A spatio-temporal comparative study of the representation of precipitation over South America derived by three gridded data sets

Abstract

In the last few years, there has been an increasing application of gridded precipitation data sets for studies analysing seasonal and interannual precipitation variability as well as for performing validation analysis of climate and regional models. Consequently, the purpose of the present study is to analyse the representation of temporal variability and spatial patterns of precipitation in South America for the period 1971-2010, derived by three data sets based exclusively on rain gauge information (Climate Research Unit - CRU, Global Precipitation Climatology Centre - GPCC and University of Delaware - UDel), in order to identify discrepancies and/or agreements among them. Further analysis is performed for three particular sub-regions within the continent (southern sector of southeastern South America - SSESA, central South America - CSA and southeastern Brazil - SEBR). Results show that the three products represent key spatial features of precipitation analogously. Significant coherence in capturing the temporal variability, associated with the dominant modes of variability, is found in all sub-regions, though they differ largely in some areas, especially in CSA. Overall, depending on the region, the gridded products behave differently, without one particular data set standing out as an outlier in all the analysed cases.