Title
New statistical methods for precipitation bias correction applied to WRF model simulations in the Antisana Region, Ecuador
Date Issued
01 December 2018
Access level
open access
Resource Type
journal article
Author(s)
Heredia M.B.
Prieur C.
Condom T.
Université Grenoble Alpes
Publisher(s)
American Meteorological Society
Abstract
The Ecuadorian Andes are characterized by a complex spatiotemporal variability of precipitation. Global circulation models do not have sufficient horizontal resolution to realistically simulate the complex Andean climate and in situ meteorological data are sparse; thus, a high-resolution gridded precipitation product is needed for hydrological purposes. The region of interest is situated in the center of Ecuador and covers three climatic influences: the Amazon basin, the Andes, and the Pacific coast. Therefore, regional climate models are essential tools to simulate the local climate with high spatiotemporal resolution; this study is based on simulations from the Weather Research and Forecasting (WRF) Model. The WRF Model is able to reproduce a realistic precipitation variability in terms of the diurnal cycle and seasonal cycle compared to observations and satellite products; however, it generated some nonnegligible bias in the region of interest. We propose two new methods for precipitation bias correction of the WRF precipitation simulations based on in situ observations. One method consists of modeling the precipitation bias with a Gaussian process metamodel. The other method is a spatial adaptation of the cumulative distribution function transform approach, called CDF-t, based on Voronoï diagrams. The methods are compared in terms of precipitation occurrence and intensity criteria using a cross-validation leave-one-out framework. In terms of both criteria, the Gaussian process metamodel approach yields better results. However, in the upper parts of the Andes ( > 2000 m), the spatial CDF-t method seems to better preserve the spatial WRF physical patterns.
Start page
2021
End page
2040
Volume
19
Issue
12
Language
English
OCDE Knowledge area
Estadísticas, Probabilidad Oceanografía, Hidrología, Recursos hídricos Meteorología y ciencias atmosféricas
Scopus EID
2-s2.0-85059937641
Source
Journal of Hydrometeorology
ISSN of the container
1525755X
Sponsor(s)
Acknowledgments. Within the CDP-Trajectories frame-work, this work is supported by the French National Research Agency in the framework of the ‘‘Investisse-ments d’avenir’’ program (ANR-15-IDEX-02). The first author M.B.H. was funded by the IRD program LMI-GREATICE and the OSUG@2020 labex. The simulations presented in this paper were performed using the Froggy platform of the CIMENT infrastructure (https:// ciment.ujf-grenoble.fr), which is supported by the Rhône-Alpes region (GRANT CPER07_13 CIRA), the OSUG@2020 labex (reference ANR10 LABX56), and the Equip@Meso project (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche. The authors thank INAMHI (Ecuador), Luis Maisincho, SNO GLACIOCLIM, and Antoine Rabatel for the in situ stations data. The authors also thank Gérémy Panthou (IGE) and Théo Vischel (IGE) for useful discussions.
Sources of information: Directorio de Producción Científica Scopus