About RESTART

Brief description of the project

The Urban Heat Island (UHI) occurs when an urban area is significantly warmer than its rural surroundings due to human activities. UHIs are more frequent and intense in inland metropolitan cities, worsening as the size of the urbanised area increases and where there is less greenery. In recent years, an increase in the UHI intensity has been experienced, related to the increasing urbanisation, together with a growth in the intensity, frequency, and duration of heat-waves that is expected to worsen with global warming. Similarly to UHI, the Urban Pollution Island (UPI) identifies the onset of spatial/temporal variations in pollutant concentrations attributable to typical urban features and activities. The UHI-UPI interaction is an important issue not yet fully elucidated, and represents an ongoing challenge to make cities more resilient. RESTART aims at investigating the connection between UHI and UPI, offering a series of urban mitigation strategies including tailored Nature-Based Solutions (NBS), such as green areas and roofs, trees, green walls, and ready-to-use guidelines for the improvement of well-being in urban environments. RESTART has selected the city of Rome as a pilot city but aims at providing a set of tools that can be transferred to other Mediterranean cities.

The Italian capital, chosen as an open-air laboratory, aims to be a place where scientists and stakeholders can study and collaborate to provide a set of tools replicable in other urban settings on the Mediterranean area, as well as essential information to favour the ecological transition and the improvement of the quality of life in terms of livability of urban spaces, with important social and economic impacts.

The project activities are divided into two main phases. The first was focused on determining the state of the art of the UHI and UPI in Rome, analysing the meteorological processes affecting these phenomena and identifying possible links between them, highlighting how severe pollution events and heat waves interact and possibly trigger their occurrence. The most critical aspects were identified exploiting the observations collected by the already existing monitoring networks in the Rome territory. Ground-based atmospheric monitoring instruments, belonging to international observatories and dense networks of instruments, provided quality-checked datasets of WMO-compliant meteorological and air quality measurements. In the second phase, the vulnerabilities identified in the first step will drive the numerical investigation of city-scale ventilation, heat transport, and air pollutant removal. The most up-to-date numerical modelling chains combined cutting-edge numerical simulations with mesoscale and dispersion models to simulate the connection between UHI and UPI, both in the pre- and postmitigation tools implementation scenarios. The thermodynamic and chemical processes that govern UHI and UPI will be analysed in detail, focusing on thermal comfort, pollutants dispersion and deposition, and photochemical ozone reactions. The impacts of the implementation of different mitigation solutions on both UHI and UPI effects were also explored. The outcomes, obtained from the combination of numerical and experimental analysis, are used to formulate general recommendations and guidelines that will be disseminated within the scientific community, population, and policymakers.

In a nutshell

PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE – Bando 2022

• Duration: 24 + 6 months, from 28·09·2024 to 28·02·2026

• ERC fields: Meteorology, atmospheric physics and dynamics (PE10_2); Physical Sciences and Engineering (PE); Atmospheric chemistry, atmospheric composition, air pollution (PE10_1); Climatology and climate change (PE10_3)

• Keywords: Urban Heat Island; Urban Pollution Island; Mitigation strategies; Atmospheric physics; Urban environment; Climate change