Characterization of the autumn Iberian precipitation from long-term datasets: comparison between observed and hindcasted data

The present paper is focused on the analysis of the characterization of the autumn precipitation regime over the Iberian Peninsula. To this aim, different long-term, observed, hindcasted and reanalysed datasets are used to analyse the 41-year (1961-2001) time period. A long-term high-resolution precipitation database, derived from more than 4000 in situ observational stations, is used to characterize the rainfall regime. This observational data, used as a reference, allows the verification of the realism of different existing long-term hindcasted and reanalysed products. These verification and comparison exercises were carried out with the autumn monthly hindcasted data derived from the high-resolution Mediterranean Hindcast of Dynamic Processes of the Ocean and Coastal Areas of Europe (HIPOCAS) database, as well as the NCEP and ERA global reanalysis data. The characterization of autumn Iberian rainfall is carried out, both in terms of spatial and time variability, by means of spatial distribution of different statistics and a principal component analysis (PCA), as well as through an analysis based on wavelet methodology. The statistical comparative analysis between the HIPOCAS and the observed precipitation data shows a noticeable agreement existing between both datasets, highlighting that the Mediterranean HIPOCAS hindcast database is a useful tool that is able to accurately reproduce and largely capture the main spatial and time features that regionally configure the Iberian rainfall regime along the studied 41-year period. Moreover, it is verified that the hindcasted HIPOCAS data notably improves the characterization of the autumn Iberian precipitation provided by the aforementioned global reanalysis products, asserting that the HIPOCAS precipitation dataset can well be used in regional studies related to hydrometeorology, statistical downscaling and climate variability. Copyright (C) 2008 Royal Meteorological Society