Project MCITY Brazil: Assessing Urban Climate Features of São Paulo and Rio de Janeiro

The project MCITY Brazil aims to characterize the micrometeorological features of urban climate of two major urban areas of Brazil: The metropolitan regions of São Paulo and Rio de Janeiro Cities. They were chosen as the starting point in this project because they are the largest conurbations of Brazil. Altogether, they occupy approximately 13,733 km2 with a population of 31.6 million inhabitants and a fleet of 10.6 million vehicles. These two metropolitan areas contribute to almost 45% of the Brazilian gross domestic product. Three micrometeorological platforms were set up in São Paulo (rural, suburban and urban) and one in Rio de Janeiro (suburban) measuring major components of surface energy balance (net radiation, soil heat flux, sensible and latent heats). Four field campaigns were carried during 2013 where radiosondes were released every 3 hours during 10 days in Summer (February 9-28 in São Paulo, 12-21 March in Rio de Janeiro) and Winter (July 9-18 in Rio de Janeiro and August 6-15 in São Paulo). During these field campaigns a LIDAR was used to obtain the PBL temporal evolution in both Cities. This work describes the major features of energy balance at the surface in São Paulo and Rio de Janeiro. Special attention will be given to the methodology used to estimate the turbulent fluxes and the vertical extent of the PBL. The mean thermodynamic and moisture structures of the PBL are presented and their relation with the observed turbulent fluxes of sensible and latent heat is explored. The mean dynamic structure of the PBL is analysed including the presence of low level jet and the sea breeze. The time evolution of the São Paulo UHI mean intensity is described and its nature is reviewed considering as reference the available literature.