Lundi 3 octobre 2011- Séminaire -SWOT: The Surface Water and Ocean Topography Mission
de 11:00 à 13:00
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(Jet Propulsion Laboratory California Institute of Technology)
Titre : A multi-scale model for the Scheldt land-sea continuum
Résumé : SWOT, the Surface Water and Ocean Topography mission is a NASA/CNES joint mission that will nominally launch in 2019. SWOT serves two communities to address key unknown issues in geophysics and applications. For oceanographers, SWOT will provide the first measurements of sea surface height (SSH) able to resolve small mesoscale and submesoscale circulation, providing key measurements for understanding ocean mixing and dissipation. For hydrology, SWOT will provide the first global inventory of fresh water and global changes in water storage and discharge. In the first part of this talk, the SWOT mission will be reviewed, including the science objectives and the principles behind near-nadir radar interferometry, which allows the determination of water elevation with accuracies and spatial resolutions several orders of magnitude better than traditional altimetry. The design of the SWOT mission, including temporal and spatial sampling characteristics, the expected data products and their accuracies, and the calibration and validation plans will also be reviewed. The second part of the talk will concentrate on the feasibility of estimating river discharge from the SWOT data. River discharge is an essential component in understanding the flux of fresh water in the global water cycle. While SWOT does not directly measure discharge, it will be shown that by combining the water body elevation and extent measurements, together with dynamical multi-temporal constraints, it is possible, in principle, to recover hidden variables (river bathymetry and friction coefficient) that allow for the estimation of global instantaneous discharge. Recent progress towards achieving this goal and plans for future experimental demonstrations will be presented.
Ermesto Rodríguez has worked at the Jet Propulsion Laboratory, California Institute of Technology, since 1985. During that time, he has been one of the pioneers of radar interferometry, providing a theoretical basis and participating in missions such as the Shuttle Radar Topography Mission (SRTM). He is currently the mission architect for the SWOT mission and the project scientist for the NASA QuikSCAT mission. He has also contributed to radar altimetry, scatterometry, ice sheet sounding, and electromagnetic scattering theory.