Brest, 29th November 2012

Argo programme : the « Deep Arvor » float challenges the limits of ocean observations.

Thanks to 3,000 profiling floats (small autonomous robots) measuring temperature and salinity from surface down to 2,000 meters on the global oceans, the international Argo programme, gathering more than 30 countries, has revolutionized global ocean observation. It is the first worldwide in situ ocean observation network that operates in near real time.

Deep Arvor, a new profiler, is pushing the limits of this observation down to 3,500 meters. In last August, for the first time, Deep Arvor tests allowed dives and measures at such a depth. Deep Arvor initiates a new generation of deep profiling floats with increased performance at a reasonable cost. This new generation meets the need to monitor deep water masses that have a key role in the study of climate change.

Deep Arvor was implemented by Ifremer in the frame of the Equipex NAOS project (Novel Argo observing system). NAOS results from a strong partnership between Ifremer), UPMC (co-coordinator), CNRS, PRES UEB (UBO/IUEM), SHOM1, and two private companies: CLS for satellite telecommunication aspects and the NKE SME which is in charge of the industrialization and commercialization of French Argo floats. NAOS aims at developing Argo technologies for the next decade.

Deep Arvor prototype is a technical challenge
In order to allow the Deep Arvor to measure deeper and to resist increasing pressure of 360 bars (pressure of 360kg/cm²), major improvements have been made on the float: salinity and temperature sensors, hydraulic engine, satellite, antenna, energy, etc.

The main innovation is the use of a light composite tube easy to manufacture. The float weight is 20-26 kg only and the measurement depth has been increased of 70% (from 2,000 to 3,500 meters).

Deep Arvor includes new features such as remote control, high resolution (sampling profile every meter). In addition to salinity and temperature, it is able to perform measurements of oxygen.

Deep Arvor should perform 150 cycles generating 150 profiles salinity, temperature and oxygen in a four year life time. Ifremer will transfer the Deep Arvor technology to its industrial partner NKE, who will manufacture and test two prototypes in 2013. A series of 24 deep floats will be tested by Ifremer in the North Atlantic Ocean in 2014.

NAOS strengthens Argo
The first objective of NAOS is to consolidate the French and European contribution to the Argo global observation system by deploying 10 to 15 additional floats each year from 2012 to 2019. Technological developments will be implemented to improve the reliability, lifetime, data transmission, energy efficiency and cost effectiveness and to expand on the operational capacity of the floats. They will be able to take deeper measurements and operate under ice in polar waters. Equipped with different sensors, they will perform more observations (dissolved oxygen, chlorophyll, nitrate).

NAOS benefits from a state aid from the French programme « Investissements d'Avenir » operated by the National Research Agency (ANR-10-EQPX-40).

Argo revolutionizes ocean research
Argo data, which are automatically transmitted by satellite to the Coriolis database available on the Internet, are effectively complementing satellite data to observe, understand, and, eventually, forecast the role of the ocean on the earth climate. They have already contributed to great improvements in the estimation of heat stored in the oceans. Argo data have been used to better understand mean sea level rise and to analyse large scale ocean circulation variations and deep convection areas. More than 200 scientific papers related to Argo data are published every year. This demonstrates the outstanding contribution of these new observations for ocean and climate research.

Key dates :

End of 1999 : First deployments of Argo floats.
November 2007 : The objective of 3000 deployed floats is reached. Since then, the number of operational floats has never been under 3000. They provide every year 100 000 temperature and salinity profiles.
January 2011 : NAOS successfully passed the first round of calls for proposals under the "Equipment of Excellence" (EQUIPEX) funding scheme.
June 2011 : EQUIPEX-NAOS project kick off.
June 2012 : First annual meeting of NAOS project in Brest.
Summer 2012 : Deep-Arvor, new generation float prototype, successfully tested.
December 2019 : End of NAOS project

For more information : ;;;

"Les Nouvelles de l'Ifremer" n°133 - July 2012 (in French) :


(1) Marine oceanographic and hydrographic services -


Press Office contacts:
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Ifremer - Johanna Martin – +33 (0)2 98 22 40 05 –
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