Skip to main content

Global Ocean Observing Infrastructure

Final Report Summary - EURO ARGO (Global ocean observing infrastructure)

ARGO is an international global ocean observing system (GOOS) based on an array of some 3000 autonomous floats drifting freely in the world's oceans. Those floats, which probe the water to a depth of 2000 m and report temperature and salinity data to land stations, constitute one of the essential components of the global climate observing system. They also provide invaluable data in support of ocean and climate research, operational oceanography and ocean monitoring. The system is implemented by a large number of agencies and scientists in over 40 countries. A high level of coordination is necessary to organise efficiently the operations at sea, maintain the array and to perform the required tasks of data management (e.g. collection, validation and quality control, distribution and availability and safe keeping).

The main objective of the EURO-ARGO consortium is to organise and consolidate the European contribution and to set up a research infrastructure in support of the global ARGO programme. EURO-ARGO having been endorsed by the European Strategic Forum on Research Infrastructures (ESFRI), the preparatory phase project had several objectives to progress towards defining the appropriate legal framework and to address several critical technical points related to instrumentation and sensors, data management and array design. Capacity building and outreach have also been given due consideration. The most important results of the project can be summarised as follows.

After extensive review of possible legal frameworks for the EURO-ARGO RI, it has been decided to adopt the European Research Infrastructure Consortium (ERIC) status. Since this is a new concept (which was elaborated by the commission during the course of the project) it has taken some time to obtain agreement by the project participants to join in the consortium. The EURO-ARGO ERIC statutes have been drafted, including the governance structure, which consists of a council, a management board, a programme office and a scientific and technical advisory group. The EURO-ARGO ERIC will include members and observers. Budgets have been proposed for the first five years, with an examination of the anticipated expenses and possible sources of national and international funding.

It has been agreed that the research infrastructure will be distributed, with national activity centres and the central research infrastructure (the ERIC) to be established in France at Ifremer. As of the end of the project, France, Germany, United Kingdom (UK), Italy, Spain, the Netherlands, Bulgaria and Greece will be members and Ireland, Poland, Portugal will be observers. The draft statutes have been endorsed by the French ministries and forwarded to the commission for review.

The technical activities of the project considered the status of float technology and its likely evolution over the coming years (design, lifetime, cost, new sensors, improved telecommunications, etc.). A comparative evaluation has been made of new sensors like oxygen (O2) and bio-geochemical sensors, ice sensing algorithms, vertical sampling strategy, transmission systems (ARGOs and Iridium), batteries etc. A comparison of the performances of different types of floats (Provor, Nemo and Apex) has also been made. Sampling strategies for the Nordic, Mediterranean and Black seas have been examined. Four aspects of data processing and distribution system have been considered: enhancement of the mandatory functions related to ARGO regional centres both in Nordic seas and in Mediterranean and Black seas; the development of new tools to help float deployment plans and monitor the behaviour at sea; definition of real-time quality control procedures for biochemical data; and improvements of the consistency of the ARGO dataset.

Finally, a European ARGO user group has been set-up, outreach activities have been carried out in the Black sea; an educational website has been posted with pedagogical and illustrative material on ocean dynamics, observations and the ARGO system.

Project context and objectives:

The context:

Global change is one of the most pressing issue and concern that mankind is facing in this century. Burning fossil fuels releases huge amounts of green house gases into the atmosphere, which affect the radiative balance and lead to global warming. The impact on society is potentially highly damaging and irreversible; this poses a formidable challenge to the policy makers and citizens of the world. Decisions and actions to alter the present course taken by humanity should be taken on the basis of sound scientific knowledge, not only in the fields of Earth sciences (hydrology, climatology, oceanography, glaciology, meteorology, soil, ecosystems), but also in the humanities (political and social sciences, economics, demographics).

In this very complex system, the ocean plays a key role by its ability to absorb, transport and/or release green house gases, heat and water and redistribute them on the Earth surface. The ocean also reveals the impact of climate change. There is increasing evidence that sea level is rising at an accelerating rate of 3 mm/year, the Arctic sea ice cover is shrinking and high latitude areas are warming rapidly. These effects are caused by a combination of long-term climate change and natural variability.

