SEASONAL VARIATION OF SURFACE ENERGY BALANCE OF A CENTRAL BRAZIL CITY

Abstract This intense growth and populational concentration experienced by Cuiabá City since the 70's has favored to the rapid process of land cover changes on local tropical climate mainly because the replacement of preserved natural areas by building and impervious surfaces. Based on this scenario, this research aimed to evaluate the surface-atmosphere exchanges of an urban site located near downtown of Cuiaba City. In general, the fraction of flux partitioning of anthropogenic heat flux (QF), heat stored inside the urban canopy (ΔQs), latent heat fluxes (QE) and sensible heat fluxes (QH ) corresponded to 3, 26, 28 and 46 % and 3, 23, 31 and 46% of energy available in the environment (Q*+QF) , in the dry and wet season respectively. These fractions of the energy balance were similar to those observed in Miami City, but differ in terms of the timing of the peak and the intensity. The average diurnal Bowen ratios (β) in the dry and wet seasons were 1.67 and 1.55 and showed directed relation with decreasing vegetation cover area. Sensible and latent heat fluxes were positively correlated with impervious surface and vegetated area.