Climate change in the São Francisco river basin: analysis of precipitation and temperature

ABSTRACT Precipitation and temperature projections from global models, made available through the Coupled Model Intercomparison Project Phase 5 (CMIP5), and actually used in the AR5 by Intergovernmental Panel on Climate Change - IPCC-AR5), are assessed here for São Francisco River Basin. RCP 4.5 and RCP 8.5 are considered througout the period 2011 to 2100. Incidentally, global models are evaluated concerning their representativity related to 1961-2000 climatology from Brazilian National Meteorological Institute (INMET) data. Two indexes were evaluated: correlation and square mean error. The analisys of projections was performed through the assessment of yearly average values of 30 years period (2011-2040, 2041-2070 e 2071-2100). Additionally to evaluate trends and variability it was considered 10 year moving averages, linear regression and Mann-Kendall-Sen method. Approximately 28% analyzed models do not capture the seasonal precipitation reliably. All models present positive trend for temperature, and despite of divergence on precipitation, the models projected anomalies between -20 and 20 for each time-slice for this variable.