Lack of sustained observations of the atmosphere, oceans and land has hindered the development and validation of climate models. For instance, there is an ongoing controversy on the transport of heat northwards in the Atlantic and its influence on western European climate: has it weakened by 30 % in the past decade, as some scientists claim (a result based on just five research cruises spread over 40 years), or was this change part of a trend that might lead to a major change in the Atlantic circulation, or due to natural variability that will reverse in the future, or is it an artefact of the limited observations?

Collecting the observations necessary to understand the ocean role in the climate system and in climate change, is a task accessible only to those few research groups having access to research vessels. There is a need for systematic global ocean observations, providing high quality data and information products to research groups in Europe and elsewhere.

An infrastructure for global in situ ocean observations:

The EURO-ERGO infrastructure (see online) will be a major component of the ARGO global in situ ocean observatory. The ARGO network is a global array of autonomous instruments, deployed over the world ocean, reporting subsurface ocean properties to a wide range of users via satellite transmission links to data centres. It is now the major and only systematic, source of information and data over the ocean's interior. The international ARGO programme was initiated in 1999 as a pilot project endorsed by the Climate Research Programme of the World Meteorological Organisation (WMO), the GOOS and the Inter-governmental Oceanographic Commission. The ARGO ocean observatory must be considered in its ensemble: not only the instruments, but also the logistics necessary for their preparation and deployments, field operations, the associated data streams and data centres and the interfaces with research and operational user communities. The objective of EURO-ARGO is to develop and progressively consolidate the European component of the global network. The European contribution should be of the order of a quarter of the global array. Specific European interest also requires a somewhat increased sampling in regional seas (Nordic, Mediterranean and Black seas). Overall, the EURO-ARGO infrastructure will comprise 800 floats in operation at any given time. Given the average float life time (presently below four years), the maintenance of such an array requires Europe to deploy about 250 floats per year.

A unique contribution to global ocean and climate research and environmental monitoring

ARGO measures temperature and salinity over the upper 2000 m of the ocean. These two essential climate variables describe the oceans' physical and thermodynamic state. The ARGO array is thus an indispensable component of the GOOS required to understand and monitor the role of the ocean in the Earth's climate system, in particular the heat and water balance. The sampling characteristics allow for the first time the resolution of seasonal and inter-annual variability of the global ocean circulation. Through ARGO the systematic estimation of the heat and fresh water budgets (storage, transport and atmospheric fluxes) is now possible. ARGO is strongly complementary to satellite observations; to use a meteorological analogy, satellite altimetry provides the equivalent of the atmospheric pressure field and ARGO profiles are the equivalent of the radio-sounding network. ARGO data are readily assimilated with those from satellites into ocean circulation and climate models, in support of research and operational applications. The proposed contribution to the ARGO array is integrated into the Global Monitoring for Environment and Security (GMES) and the Global Earth Observing System of Systems (GEOSS).

Advanced instrumentation for worldwide coverage:

The instruments are autonomous floats, battery powered, with a design life of between four and five years. The sensors provide high accuracy, high resolution measurements, which are transmitted in real time. One of the key objectives is to provide truly global coverage, in particular in the southern hemisphere which, prior to ARGO, was direly under-sampled. It was estimated that some 3 000 floats in operation would be required to reach that objective. ARGO's goal is to build and maintain the 3 000 float array. Success in such a major undertaking can be achieved only through a very high degree of international cooperation and integration. That is why EURO-ARGO proposes to build up and maintain a major node in the global network, with a European contribution of 800 floats.

