INTRODUCTION
PROGRAM SCOPE
    Current Synthesis and Modeling Projects
    Future Directions
SMP STRUCTURE
    Working Groups
    Overall SMP Structure
SMP ACTIVITIES
    Annual PI Meetings and Workshops
    Core Biogeochemistry-Ecosystem Model
    SMP Model-data Management
    Communication and Outreach
GRAND SYNTHESIS AND THE JGOFS LEGACY
    Individual Science versus Community Activities
REFERENCES
 

INTRODUCTION

The Joint Global Ocean Flux Study (JGOFS) is an international scientific program devoted to the study of the ocean biogeochemistry of carbon and related elements and the linkages of the ocean with the global carbon cycle. The U.S. JGOFS program has recently completed a decade long, intensive field effort that includes: two on-going time-series stations off Hawaii and Bermuda; a series of process studies in the North Atlantic, Equatorial Pacific, Arabian Sea, and Southern Ocean; and a Global Ocean CO₂ Survey in conjunction with the World Ocean Circulation Experiment (WOCE).  The resulting ocean biogeochemical data sets (available on the web http://usjgofs.whoi.edu/), together with satellite ocean color data from the recently launched NASA Sea-viewing Wide Field-of-view Sensor (SeaWiFS), form a unique, long-term resource for the ocean community.  With the completion of the field phase, the U.S. JGOFS has initiated a final Synthesis and Modeling Project (SMP), which will build on and integrate these data sets in order to address the key scientific themes of JGOFS:

• determine the processes controlling the oceanic carbon cycle and ocean-atmosphere carbon fluxes
• develop improved capabilities for predicting future changes.

Specifically, the central objective of the SMP is to synthesize knowledge gained from U.S. JGOFS and related studies into a set of models that reflect our current understanding of the ocean carbon cycle and its associated uncertainties (U.S. JGOFS, 1997).  The SMP has been tasked to address not only the processes that control carbon partitioning among oceanic reservoirs, but also the implications for ocean/atmosphere carbon exchange. Both data synthesis and modeling proposals have been encouraged with an emphasis on coordinated interaction between the two.  The major elements of the program include:

• Individual PI level projects
• Topical Working Groups (eight at present)
• Project management team (two co-coordinators and a project scientist)
• Data management (both distributed and centralized)
• Community activities (PI meetings, mini-workshops, special issues etc.).

The SMP became a full fledged program with the funding of the first SMP awards in early 1998, and at present, the SMP consists of 41 separate grants and 91 investigators.  Funding for these grants is from the National Science Foundation (NSF), the National Aeronautical and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and Department of Energy (DOE) (Table 1).

PROGRAM SCOPE

Specific projects within the SMP fall into two broad categories: data synthesis and extrapolation, and modeling. There is considerable (and necessary) overlap between the two, and the overview of the projects provided below is certainly a simplification of the collective efforts of the individual researchers (details on individual SMP grants can be found at http://usjgofs.whoi.edu/mzweb/syn-mod.htm).  The current scope and balance of the program are displayed in two cross-cut diagrams (Figure 1, Figure 2), one based on geographic region of study and the other on biogeochemical processes.

Current Synthesis and Modeling Projects

At the local to regional scale, a series of data synthesis and food web modeling investigations are exploring aspects of euphotic zone production, recycling, export, transport and remineralization, and sediment cycling using the JGOFS process and time-series data base and related data sets. Individual projects are concentrating, for example, on subsets of the overall JGOFS data (e.g. bacteria, mesozooplankton, HPLC pigments).  Related projects focus on the distribution and dynamics of planktonic functional groups (e.g. N₂ fixers, diatoms, calcifiers).  The eventual aim of many of these food web related studies is to extrapolate the findings to basin and global scale and/or to develop improved process-based parameterizations that can be incorporated into regional and global models.

