Assessing the ability of three global reanalysis products to reproduce South American monsoon precipitation

摘要

The South American monsoon system (SAMS) refers to the strong seasonal variability in precipitation observed over South America, with high precipitation amounts during the summer while winter is the driest season. The aim of this work is to understand how different global reanalysis precipitation datasets (NCEP-2, ERA-Interim and CFSR-1) represent rainfall patterns and intensity associated with SAMS in comparison to gauge-based analysis (CPC). The results show that reanalysis products have some difficulties in simulating both spatial distribution and intensity of the observed precipitation. However, ERA-Interim seems to better correlate with the observed variability in precipitation during the austral warm season. The intensity and positioning of the 850-hPa moisture fluxes and the associated divergence patterns might explain differences found in precipitation from the three global reanalysis products in the SAMS core region.