Analysis of PMIP3 Simulations on the Brazilian Northeast for the Pre-Industrial and Middle Holocene Period

Abstract The present work shows a comparison between simulation data from PMIP (Paleoclimate Modelling Intercomparison Project Phase III) for the pre-industrial climate against observations from CMAP (Climate Prediction Center Merged Analysis of Precipitation) and Climatic Reserch Unit (CRU) for precipitation and reanalysis data from NCEP/NCAR for the 2 m air temperature over the following regions: Northeast Brazil (NEB) (46° W - 34° W: 16° S - 2° S), in order to find a subset of models with a realistic representation of current climate. Following, a comparison was done between results for the pre-industrial (PI) period and the mid-Holocene (MH, ~6.000 years before present), with the objective of identifying possible climatic changes between those two periods over South America. Among the twenty-two models in PMIP3 dataset, ten models were selected for analysis, since the show, for the pre-industrial period, a better representation of observed features, such as the annual cycle over the regions and spatial patterns typical of the current climatology of South America. Those PMIP3 models suggest that current climate and MH climate exhibit important differences regarding the intensity of the South America monsoon system (weaker MH monsoon compared to present).