Once a year in April, Mercator Ocean in Toulouse and the Coriolis Infrastructure in Brest publish a common newsletter. Some papers are dedicated to observations only, when others display collaborations between the 2 aspects: Observations and Modelling/Data assimilation.

The two first papers are presenting two Equipex funded projects in order to better observe the ocean: The IAOOS Ice Atmosphere Ocean Observing System over the Arctic Ocean (http://wwww.iaoos-equipex.upmc.fr) and the NAOS (Novel Argo Ocean Observing system) (Le Traon et al.).

Then D’Ortenzio et al. are writing about the PRONUTS project aiming at autonomously profiling the nitrate concentrations in the ocean. During this project, two prototypes of PRONUTS will be developed and tested.

Next paper deals with a global glider infrastructure (EGO) for the benefit of marine research and operational oceanography (Testor et al.). Some key challenges have emerged from the expansion of the glider system and require now setting up a sustainable European as well as a Global system to operate glider and to ensure a smooth and sustained link to the Global Ocean Observing System (GOOS).

Vialard et al. are then displaying results about the Cirene oceanographic cruise, the part of the CLIVAR international effort to understand air-sea interactions at multiple time scales in the “Thermocline Ridge of the Indian Ocean” TRIO region.

Speich et al. follow with a paper about the use of ARGO floats to study the ocean dynamics south of Africa: what have been learnt from the Good-Hope project and what is planned within the SAMOC international programme.

Rio et al. then write about the use of altimetric and wind data to detect the anomalous loss of SVP-type drifter’s drogue. They have developed a methodology that allows detecting the drifter drogue loss and providing an estimate of the wind slippage to be used as a velocity correction.

Surface salinity drifters for SMOS validation are also presented by Morisset et al. The surface drifters measuring sea surface salinity (SSS) in the top 50cm of the sea surface provide a complementary source of data for validating L-band sea surface salinity.

At last, a new information and data mining tool for North Atlantic Argo data is presented by Maze. This new tool aims at providing an interactive user interface for Argo data mining, simplifying access to information about all, or a sub-set of, profiles and centralizing as much as possible infor-mation provided by other services.

We will meet again next year in April 2013 for a new jointly coordinated Newsletter between Mercator Ocean and Coriolis. Note that there will not be exceptionally any publication of the newsletter in July this year. The next October 2012 issue will be about the NEMO ocean code recent devel-oppements.

We wish you a pleasant reading,

Laurence Crosnier and Sylvie Pouliquen, Editors.

• NAOS: preparing the new decade for Argo.
• Ice, Atmosphere, Ocean Observing System: the EQUIPEX-funded IAOOS project.
• Autonomously profiling the nitrate concentrations in the ocean: the pronuts project.
• EGO: Towards a global glider infrastructure for the benefit of marine research and operational oceanography.
• Cirene: from cyclones to interannual timescales in the south-western tropical Indian Ocean.
• Use of ARGO floats to study the ocean dynamics south of Africa: what we have learned from the GoodHope project and what we plan within the SAMOC international programme.
• Use of altimetric and wind data to detect the anomalous loss of SVP-type drifter’s drogue
• Surface salinity drifters for SMOS validation
• A new information and data mining tool for North Atlantic Argo data