High-resolution precipitation reanalysis over France through offline data assimilation in a downscalled ensemble meteorological reconstruction
Réanalyse haute résolution des précipitations sur la France en utilisant l'assimilation de données "offline" dans des reconstructions ensemblistes métrologiques provenant d'une descente d'échelle
Résumé
This study considers an "offline" data assimilation method using the Ensemble Kalman Filter to build a precipitation reanalysis over France. The method is here applied for reconstructing the 2009-2012 period, using past observation density of 1871, 1900 and 1950. The methodology allows taking two main features of precipitation into account: (1) an anisotropic localization matrix based on the climatological background information, (2) a Gaussian transformation applied to daily precipitation. Results show a reduced error and a reduced uncertainty compared to background reconstructions, even with few observations, thus demonstrating the added value of data assimilation.
Domaines
Sciences de l'environnementOrigine | Fichiers produits par l'(les) auteur(s) |
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