One or more regional ecosystem modeling studies are underway for each of the following U.S. process/time-series study locations: Equatorial Pacific and Atlantic, Arabian Sea, Ross Sea, Bermuda, and North Atlantic.  There are also four projects which are concentrating on data synthesis and/or modeling for various continental margins: NW Atlantic margin, southern Caribbean, Cariaco Basin, and several coastal upwelling regions.  The regional synthesis and modeling studies as well as some of the food web projects rely heavily on satellite data. Some ten projects utilize satellite data, in particular SeaWiFS ocean color, as an
integral part of both model evaluation and time/space extrapolation.

On the global perspective, over a dozen synthesis groups are working on the JGOFS/WOCE global CO₂ survey data with good coverage for all of the carbon related parameters (DIC, alkalinity, ¹³C, ¹⁴C, nutrients, oxygen, pCO₂, etc.).  A coordinated global biogeochemical modeling effort is also underway as part of the international Ocean Carbon Model Intercomparison Project (OCMIP, http://www.ipsl.jussieu.fr/OCMIP/).  As the name implies, this is an observation-based evaluation of some thirteen global ocean biogeochemical models of the natural and anthropogenic inorganic carbon system, biogeochemical fields (nutrients, oxygen), and related passive chemical tracers (e.g. CFCs, ¹⁴C, ³He).

Future Directions

The U.S. JGOFS SMP is expected to continue through the 2003-2004 time frame, and a third round of proposals submitted for funding beginning in FY 2000 is currently under review.  As the program matures and specific initial projects are completed, the foci for the program will be refined to emphasize both emerging new scientific directions and remaining unfinished elements of the original implementation plan.  The SMP together with the U.S. JGOFS Steering Committee recently assessed the program with the question of future priorities in mind.  The following topics, of equal importance, were identified as filling critical gaps for SMP science:

1. synthesis of primary production, new production and export production (both particulate and dissolved)
2. the mechanisms and rates of mid to deep water particle flux and remineralization as well as sediment diagenesis
3. controls and distributions of calcium carbonate and silica production, transport and remineralization
4. biogeochemical effects of trace metal cycling
5. spatial and temporal extrapolation of biogeochemical flux estimates (e.g. export production) from local to basin and global scales
6. development, evaluation and incorporation of mechanistically based, biological models for global carbon cycle simulations
7. synthesis and modeling studies of the Arabian Sea, Southern Ocean, North Atlantic, ocean margins (with respect to the role of each in basin to global-scale carbon cycle), and the set of U.S. and international time-series stations data.

SMP STRUCTURE

Working Groups

Working groups are a key element in the SMP strategy to promote collaboration and the overall synthesis of JGOFS results.  The working groups were formed at the 1998 PI meeting in Boulder, CO, and the 1999 PI meeting agenda at Keystone was centered around breakout sessions for the working groups.  The working group structure is designed to tackle a number of critical tasks of general benefit to the scientific community, but which are larger in scope and/or require more resources than would be typical for a single SMP grant.

Some of the working groups (e.g. N₂ Fixation) are focused on a specific scientific issue while others (e.g. Large-Scale Data Sets) involve significant technical as well as scientific effort.  At the Keystone meeting, SMP investigators examined the current structure with a critical eye toward combining, splitting, or creating new working groups.  In the end, the original seven working groups were maintained, and a new one, a "Food Web" group, was created based on the need to better understand and model the role of various food webs in biogeochemical processes.

These eight SMP working groups addressed four major issues at the Keystone meeting:

1. to define both the scientific and technical objectives of the group;
2. to identify major hurdles to achieving these goals;
3. to develop a plan for coordination across individual projects;
4. to enlist individuals with specific tasks toward achieving the plan.

Several working groups suggested writing a synthesis paper as an appropriate focal point, enabling the investigators to review in detail the current status and future directions for their topic.  For example, the Satellite Biogeochemistry working group suggested a "reverse engineering" approach; that is develop regional empirical relationships, which can then be extrapolated in space and time, between the current suite of remotely sensed data products (e.g. ocean color, SST, winds, altimetry) and key observed biogeochemical processes (e.g. primary and export production; functional group distributions etc.).  The synthesis paper would also include a section with suggestions toward future sensor development.