Support to the users

Two broad classes of users of EURO-ARGO are identified: the scientific community and the operational services for ocean monitoring (e.g. ocean and climate forecasting centres). While the former require uniform validated data sets of the highest quality, the latter place the emphasis on the real time efficient delivery of quality controlled data. EURO-ARGO responds to those requirements by adopting the open data policy of ARGO, free for all users, with user-friendly data formats and delivery. An integrated data management system is developed, which includes:

1. one of the two ARGO global data assembly centres, in charge of data collection, validation, distribution and archiving;
2. specialised Atlantic and southern ocean regional data centres, providing integrated data sets, delayed mode quality control;
3. a full range of services including elaboration of value added data syntheses (climatology, ocean indicators), array monitoring, expertise on instruments and sensors, coordination of field operations, resources on complementary data sets, integration into the international network and ARGO management (project office, ARGO steering team, ARGO information centre).

Project objectives

The main objective of the EURO-ARGO preparatory phase project was to undertake the work needed to ensure that by 2012 Europe will be able to deploy, maintain and operate an array of 800 floats. This requires Europe to deploy some 250 floats per annum worldwide. Moreover, EURO-ARGO will provide a world-class service to the research (climate) and environment monitoring (e.g. GMES) communities.

The main expected outcome of the preparatory phase proposal was to reach an agreement between member states and other funding agencies for long term (more than 10 years) operation of EURO-ARGO (financial, governance, organisation, technical). To reach such an agreement, it has been necessary to work on several key technical (float technology, data management and delivery system) and organisational (logistics for deployment, coordination of national contributions) issues; to consolidate and broaden the user community; and to demonstrate further the impact and utility of the infrastructure for Europe.

The preparatory phase was structured along several work-packages focusing on:

1. consolidation and strengthening of existing national contributions to the infrastructure
2. development of a direct European Community (EC) wide contribution through GMES
3. development of legal and governance arrangements for the EURO-ARGO infrastructure
4. evaluation and improvement of the European contribution to the ARGO data management and delivery system
5. enhancement of European float technological capabilities (performances, sensors, communication systems) and working towards using ARGO to study aspects of ocean biogeochemistry
6. development of a vigorous European ARGO user community
7. using open access to ARGO data as an educational 'window' on the oceans and their role in climate
8. development new partnerships between European ARGO nations, new European countries and nations outside Europe
9. integration of the European observing array into the international system.

Potential impact:

Toward a sustained contribution of Europe to ARGO:

The international ARGO project is a presently at a critical juncture where strategic decisions have to be taken. The observatory has been developed progressively over the years on a best effort basis, in a very mixed context of mostly research funds, with rather limited sustained operational funding. Now that the array has reached its nominal size of 3000 floats in operation that data centres are effectively collecting and distributing high quality data and that the project has demonstrated its ability to detect critical ocean processes, the main challenge is to transition to a permanent infrastructure for ocean and climate research and monitoring.

Monitoring of the global climate system requires long term, high quality time observations. The critical question is to transition from a research project to a sustained, long term, observing system. Research projects have a relatively short time span and are strongly dependent on the individual scientists who conduct them. A permanent observatory must have the proper organisational back-up, funding basis and institutional framework to operate independently of the individuals involved.

In order to optimise the investment and to operate the infrastructure most efficiently, a high degree of integration is necessary. The project has succeeded in establishing a research infrastructure in which agencies from twelve countries will coordinate their efforts and resources to contribute effectively to the ARGO programme. They share a vision for the strategic and tactical choices that must be made. Finally, a continuous feedback with the scientific community has been initiated with the creation of the user group, so that science users can express their requirements with respect to the observing array design.

ARGO is an ambitious project that is breaking new ground in the widespread deployment of low cost autonomous instruments in hostile environments. Technology development in a European context will be a specific beneficiary of the results of the project.

Specifically, the emphasis on building and sustaining the array in a cost-effective manner places particular emphasis on monitoring the performance of all European deployed instruments and hence learning how to diagnose incipient float failure and using this to improve float design. The effort to increase the effectiveness and throughput of delayed mode data quality control will have significant benefit in learning how sensors perform and degrade following long exposure to bio-fouling and pressure/temperature cycling.

