Diurnal variation in stored energy flux in São Paulo city, Brazil

Abstract

This work describes the diurnal variation in energy flux storage in the city of São Paulo, Brazil. Monthly average hourly values for the storage of energy flux were estimated using the energy balance residual and parameterisation methods. The energy balance residual method used in situ observations of net all-wave radiation and turbulent fluxes of sensible and latent heat. The anthropogenic heat flux and horizontal net heat advection were not considered. The parameterisation method, based on the objective hysteresis model, used net all-wave radiation and land use information inferred from a 1-km radius area centred at the main observational site. Using the residual balance method, the maximum diurnal evolution in monthly average hourly values of energy flux storage occurred approximately 2h earlier than the net all-wave radiation. Using the parameterisation method to estimate energy flux storage, the daytime integrated values correspondedto approximately 51% of the net all-wave radiation and daily values to approximately 27%. The diurnal evolution in urban heat island intensity, based on monthly average values, reached a maximum intensity of 3.3°C and a minimum of, did not show a correlation with the energy flux storage during the time period considered in this work.