Overall SMP Structure

Figure 3 illustrates schematically the relationships among the JGOFS field data and the various SMP projects and working groups.  The common modeling tools currently utilized within the SMP community are illustrated by the bottom row of blue boxes: global 3-D biogeochemical models (an example being the OCMIP-2 biotic model), box and conceptual models, 1-D biological-physical models, and regional 3-D models (e.g. for the Equatorial Pacific, Arabian Sea, Ross Sea, specific continental margin sites).  The top row of green boxes shows some of the primary potential products from the SMP: a set of improved regional and global coupled ecosystem-biogeochemical models and the original and synthetic data sets required for model evaluation.

Through the working group structure, SMP investigators have identified a number of parallel paths to reach these objectives. All of these paths are based on the JGOFS field data and existing models:

• synthesize global survey, satellite, time-series and process study data
• develop intermediate complexity global biogeochemistry models (see below)
• create common 1-D regional physical test-beds for evaluating biogeochemical models
• explore and improve regional models and their connections to global-scale models
• analyze food web structures from the process studies and build new, mechanistic food web models
• generate and evaluate sub-models for geochemically relevant planktonic functional groups

SMP ACTIVITIES

Annual PI Meetings and Workshops

The PI-level grants and projects discussed above form the foundation of the SMP, but to be truly successful in synthesizing the wealth of JGOFS data, the program also requires extensive collaborations across individual projects.  Four main avenues are being pursued to stimulate these interactions: the annual summer workshops and PI meetings, topical mini-scientific workshops, formal working groups, and program-wide community activities.

A SMP summer workshop series was initiated during the spin-up phase of the project to explore specific scientific themes.  The two open workshops on Ocean Biogeochemical Time-series (1997) (Doney and Sarmiento, 1998) and Ocean Biogeochemical Response to Climate Change (1998) (Doney, 1998; Doney et al., 1999 ; http://usjgofs.whoi.edu/mzweb/smp/mtgover.htm and http://usjgofs.whoi.edu/mzweb/smp/smp98.htm) successfully engaged a wide community of scientists in discussions on current key issues and future directions for field.

The 1999 summer workshop was transformed into an annual SMP PI meeting to accommodate the growing size of the project. The main goals of the meeting held this past July at Keystone, Colorado were to:

• exchange SMP scientific results
• promote collaborative interactions
• catalyze the SMP working groups
• and coordinate community activities.

The SMP also hosts a series of topical mini-workshops which focus on specific scientific questions relevant to the overall SMP goals. The mini-workshop format allows in-depth examination of critical problems by experts from both inside the SMP and from the broader community. These meetings have defined goals: to address the key questions and to formulate solution strategies using a combination of data synthesis and modeling.  In some cases new targeted field studies are identified. Although field studies will not be part of the SMP, this guidance provides the strong  framework for future observational needs, and will be an important legacy of the program. A particular emphasis of many of these mini-workshops is to develop improved, mechanism based algorithms for incorporating biogeochemical processes into numerical models. The first mini-workshop on Functional Groups was held held in January, 1999 (http://usjgofs.whoi.edu/mzweb/falko_rpt.html), and two more on N₂ Fixation and Equatorial Pacific Modeling were recently held in the Fall of 1999.

Core Biogeochemistry-Ecosystem Model

The concept of encapsulating the findings of JGOFS in the form of numerical models has been a stated goal from the inception of the overall program. One proposed element as part of the "grand synthesis" of SMP would be a "core biogeochemical model" implemented globally in a 3-D circulation model. Rather than promoting a single model that could address all scientific questions (such a model is a fictional chimera at best), the SMP could develop a base-line global biogeochemical model of manageable complexity and computational demands that incorporates the emerging new understanding from JGOFS and the SMP. The model would move beyond the current generation of very simple biogeochemical models (as exhibited by the OCMIP-2 biotic model) by incorporating multiple nutrient limitation (N, P, Fe) and major geochemically relevant processes for carbon (N, CaCO₃, and silica cycling).  A hierarchical approach is envisioned, and a schematic developed by the Biogeochemical Modeling working group is shown in Figure 4.

