Avaliação das projeções para a sazonalidade da precipitação dos modelos do IPCC-AR4 para o cenário A1B sobre o Nordeste brasileiro

Abstract

The projections of rainfall provided by global models in the fourth report of the Intergovernmental Panel on Climate Change (IPCC) for the A1B scenario are assessed for the Brazilian Northeast as the changes in seasonality. The assessment consists of the calculation of precipitation anomalies in all models for the periods from 2010 to 2039, from 2040 to 2069 and from 2070 to 2099 in relation to the 20C3M scenario simulations during the period from 1901 to 1999. The models agree that there will be no abrupt changes in the percentage contribution in the amount of monthly rainfall annually, with anomalies reaching a maximum of 7% in the rainy season and 2% in the dry season. The average of the models in the three periods shows a slight intensification in the pre-season and in the rainy season. The BCCR_BCM2_0 and CNRM_CM3 models indicate an increase in rainfall in the months December-January-February. On the other hand, the MIROC3_2_MEDRES and UKMO_HADCM3 models indicate significant reductions in virtually all year.