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GENERAL CONTEXT

The oceans contain some 50 times as much carbon dioxide as the atmosphere, and small changes in the ocean carbon cycle can therefore have large atmospheric consequences. Such changes are believed to have had important feedback effects on climate during the transitions to and from ice ages; they may also have important consequences for the global climate and environment, and for many human activities in the next 50-100 years, as a result of rapidly rising levels of atmospheric carbon dioxide and other greenhouse gases. Models indicate that the oceans are currently taking up at least a third of the anthropogenic carbon dioxide by dissolving it into water that then loses contact with the atmosphere because of sinking or vertical mixing. Biological processes complicate the oceanic carbon cycle although they probably do not affect much the present uptake of anthropogenic carbon dioxide. Nevertheless, they are important because they (1) are the determinant of the natural background distribution of carbon; (2) complicate our efforts to measure the background distribution due to the seasonal variation in biological processes; and (3) have the potential to amplify chemical and physical effects, via biological feedbacks in the system.

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HISTORICAL BACKGROUND

The role of the ocean in controlling climate change through the storage and transport of heat (and liquid water) was recognised early on by the World Climate Research Programme (WCRP) and led to the planning of the Tropical Ocean-Global Atmosphere (TOGA) study and the World Ocean Circulation Experiment (WOCE). In parallel to these initiatives, the Joint SCOR (Scientific Committee on Oceanic Research) and IOC (International Oceanographic Commission) Committee on Climatic Change and the Ocean (CCCO) proposed a global survey of the oceanic carbon dioxide (CO2) budget field, and WOCE agreed to accommodate a small CO2 programme on the ships taking part in the WOCE Hydrographic Programme (WHP). At that time, marine geochemists and biologists were also concerned that a physical transport model with only an upper boundary condition would be inadequate to determine the role of the ocean in the atmospheric carbon dioxide budget and hence the prediction of climate change in response to the atmospheric build-up of greenhouse gases would not be possible. These concerns were articulated at a NATO meeting in 1982 on the chemistry of the upper ocean (Brewer, 1986) and at a workshop in the USA in 1984 (GOFS, 1984). The proceedings of these meetings provided the initial scientific focus and framework for ocean biogeochemistry and various national programmes.

As early as 1986, several European countries were nationally planning ocean studies with a focus on the carbon cycle and flux from the surface to the deep ocean and sediments. However, to determine global net fluxes and the processes controlling them was beyond the capability of any one nation. Shortly thereafter in February 1987, the formal organisation of JGOFS emerged under the Scientific Committee on Oceanic Research (SCOR). Sponsored by SCOR and the International Council of Scientific Unions (ICSU), leading experts in the ocean carbon cycle met in Paris and agreed upon the goals, scientific elements, topics of emphasis and organisational structure of JGOFS (SCOR, 1987), and in October 1987, the Executive Committee of SCOR approved an international planning committee for JGOFS that met for the first time in January 1988. Later the same year, JGOFS assumed responsibility for the carbon dioxide measurements programme and formed the Joint JGOFS-CCCO Advisory Panel on Carbon Dioxide.

At the turn of the decade, Germany was planning an extensive research cruise in the North Atlantic to commemorate the centennial of Hensenīs Plankton Expedition. JGOFS seized this opportunity to organise its first regional process study on the German R/V "Meteor", which led to the JGOFS North Atlantic Pilot Study in 1989. The participating countries were Germany, UK, Netherlands, USA and Canada. To further establish its position in the international communities, JGOFS also sought programme links with other global studies under ICSU and WCRP, such as the formal agreement between SCOR and the International Geosphere-Biosphere Programme (IGBP) in 1989. Under that agreement, JGOFS became a core project under IGBP, but responsible directly to SCOR.

Initially, the Scientific Steering Committee (SSC) for JGOFS created a number of Planning Groups and Task Teams to consider scientific and logistic questions and make recommendations to the SSC. These groups helped to identify and plan the most important processes and variables to study, the ocean regions that such studies should provide the greatest insight and most useful data, and the best experimental design for the studies. The SSC would then identify the sequence of events necessary to complete specific tasks, the resources required for the tasks and the level of international co-ordination that is required. During JGOFS field studies, more than twenty countries contributed to JGOFS SSC and helped to plan and coordinate the fieldwork. As task teams and planning groups completed their terms of reference, they would eventually disband after delivering their final reports, while others, such as the Data Management Task Team, would continue throughout JGOFS fieldwork and later synthesis. The following scientific goals of JGOFS were published in its Science Plan:

SCIENTIFIC GOALS

bullet_s To determine and understand on a global scale the processes controlling the time-varying fluxes of carbon and associated biogenic elements in the ocean, and to evaluate the related exchanges with the atmosphere, sea floor and continental boundaries
bullet_s To develop a capacity to predict on a global scale the response to anthropogenic perturbations, in particular those related to climate change

