This paper analyses the changes in the atmospheric circulation pattern that can come happen in the climate of the South America (SA), as consequence of the increase in the concentrations of the C02. For this purpose 5 global models from IPCC AR4 (CCCMA, GFDL, HadCM3, MIROC and GISS) are utilized, for the periods of 1961-1990 (present climate - 20C3M) and 2011-2100 (SRESA2). Among, the models analyzed, the HadCM3 simulates the summer and spring circulation close to its observed, despite of locate the Bolivian High (BA) and the Chaco low (CL) shifted for the southwest of its climatological positions. On the other hand, for future scenarios the BA is shifted to west, and the CL is stronger and extends its over center of Brazil, generating underestimates the precipitation on the Amazonia. The GFDL model simulates better the precipitations in fall, over the north of the northeast Brazil. The subtropical highs of the north and south hemisphere show an adequate position to the location of the Intertropical Convergence Zone - ITZC (over 5°S). For future scenarios, this model does not change its circulation pattern, and in the last climatology (2071-2100), it generates positive anomalies over the north of the Amazonia. The GISS model simulates a summer and spring circulation far from its observed in the present climate. However, for the 2071-2100 future scenarios simulates a lot rain over the Amazonia.

Last Updated: 2007-12-14