SINOPS
Silicon cycling in the world ocean:
the controls for opal preservation in the sediment as derived from observations and modelling

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Christoph Heinze, Ernst Maier-Reimer, Axel Hupe, Paul Treguer, Olivier Ragueneau, Nicolas Dittert, Aude Leynaert

Summary on the project flow

SINOPS was funded by the European Commission (MAS3-CT97-0141), started on May 1, 1998 and ended on September 30, 2001. A cost neutral extension period was granted from May 1, 2001 to September 30,2001. The project objectives were accomplished through the task structure as planned in the technical annex. SINOPS was a combined data analysis/modelling study on the global oceanic silicon (Si) cycle and was based on a close collaboration of observing and modelling scientists.

Objective 1. To provide a data collection of observations and a general circulation model which allow comprehensive studies on the Si cycling in the oceans.
Objective 2. To reproduce the first principles of silicon cycling in today's world ocean by use of an Ocean General Circulation Model (OGCM).
Objective 3. To offer an explanation for the present opaline sedimentary distribution.
Objective 4. To test our improved understanding of opal by a paleoceanographic application of the model and compare the simulations with the observed sediment record.

These objectives were achieved by applying the following methodology:

Method 1. Summarising (a maximum of all) existing observed Si and opal data in a data collection that allows systematically statistical and analytical evaluation.
Method 2. Providing a first coupled three-dimensional ocean-sediment model including opal on the basis of an OGCM velocity field that allows realistic regional resolution of large scale oceanic tracer fields.
Method 3. Utilisation of both tools to systematically diagnose model deficiencies and to remove disagreements between model and observations for the present ocean by development of new parametrizations of processes.
Method 4. Testing improved understanding by applying the model for a reproduction of major observational evidence from the Last Glacial Maximum and the Mid-Miocene.

Basic tasks (task 1 and 2) are carried out in parallel by the Max-Planck-Institut fuer Meteorologie/MPI and the Institut Universitaire Européen de la Mer/UMR CNRS 6539. The results of these tasks are then merged in task 3 and carried on in task 4 and 5.

Task 1: Data acquisition, compilation and archiving by means of PANGAEA (UMR CNRS 6539).
Task 2: Development of an OGCM reference run (MPI).
Task 3: Comparison of observations and model results (MPI, UMR CNRS 6539).
Task 4: Optimization of the model with respect to the observations (MPI, UMR CNRS 6539).
Task 5: Application of the model in simulating past ocean states (all partners).

The project was finished by a final workshop at IUEM, Brest, France under attendance of Dr. Catherine Eccles from the European Commission. The final report can be downloaded here (8.3 MB).

Publications

Scientific results and the procedures to achieve them are summarised in the Final Report. However, a number of peer-reviewed publications were produced:

  1. Dittert, N., Corrin, L., Diepenbroek, M., Grobe, H., Heinze, C., Ragueneau, O., 2001. Managing (pale-) oceanographic data sets using the PANGAEA information system: The SINOPS example. Computers & Geosciences accepted.
  2. Dittert, N., Diepenbroek, M., Grobe, H., 2001. Scientific data must be made available to all. Nature 414(6862), 393.
  3. Dittert, N., Heinze, C., 2002. Impact of paleo circulations on the silicon redistribution in the world ocean. Paleoceanography submitted.
  4. Dittert, N., Leynaert, A., Ragueneau, O., Heinze, C., 2001. Hunting and gathering silicon data to tackle climate forecasting. EOS Transactions, American Geophysical Union 82(9), 113-117.
  5. Gehlen, M., Heinze, C., Maier-Reimer, E., Measures, C.I., 2002. Coupled Al-Si geochemistry in an ocean general circulation model: A tool for the validation of oceanic dust deposition? Global Biogeochemical Cycles submitted.
  6. Heinze, C., 2001. Towards the time dependent modeling of sediment core data on a global basis. Geophysical Research Letters 28(22), 4211-4214.
  7. Heinze, C., 2002. Assessing the importance of the Southern Ocean for natural atmospheric pCO2 variations with a global biogeochemical general circulation model. Deep-Sea Research Part I : Oceanographic Research Papers in revision.
  8. Heinze, C., Hupe, A., Maier-Reimer, E., Dittert, N., Ragueneau, O., 2002. Sensitivity of the marine "biospheric" Si cycle for biogeochemical parameter variations. Part I. Control run and observations. Global Biogeochemical Cycles submitted.
  9. Heinze, C., Hupe, A., Maier-Reimer, E., Dittert, N., Ragueneau, O., 2002. Sensitivity of the marine "biospheric" Si cycle for biogeochemical parameter variations. Part II. Parameter variations and optimisation. Global Biogeochemical Cycles submitted.
  10. Ragueneau, O., Dittert, N., Pondaven, P., Tréguer, P., Corrin, L., 2002. Si/C decoupling in the world ocean: is the Southern Ocean different? Deep-Sea Research Part II: Topical Studies in Oceanography accepted.
  11. Ragueneau, O. et al., 2000. A review of the Si cycle in the modern ocean : recent progress and missing gaps in the application of biogenic opal as a paleoproductivity proxy. Global and Planetary Change 26, 317-365.
  12. Tréguer, P., Legendre, L., Rivkin, R.T., Ragueneau, O., Dittert, N., 2002. Water column biogeochemistry below the photic zone. In: Fasham, M.J.R., John, F., Platt, T., Zeitschel, B. (Eds), Ocean Biogeochemistry. Springer-Verlag, Heidelberg Berlin, pp.submitted.