To accomplish these scientific goals, JGOFS restricted itself to the most important tasks consistent with its lifetime and resources, i.e., carbon exchange between the atmosphere and ocean. However, for periods longer than a year, the main factors limiting this flux may be associated with the exchange of carbon between the upper ocean and the ocean interior. JGOFS had therefore adopted the following "operational goal" for evaluating components of the project:

OBJECTIVES

bullet_s an assessment of large-scale carbon fluxes, obtained from a greatly increased network of observations;
bullet_s a set of models that express our understanding of the processes controlling large-scale carbon fluxes;
bullet_s a procedure for observing the ocean in a routine, synoptic manner to detect possible changes in the ocean carbon cycle in response to climate change;
bullet_s a well-cared-for data set, comprising observations made according to standard protocols and a system for making subsets of these easily available to researchers;
bullet_s a better knowledge and understanding of fluxes across the continental margins, to provide reliable boundary conditions for global models;
bullet_s an increased number of countries with an interest and skill in planning JGOFS-type activities and making the appropriate measurements and global-scale inferences.

More on JGOFS SCIENCE HIGHLIGHTS
(Highlights on the Marine Carbon Pump)

END OF THE FIELDWORK AND BEYOND

In 1998, as the fieldwork for most Process Studies were being completed, the JGOFS SSC at its annual meeting in Cape Town, confirmed its responsibility for integrating regional synthesis and modelling activities, for maintaining links to other ocean observing and global change programmes, and for leading the global synthesis and modelling phase. To help carry out its added tasks, the following SSCs were restructured from an observation to a modelling focus, the planning groups were transformed into regional synthesis groups, and the final phases of global synthesis and modelling were prepared. To facilitate the latter, the SSC met again later that year for a Synthesis Workshop in Southampton, and developed first, a plan for a global synthesis of JGOFS field observations, which also included the participation in IGBP-wide synthesis along with other core projects.
With this first phase well underway in 2000, SSC focused on the second one that comprised the JGOFS-wide synthesis and integration of regional syntheses products, and on the third phase that covered modelling of JGOFS datasets and the final archival of all datasets in the World Data Centres system. The current efforts built up an integrated and quantitative understanding of the biogeochemical fluxes of carbon in the ocean and their role in the global carbon cycle. The Final JGOFS Open Science Conference in Washington DC, USA, in May 2003 will provide a complete view of the most remarkable achievements of the project, along with a final synthesis, state-of-art book, before the JGOFS sunset date of December 2003.

 

More on JGOFS MILESTONES


More on JGOFS SCIENCE HIGHLIGHTS
(Highlights on the Marine Carbon Pump)

 

References

Brewer, P.G. 1986. What controls the variability of carbon dioxide in the surface ocean? A plea for complete information. In: Dynamic processes in the chemistry of the upper ocean (eds. J.D. Burton, P.G. Brewer, R. Chesselet), Plenum Press, New York, 215-281
GOFS, 1984. Global Ocean Flux Study. Proceedings of a workshop, Woods Hole Study Center, 10-14 September, 1984. National Academy Press, Washington, D.C.
SCOR, 1987. The Joint Global Ocean Flux Study - background, goals, organisation, and next steps. Report of the International Scientific Planning and Co-ordination Meeting for Global Ocean Flux Studies sponsored by the Scientific Committee on Oceanic Research held at ICSU headquarters, Paris, 17-19 February, 1987
SCOR, 1988. The Joint Global Ocean Flux Study. Report of the first session of the SCOR Committee for JGOFS. Rosenthiel School of Marine and Atmospheric Sciences, Miami, 25-28 January, 1988

 

      


Some presentations of the recent JGOFS Activities and Highlights are available hereafter:

Slide show on "Marine Data & Information Management – Lessons learnt from JGOFS" and a "companion text" presented during the "SCOR/IGBP Meeting on Data Management", December 2003.

Slide Show on "Marine Data Management: A positive evolution from JGOFS to OCEANS" presented during the EGU-AGU Joint Assembly, Nice, France, April 2003.

Slide Show on "JGOFS Data Management: What has been done? What has been learnt?" presented during the "Ocean Biogeochemistry and Ecosystems Analysis" International Open Science Conference, Paris, France, January 2003.

Slide Show on "JGOFS Data Management: What has been done? What has been learnt?" presented during the "Colour of Ocean Data" Symposium, Brussels, Belgium, Nov. 2002.

Slide Show on recent JGOFS DMTT activities and future plans presented by the JGOFS IPO and DMTT during the Modelling Workshop "Global Ocean Productivity and the Fluxes of Carbon and Nutrients: Combining Observations and Models", Ispra, Italy, June 2002.

Slide Show on JGOFS Science Highlights available after the two posters presented by the JGOFS IPO during the IGBP / WCRP / IHDP Conference "Global Change Open Science", Amsterdam, Netherlands, July 2001.

          


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