OSUG - Terre Univers Environnement

Le projet international TPOS2020

Séminaire de Sophie Cravatte, mardi 18 avril 2017 à 14h, salle Lliboutry

28 March 2017 ( maj : 30 March 2017 ), by Sandra Rome

A redesigned Observing System in the Tropical Pacific: the TPOS 2020 project
First report of recommendations and actions

Abstract: The tropical Pacific observing system (TPOS) has been the backbone of seasonal climate forecasting around the Pacific for 25 years, originally motivated by ENSO (El Nino Southern Oscillation). The TPOS 2020 project began as a response to the deterioration of the TAO/TRITON moored array in 2012-13, and has now expanded to a rethinking of the observing system as a whole. While the elements of the system were largely developed independently, we now envision an integration of platforms including the tropical moored arrays (TMA), Argo floats, and satellite capabilities, with each element contributing particular strengths.
In accord with this integrated view, TPOS 2020 is stepping back from the present grid-like configuration of the TMA, arguing that users of the system gain more value from data products that incorporate diverse sources of information. This requires that the models and data assimilation systems be considered vital elements of the network, and their advancement is crucial to the project success. New targets for improved understanding include the ocean mixed layer and the surface fluxes that interact with it; the diurnal cycle; equatorial ocean-atmosphere coupled physics; the Pacific boundary regions; and biogeochemistry, especially the large air-sea carbon fluxes. These requirements will be met by a combination of sustained and experimental networks.

A priority is to address differences among air-sea flux datasets over the tropics. Particular attention should be dedicated to obtaining accurate and unbiased surface wind/wind stress estimations. An immediate threat on the observing system is the degradation of the TRITON array in the western Pacific, and an appropriate strategy should be put in place to address it.

The rationale and recommendations for the redesign are described in a First Report of the TPOS 2020 project, available at

By Sophie Cravatte
Institut de Recherche pour le Développement, LEGOS, CNRS/CNES/IRD/UPS,Toulouse, France

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