An international array

Argo is a global array of 3,000 free-drifting profiling floats that measures the temperature and salinity of the upper 2000 m of the ocean. This allows, for the first time, continuous monitoring of the temperature, salinity, and velocity of the upper ocean, with all data being relayed and made publicly available within hours after collection. Since the 2000's, the physical state of the upper ocean is systematically measured and the data assimilated in near real-time into computer models. 

The ARGO broad-scale global array of temperature/salinity profiling floats has already grown to be a major component of the ocean observing system. The first Argo floats were deployed in late 1999, and by November 2012, Argo had collected its one million profile, twice the number obtained by research vessels during all of the 20th century !

>> know more on the origins of ARGO

>> description of all Argo floats


Figure :  The latest picture of the ARGO array (french contribution in yellow) 


CORIOLIS Contribution

Through the CORIOLIS structure, France is very active in all aspects of the Argo program : European coordination, data center (one of the two global processing centers), development of instrumentation at IFREMER and CNRS / LOV in partnership with NKE (floats and Provor Arvor), launching floats, research (ocean, climate, biogeochemistry) and oceanography (Mercator ocean Service Marine Copernicus). The NAOS Equipex project of the NAOS "Investments for the Future" program helps to prepare the future evolutions of Argo-France for the next decade.

1. CORIOLIS coordinates deployment activities and set up a team who prepares about 80 floats per year :  

  • prepare profilers (acceptance tests, programming, packaging, shipping) 
  • develop and update deployment plan profilers,  some times through opportunity vessels :

>> link to article  application/pdf Opportunity_Vessels_for_Coriolis_in_2012 637.45 kB 

  • ensure technical support and / or train teams for deployment
  • link with manufacturer
  • monitor sensors and float at sea performances using tools that allows the exploitation of meta-data and technical float data  as well as full documentation on the float for the manufacturer on configuration and manufacturer tests, users and other services> link to  « Argo float monitoring at sea »

2. in support to Data Management, CORIOLIS also operates one of the two European DACs and one of the two GDAC (Global Data Center for Argo)

Argo partners send the data to computer networks jointly run by the World Meteorological Organization and the Intergovernmental Oceanographic Commission within 24 hours of when the float transmitted the data.

>> Link to the Coriolis Data Center



Figure : Real Time and Delayed Mode ARGO data flow (© AIC)


3. Coriolis also contributes to improve the quality of the Argo data for Climate applications


Maintaining the array

The floats have an average life expectancy of about five years. To maintain the network, 800 to 900 floats are launched every year. Participating countries coordinate their deployment missions in an effort to maintain an average distance between floats of 300 kilometers :

Euro-Argo is the European contribution to the international ARGO network. The new ERIC (Euro-Argo Infrastructure Consortium) aims at developing an european infrastructure where the European partners have the capacity to procure and deploy about 250 floats per year (representing about 1/4 of the global array) and 50 additional floats per year for enhanced coverage in the European and Marginal Seas.

  • In France, Argo-France is organized through the Coriolis partnership (CNES, Ifremer, INSU, IPEV, IRD, Météo-France et SHOM). At regional scale, Argo France is supported by the IUEM Observatory (OSU IUEM) and was co-funded by the CPER of the Brittany region. A European Research Council (ERC) advanced grant has been also obtained by the Laboratoire of Villefranche to work on the development of a biogeochemical component for Argo


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