, we will also present the recently funded MULTIURBAN-II (" Impacts of mesoscale thermally-driven flows on the urban heat island, local meteorology, and air quality in complex environments in the city”) research project. This project analyzes the dynamic and thermal impacts of these flows in different city zones, the role of turbulent mixing, their effects on UHI, and broader implications. To achieve these objectives, both field campaign data (including radiative and turbulent fluxes in urban and rural environments) and numerical simulations from the WRF model will be used.