83rd Annual

Tuesday, 11 February 2003: 4:30 PM
The global climate observing system. French contribution
Régis Juvanon du Vachat, Météo-France, Paris, France
France is participating fully in the Global Climate Observing System (GCOS). It incorporates the following four components: meteorological and atmospheric, oceanic, terrestrial, spatial, which will be briefly presented, especially in relation with the monitoring of the climate. The presentation will give an overview of the general principles governing the GCOS system and particularly the concepts used to maintain efficiently this climate observing system for a long period of time (“from research networks to operational networks”).The presentation will cover all the four components of the GCOS system, but for brevity the abstract is only devoted to the oceanic and terrestrial components. Indeed the whole report has been published in the French National Communication to the UNFCCC (United Nations Framework Convention on Climate Change).

The french contribution to oceanographic observation for climate comes under the GOOS system (Global Ocean Observation System) and contains the following: voluntary and occasional observation ships, ocean gauges, floating and anchored weather buoys and, finally, sub-surface floaters (Coriolis Project). We would like to emphasise the pre-operational direction of ocean observation, with Mercator modelling projects, the Coriolis observation project and the future data assimilation experiment, GODAE (2002-2004). The seven french agencies involved in oceanography (CNES, CNRS, IFREMER, IFRTP, IRD, Météo-France and SHOM) are joining forces to develop a complete and coherent system of operational oceanography based on three focal points: satellite altimetry (JASON), global numerical modelling with assimilation (MERCATOR) and in situ measures (Coriolis). The Coriolis project aims to construct a pre-operational structure for acquiring, collecting, validating and distributing world ocean data (temperature, salinity and current profiles) responding to the needs of modellers (MERCATOR) and of the scientific community (under CLIVAR).

The Global Terrestrial Network (GTN) deals with observation of mountain glaciers, long-term monitoring of greenhouse gases (RAMCES) and, finally, measurements of carbon fluxes linked to terrestrial ecosystems (FLUXNET). Mountain glaciers are thus studied in numerous parts of France and abroad, in particular by LGGE, IRD and CEMAGREF. The RAMCES network aims to understand greenhouse gas cycles and to provide a regional balance. France is also actively participating in measuring carbon flows in terrestrial ecosystems carried out under the international programme Fluxnet, and the various programmes connected with the Carboeurope project group. Forest ecosystems have also been systematically observed by the National Forestry Inventory (IFN) every ten years for almost forty years. A mechanism for monitoring environmental influences was also put in place after the damage caused by acid rain.

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