Validación de tres productos de precipitación en la costa ecuatoriana.

Abstract

Three precipitation products with global coverage have been analyzed for theEcuadorian coastal zone (below 1000 m above sea level), during the period 1964-1994, to evaluate their behavior and consistency, in addition to their response to thegoverning seasonal cycle. The precipitation products are: CRU (Climate ResearchUnit, University of East Anglia), GPCC (Global Precipitation Climatology Centre,Deutscher Wetterdienst), and UDEL (University of Delaware), regridded at a regulargrid of 0.25°. The reference dataset chosen (INMAHI12k) is based on observationsfrom 51 rain-gauges located at meteorological stations on the Ecuadorian littoral,gridded at 0.25°.The analysis is based, principally, on comparison of the products withthe observed annual cycle and total annual precipitation in previously defihomogeneous coastal precipitation zones, using bias, bias/error and correlationanalyses. Additionally, a Kruskal-Wallis test was executed over every grid point toassess the statistical differences between these products and reference dataset.Generally, the three products reproduced consistently the coastal annual cycle,however, from the statistical comparison we conclude that GPCC dataset is the onethat better adjusts to the observed precipitation regime. In addition, although the threeprecipitation datasets used in this study are all based on rain-gauge data from NationalMeteorological and Hydrological Services around the world, the data assimilation andprocessing systems (including the interpolation procedures) could explain thedifferences found between the products.