The formation of a EURO-ARGO users group provides an effective forum for the discussion of these issues between users and between users and float and sensor manufacturers. Since one of the commercial float manufacturers is European, this information could provide a competitive advantage.

Finally, EURO-ARGO provides encouragement for the participation of new and small European nations in the use of the float technology and in the use of ARGO data.

Specific benefits from building a long-term European infrastructure for ARGO:

The specific benefits from building a European infrastructure for ARGO are expected to include:

1. greater efficiency in float procurement as the smaller countries will be able to rely on EURO-ARGO for specifying their floats, procuring their floats and potentially benefit from price reductions associated with larger orders;
2. EURO-ARGO will provide a central capability for float testing and preparation and storage which will mean that new participants do not have to invest in technical staff or storage facilities;
3. stronger European coordination of float deployments will ensure that certain areas are not overpopulated at the expense of others or the global array;
4. strengthening the European ARGO data processing centres;
5. providing a mechanism for developing consistent inputs and a more concerted European voice into the international ARGO programme, hence giving a stronger European influence on how ARGO develops in the future;
6. EURO-ARGO will deliver a stronger and more coherent European contribution to float technology development, with particular emphasis on European needs leading to improved capability, performance and lifetime;
7. through EURO-ARGO it will be possible to sustain and build upon the European ARGO users' group established during the preparatory phase in order to ensure that users' needs are articulated and that the best scientific and technical advice continues to feed into EURO-ARGO;
8. it will also provide the means to sustain important outreach activities needed to explain to schoolchildren and the general public the importance of observations from the oceans towards dealing with climate change and other environmental issues;
9. EURO-ARGO will play a leading role in extending float coverage into the Nordic Seas and Arctic Ocean, regions which are presently outside of the 'core' ARGO design but which have a significant impact on the Atlantic circulation and climate change impacting western Europe;
10. a stronger European contribution to ARGO will also be a major contribution towards sustaining the global float array, which has been shown to be an essential core element of our ability to run predictive climate models (e.g. on seasonal to decadal timescales) and to run operational models (e.g. for the GMES marine service) for ocean analysis and prediction.

The collection of ocean observation from research vessels is accessible only to a few major marine institutes which have the ability to organise and conduct research cruises. Systematic in-situ global ocean observations are presently available only through the ARGO array. There is no doubt that the EURO-ARGO research infrastructure will greatly contribute to foster active research programmes in Europe in the fields it aims to serve: ocean science in general and more particularly the role of the ocean in the global climate system. By providing adequate networking and cooperation between Member States, it will contribute to the development of Europe excellence in ocean and climate research. The open policy on data access, which is easily and freely available, is aimed to facilitate the development of vigorous and successful research by a wide ocean scientific community in Europe.

GMES and the marine service:

ARGO is the single most important in-situ observing system for the GMES marine service and its MyOcean project. Based on the combination of space and in situ observations and on data assimilation, MyOcean provides information on the ocean for the large scale (worldwide coverage) and regional scales (main European basins and seas): temperature, salinity, currents, ice extent, sea level, primary ecosystems.

The targeted applications belong to four main areas:

1. marine safety (e.g. marine operations, oil spill combat, ship routing, search and rescue);
2. marine resources management (e.g. fish stock management);
3. climate and seasonal forecasting (e.g. climate change monitoring, ice seasonal forecasting);
4. marine and coastal environment (e.g. water quality, coastal activities).

ARGO delivers critical data (especially over the vertical dimension of the oceans) for assimilation in MYOCEAN ocean models. Without ARGO and a strong European contribution to ARGO, MYOCEAN modelling and assimilation systems will thus not be sufficiently constrained and will not be able to serve several key applications.

The United Nations Framework Convention on Climate Change (UNFCCC) and the global Earth observation system of systems:

The EURO-ARGO project can be seen as one of the actions that the European Union (EU) and participating member states are taking to fulfil their obligations under several conventions and international treaties.

