Combining datasets of satellite retrieved products for basin-scale water balance study. Part II: Evaluation on the Mississippi Basin and closure correction model

Simon Munier (1, 2, 3) , Filipe Aires (3) , Stefan Schlaffer (4) , Catherine Prigent (3) , Fabrice Papa (2) , Philippe Maisongrande (2) , Ming Pan (5)

1 Estellus
2 LEGOS - Laboratoire d'études en Géophysique et océanographie spatiales
3 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique
4 TU Wien - Vienna University of Technology = Technische Universität Wien
5 Princeton University

In this study, we applied the integration methodology developed in the companion paper (Aires, 2014) by using real satellite observations over the Mississippi basin. The methodology provides basin scale estimates of the four water budget components (precipitation P , evapotranspiration E, water storage change ∆S and runoff R) in a two-step process: the Simple Weighting (SW) integration and a Post-processing Filtering (PF) that imposes the water budget closure. A comparison with in situ observations of P and E demonstrated that PF improved the estimation of both components. A Closure Correction Model (CCM) has been derived from the integrated product (SW+PF), that allows to correct each observation dataset independently, unlike the SW+PF method which requires simultaneous estimates of the four components. The CCM allows to standardize the various datasets for each component and highly decrease the budget residual (P −E−∆S− R). As a direct application, the CCM was combined with the water budget equation to reconstruct missing values in any component. Results of a Monte Carlo experiment with synthetic gaps demonstrated the good performances of the method, except for the runoff data that has a variability of the same order of magnitude as the budget residual. Similarly , we proposed a reconstruction of ∆S between 1990 and 2002 where no GRACE-data is available. Unlike most of the studies dealing with the water budget closure at the basin scale, only satellite observations and in situ runoff measurements are used. Consequently the integrated datasets are model-independent and can be used for model calibration or validation.

Domaines: Hydrologie

Simon Munier, Filipe Aires, Stefan Schlaffer, Catherine Prigent, Fabrice Papa, et al.. Combining datasets of satellite retrieved products for basin-scale water balance study. Part II: Evaluation on the Mississippi Basin and closure correction model. Journal of Geophysical Research: Atmospheres, 2014, 119, pp.100-116. ⟨10.1002/2014JD021953⟩. ⟨hal-01162534⟩