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Vous êtes ici : Accueil / Actualités / Séminaires / Seminaires Septembre 2018-Aout 2019 / Jeudi 14 Février - Satellite dataset integration for terrestrial water cycle analysis and water storage change reconstruction

Jeudi 14 Février - Satellite dataset integration for terrestrial water cycle analysis and water storage change reconstruction

Par SEMSOU Dernière modification 14/01/2019 09:18
Quand ? Le 14/02/2019,
de 11:00 à 12:00
Où ? salle Jules Verne
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Victor Pellet

Post-doctorant au LERMA-Observatoire de Paris et Estellus, Paris


Titre : Satellite dataset integration for terrestrial water cycle analysis and  water storage change reconstruction

 

Résumé : During the last decades, Earth Observations (EO) have increasingly been used to study global hydrology. However, using EO to study the water cycle is still a challenge, at the regional as at the global scale: EO suffer from numerous systematic and/or random errors and they are often not coherent with each other (Pellet and Aires. 2018). In particular, they generally do not close the water cycle budget. It is however possible to optimally merge several datasets for each component of the terrestrial water cycle to close this budget at the basin scale, using only EO and no model assimilation (Aires et al. 2014; Munier et al. 2015). When considering enough basins and associated river discharges to constrain a closed domain such as the Mediterranean region, it is possible to develop a dedicated integration technique that closes simultaneously the terrestrial, oceanic and atmospheric water cycle budgets (Pellet et al. 2019). Once a reference dataset is obtained to describe the water cycle in a hydrologically coherent way, it is possible to design an independent and simple calibration of each satellite dataset to reduce the overall budget residual, over long time series, and with the original EO spatial resolution. We show that this global calibration transforms the original datasets towards a consensus that is hydrologically more coherent, with reduced budget residuals (Pellet et al. 2019). This allows for instance for the reconstruction of a missing water component such (Munier et al. 2017). This approach has opened new perspectives to generate for example long-term estimate of the water storage change in the large Himalayan river basins (Pellet et al. in preparation). In this presentation, we will introduce these merging techniques and illustrates the concepts over the Mediterranean region and some major Asian basins.

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