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.
More on JGOFS MILESTONES
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:
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
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:
an assessment of large-scale carbon fluxes, obtained from a
greatly increased network of observations;
JGOFS SCIENCE HIGHLIGHTS
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.
More on JGOFS MILESTONES
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
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
text" presented during the "SCOR/IGBP Meeting on Data
Management", December 2003.
on "Marine Data Management: A positive evolution from JGOFS to OCEANS" presented during the
EGU-AGU Joint Assembly, Nice, France, April 2003.
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.
on "JGOFS Data Management: What has been done? What has been
learnt?" presented during the "Colour of Ocean Data"
Symposium, Brussels, Belgium, Nov. 2002.
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.