SMP Model-data Management

The success of the SMP depends critically on the open availability and exchange of data, model codes and solutions, and synthetic data products.  From its inception, U.S. JGOFS field programs have acknowledged the importance and net benefit of open and timely data exchange, and a similarly spirited model-data policy has been adopted for the SMP (http://usjgofs.whoi.edu/mzweb/model_data_revised.html).  The main elements of the policy are the requirements that SMP PIs make their results (code, solutions, synthetic data products, meta data) available to other SMP PIs and eventually to the public via a SMP model-data archive. The U.S. JGOFS field data are distributed through the web-based JGOFS data system (or linked sites) maintained by the Woods Hole Data Management Office (DMO). The exact needs of the SMP differ from those of the field programs in some regards, and the SMP and the DMO are currently developing an SMP data management effort whose goals are to:

• implement the SMP model-data policy
• provide SMP investigators with access to key data sets for their research
• promote cross-project collaboration within the SMP
• ensure timely, public access to the SMP results
• address the permanent archival of some elements of the SMP results

The outstanding data management questions include:

1. data distribution - whether to provide a centralized (e.g. at the U.S. JGOFS Data Management Office in Woods Hole) or distributed local system;
2. data format - standardization of data formats and processing levels;
3. meta-data standardization; and
4. data volume (particularly for large model simulations).

One suggestion toward reducing the data volume from global models is to extract a data subset along the individual WOCE/JGOFS global CO₂ Survey sections.  Two examples of existing interactive data management systems under investigation are DODS (Distributed Ocean Data System from URI, a progeny of the original JGOFS database system, http://www.unidata.ucar.edu/packages/dods/) and the NOAA/PMEL Ferret-based data web server (http://ferret.wrc.noaa.gov/fbin/climate_server).  The SMP plans to have a pilot system in place before next summer's PI meeting.

The Community Synthesis and Modeling Group is compiling a selection of U.S. OCMIP results, which will include monthly mean 3-D physics (velocities, temperature, salinity, mixing coefficients, etc...) for one annual cycle at steady state; and subsets of tracer and carbon cycle experiments from the equilibrium abiotic and biotic carbon simulations and the transient radiocarbon, anthropogenic CO₂, and chlorofluorocarbon simulations.  The international OCMIP analysis group has already developed a set of packaging standards and tools, and the release of the U.S. OCMIP results will be a good first test for the SMP data management effort.

Communication and Outreach

The SMP is continually searching for new and innovative vehicles for communicating project results internally within the program, with the broad scientific community and with the public.  The SMP web page (http://usjgofs.whoi.edu/mzweb/syn-mod.htm) has recently been scaled up to provide more project information, progress updates, and links to individual SMP projects.  A preprint/reprint site for SMP results has been also been implemented. As the web becomes an increasing resource for schools, colleges and individuals, future plans for the SMP web site include targeting the general audience with overview material that outlines the main science issues and achievements of U.S. JGOFS.  The idea of a "SMP Picture Gallery" has also been raised.

Along more traditional lines, a SMP journal special issue in Deep-Sea Research II has been announced with a submission deadline of April, 2000 (guest editors S. Doney and J. Sarmiento).  Another special issue is slated to follow one to one and a half years later.  The SMP would also benefit from an overview article describing the achievements of U.S. JGOFS in redefining our understanding and quantification of the ocean carbon cycle; such an article in a high profile journal (e.g. Science or Nature) would reach beyond the typical JGOFS community targeted by the DSR special issue series.  The Community Modeling and Synthesis working group is assisting with many of these issues.

GRAND SYNTHESIS AND THE JGOFS LEGACY

As the SMP nears its mid-point, some discussion has begun regarding the ultimate legacies of U.S. JGOFS, and of the SMP in particular. One way of posing the dialogue is whether or not the SMP should be looking to produce a "grand synthesis", some unifying framework for the overall knowledge gained by JGOFS on the marine carbon cycle which could be up to and including the development of community ocean biogeochemical models.  The Community Modeling and Synthesis group created the schematic shown in Figure 5 to depict the flow of information and products from the SMP to:

1. the scientific community (including JGOFS),
2. funding and political agencies,
3. the general public.

