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Revista Brasileira de Meteorologia

Print version ISSN 0102-7786

Abstract

QUADRO, Mario Francisco Leal de; DIAS, Maria Assunção Faus da Silva; HERDIES, Dirceu Luis  and  GONCALVES, Luis Gustavo Gonçalves de. Climatological analysis of the precipitation and umidity transport on the SACZ region using the new generation of reanalysis. Rev. bras. meteorol. [online]. 2012, vol.27, n.2, pp. 152-162. ISSN 0102-7786.  http://dx.doi.org/10.1590/S0102-77862012000200004.

The knowledge of the reanalysis performance and the systematic errors associated with them is extremely important in the acknowledgement of the physical processes occurring in the atmosphere. The goal of this study is to document the main characteristics of precipitation over the South Atlantic Convergence Zone (SACZ), based on six atmospheric reanalysis (MERRA, ERA-Interim, ERA-40, NCEP 1, NCEP 2 and NCEP CFSR) and five observed precipitation data products (SALDAS, CPC, CMAP, GPCP and GLDAS). Using the aforementioned available datasets the transport of moisture over SACZ was evaluated for the period of 1979 through 2007. In summary, the new generations of reanalyses show an improvement in the representation of the rainfall patterns and their magnitude. Taylor diagrams show that the observational products tend to be tightly grouped and close to the reference (CPC) point, whereas most of reanalyses show correlation coefficients below 0.6. NCEP CFSR reanalysis however, presented higher correlation coefficients relative to the others. Atlantic Ocean is the main moisture flux source to SACZ, which decreases towards the continent. Topography has an important role in moisture convergence over SE Region of Brazil. Over Amazon region, the convergence must be associated with thermodynamic processes.

Keywords : reanalysis; SACZ; precipitation.

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