Linking urbanization with air pollution and thermal environment in Bucharest metropolis

In frame of the global warming and urban growth, Bucharest residents and its ecosystem will be more vulnerable to increased levels of air pollution and heat stress related to urban heat island (UHI) effect and the increased frequency and duration of heat waves (HWs) during summer June-August months. The response of air quality to climate change is an increasing concern at both the local and global levels. This study examined the response of urban thermal environment to air pollution and climate variability in Bucharest, Romania, from a spatiotemporal perspective during the 2020-2023 period. Through synergy use of time series of geospatial and in-situ air pollution (particulate matter PM2.5 and PM10, O3, NO2, SO2, CO), and climate data in relation with derived vegetation biophysical variables, this study developed a complex statistical and spatial regression analysis. Was quantified air pollution relationship with urban thermal environment defined by land surface temperature-LST and air temperature at 2m height AT. Green space was measured with MODIS Terra satellite-derived normalized vegetation index- NDVI, which captures the combined availability of urban parks, street trees, forest, and periurban agricultural areas. A distinct spatiotemporal difference across the urban/periurban gradient, air temperature -TA and land surface temperature -LST anomalies is associated with urbanization-induced climate warming, especially during summer UHIs and HWs. The findings of this study contribute to developing advanced models to predict air pollution impacts on urban heat under future urbanization, and also in urban planning for better mitigation and optimizing air quality in future green cities.