The second element will be the research papers and review articles in the scientific literature.  Again, the SMP can follow the excellent path already defined by the process and time-series studies by using special issues and "commissioned" review articles.  The International JGOFS program has also undertaken the compilation of
a book synthesizing the ocean carbon cycle, with individually authored chapters covering the major themes of JGOFS.

A third facet is to develop a consensus statement of the major advances in the ocean carbon cycle science (based on the JGOFS era research), the remaining major uncertainties, and the critical future research directions.  This statement should then be conveyed to funding agencies and program managers (NSF, NASA, NOAA, DOE...), and also to policy makers through such avenues as the IPCC process, umbrella scientific organizations (AGU, ASLO, CORE), and infant and future scientific programs (e.g. SOLAS, Carbon and Climate, OCTET).  To a degree this is already occurring informally, but the SMP should work with the U.S. JGOFS Steering Committee to draft a more comprehensive document.

A fourth synthesis aspect mentioned above is communication and outreach to the general public, in particular students and educators at the K-12 and undergraduate levels.  Web-based, interactive approaches should be pursued strongly.  The SMP should also encourage, or generate if need be, popular press articles about the science of biogeochemistry and the role of the ocean in the large Earth System.

A potential fifth legacy of U.S. JGOFS would be a ``community ocean  biogeochemical model''.  Based on discussions at the Keystone PI meeting, there is not yet a consensus among the SMP investigators whether such a model is a desirable goal and whether the target audience would be more the scientific or policy making communities (i.e. CME-type science  community resource versus a IPCC-type policy makers tool).  This should be a continuing topic of discussion within the SMP.

Individual Science versus Community Activities

A major challenge for the SMP is how to complete the worthwhile yet ambitious community activities outlined above (e.g. working group tasks; SMP data management system; web-based public outreach).  All of the SMP investigators were funded based on the excellence and importance of their individual science proposals, and their first responsibility is (and should be) the completion of their research.  The significant  progress within the SMP Working Groups has so far relied on SMP members volunteering their time and resources because they view those activities as both personally and mutually beneficial.  Certainly the bulk of the SMP community activities can and will continue in a similar vein.  However it is not clear how more involved tasks -- developing an effective data management system that can deal with the volume and diversity of the SMP model data, creating an interactive regional test-bed system (data sets, code, optimization and analysis tools), or constructing and evaluating a next generation community biogeochemical model -- will succeed without a significant increase in community resources.

The SMP management grant currently supports one project scientist, Dr. Joanie Kleypas, who works at NCAR on coordinating the SMP infrastructure:  meetings and workshops, journal special issues, the SMP web-page, and the developing data management systems.  Two main options are open to accommodate the growing demands of the data management effort and more science-directed community projects: expand the scope and resources of the SMP management group and Woods Hole Data Management Office; encourage targeted SMP proposals on specific community science projects.  Likely a mix of the two will be required, and the SMP management group is actively discussing these issues with the U.S. JGOFS Steering Committee.

REFERENCES

Doney, S.C., 1998: SMP Workshop looks at ocean biogeochemical responses to climate change, U.S. JGOFS News, Vol. 9, No. 3, 2.

Doney, S.C. and J.L. Sarmiento, 1998: Synthesis and Modeling Project; Time-Series Stations and Modeling Planning Report. U.S. JGOFS Planning Report Number 21, U.S. JGOFS Planning Office, Woods Hole, MA, 96 pp.

Doney, S.C., J.L. Sarmiento, and R.M. DeConto, 1999: The Response of Ocean Biology and Biogeochemistry to Climate Change, U.S. JGOFS Synthesis and Modeling Project, Planning Workshop Report, U.S. JGOFS Planning Report Number 22, U.S. JGOFS Planning Office, Woods Hole, MA, pp. 1-11.

U.S. JGOFS, 1997: Synthesis and Modeling Project Implementation Plan, J.L. Sarmiento and R.A. Armstrong, U.S. JGOFS Planning Office, Woods Hole MA, 73 pp.
 
 

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