Land use change over Amazon Forest and its impact on the climate.

This study describes the physical processes associated with the impact of the Amazon (AMZ) deforestation on the climate in the north-northwest sector of South America (SA). Two simulations with RegCM4, from 1979 to 2009, were carried out: one using a default land cover map (CTRL) and other one using deforestation scenario (LUC), i.e., all broadleaf evergreen trees tropical were changed by C3 grass. RegCM4 was integrated with a horizontal grid spacing of about 50 km and considering 18 sigma-pressure vertical levels for SA CORDEX domain. The lateral and boundary conditions for driving the model were obtained from the ERA-Interim reanalysis. The climate change signal due to AMZ deforestation was evaluated by comparing the climatology of the CTRL with the LUC experiment. AMZ deforestation causes a dipolar response in the precipitation consisting of reduced (increased) precipitation over western (eastern) side of the basin. Concerning the temperature, there is a warmer anomaly over the deforested areas, and it contributes to decrease the surface pressure. The higher air temperature is associated with an increase of the sensible heat flux and a decrease of the latent heat flux over the deforested areas.