The EU is a signatory to the UNFCCC, which includes (article four), a commitment to:

1. promote and cooperate in scientific, technological, technical, socio-economic and other research, systematic observation and development of data archives related to the climate system and intended to further the understanding and to reduce or eliminate the remaining uncertainties regarding the causes, effects, magnitude and timing of climate change and the economic and social consequences of various response strategies;
2. promote and cooperate in the full, open and prompt exchange of relevant scientific, technological, technical, socio-economic and legal information related to the climate system and climate change and to the economic and social consequences of various response strategies;
3. promote and cooperate in education, training and public awareness related to climate change and encourage the widest participation in this process, including that of non-governmental organisations.

Its article five is fully devoted to research and systematic observation.

All of those commitments underpin the EURO-ARGO terms of reference and have been included ab initio in its design, data policy and data system architecture, as well as in several actions initiated under the EURO-ARGO preparatory phase project.

Similarly, the group on Earth observations (GEO) was launched in response to calls for action by the 2002 World Summit on Sustainable Development and by the group of eight (G8) and in the spirit of the UNFCCC. These high-level meetings recognised that international collaboration is essential for exploiting the growing potential of Earth observations to support decision making in an increasingly complex and environmentally stressed world.

GEO is a voluntary partnership of governments and international organisations. It provides a framework within which these partners can develop new projects and coordinate their strategies and investments. As of March 2011, GEO's members include 86 governments and the EC. GEO is constructing GEOSS on the basis of a 10 year implementation plan for the period 2005 to 2015. The plan defines a vision statement for GEOSS, its purpose and scope, expected benefits and the nine 'Societal benefit areas' of disasters, health, energy, climate, water, weather, ecosystems, agriculture and biodiversity.

In this somewhat complex architecture of system of systems is the global climate observing system and its ocean component, the GOOS, all of which have strongly endorsed ARGO as a high priority programme. Indeed, one can readily see how ARGO fits into a vision that will go towards meeting several of the societal benefit areas:

1. reducing loss of life and property from natural and human-induced disasters, through applications of the GMES marine core services (e.g. ocean surface conditions for hurricane prediction);
2. improving the management of energy resources, ocean knowledge necessary for off-shore operations such as deep sea oil, or wind turbines;
3. understanding, assessing, predicting, mitigating and adapting to climate variability and change, where ocean observations are indispensable;
4. improving water resource management through better understanding of the water cycle, upper ocean knowledge for understanding air sea interaction and the evaporation / precipitation balance (e.g. monsoons);
5. improving weather information, forecasting and warning, obvious need for ocean data;
6. improving the management and protection of terrestrial, coastal and marine ecosystems;
7. understanding, monitoring and conserving biodiversity, including ocean biodiversity (e.g. impact of ocean acidification).

Other international conventions or directives, the European marine strategy:

There are numerous international conventions covering the marine environment, all of which call for the implementation of ocean monitoring systems and strong research programmes. For instance, the convention for the protection of the marine environment of the north-east Atlantic (Ospar) is the current legal instrument guiding international cooperation on the protection of the marine environment of the north-east Atlantic (the EC, representing the EU, is among the participants). The convention includes a strategy for the joint assessment and monitoring programme, which assesses the status of the marine environment and follows up implementation of the strategies and the resulting benefits to the marine environment. Although this is not a separate strategy, the Ospar commission has also considered the relevance of climate change issues in a wider context.

Another example is the EU's ambitious Marine Strategy Framework Directive (adopted in June 2008) to protect more effectively the marine environment across Europe. It aims 'to achieve good environmental status of the EU's marine waters by 2020 and to protect the resource base upon which marine-related economic and social activities depend. The Marine Strategy Framework Directive constitutes the vital environmental component of the Union's future maritime policy, designed to achieve the full economic potential of oceans and seas in harmony with the marine environment.'

The main dissemination activities:

The main tool for the dissemination and exchange of information among project partners and other interested parts is the EURO-ARGO website at

Contact: Pierre-Yves Le Traon (project coordinator), Emina Mamaca (project officer)

Address: Ifremer, BP 70, F-29820 Plouzané


Related documents