Urban climate assessment in the ABC Paulista Region of São Paulo, Brazil.

This article aims to map the urban climate in the ABC Paulista (ABCP) region, which is located in the southeast area of the Metropolitan Region of São Paulo (MRSP), Brazil. More than 80% of the ABCP urban area comprises the municipalities of Santo André (SA), São Bernardo do Campo (SBC), São Caetano do Sul (SCS), Mauá (MA), Diadema (DIA), and Ribeirão Pires. Considering a four-year dataset (2015–2018), higher urban heat island (HI) intensities were found in the spring (3.7 °C) and summer (3.2 °C), in DIA and SCS, and these HI intensities were associated with extreme thermal discomfort in the afternoon. More intense and concentrated rainfall patterns over a shorter period were identified in ABCP, especially in DIA and SCS. An analysis of O3 and PM10 at fixed pollutant monitoring stations identified SBC as having the largest number of days with O3 concentrations beyond the standards; meanwhile, SCS significantly exceeded the PM10 standards. The traffic and transportation simulation tool, Equilibre Multimodal/Multimodal Equilibrium which was used to estimate emissions from mobile sources, identified SCS as having the highest emissions rates for CO2, CO, HC and PM10. Analysis of the rainwater composition in Capuava (located along boundary of SA and MA) and Paranapiacaba (an environmental preservation area of SA) identified that a major contribution of strong acids and heavy metals in Capuava possibly originated from the Capuava Petrochemical Complex. Meanwhile, the main source of pollutants in Paranapiacaba was from the industrial city of Cubatão. Principal component analysis identified the first three components, which explained 80.7% of the total variance of the data and the main urban climate processes. The HI intensity was associated with thermal discomfort; moreover, the PCA showed the inverse correlation between the number of days that O3 and PM10 exceeded the limits with low relative humidity and no precipitation.