Large-scale data analysis and numerical simulation for the north-west European shelf (NOWESP)

From a state-of-the-art of present-day knowledge of the North-west European Shelf it is shown that due to the large scale and the strong variability of the phenomena involved, our knowledge still has a fragmentary character. No insight exists in the longterm evolution of the shelf system and no reliable estimates are available regarding the net retention or release of organic matter and other constituents. NOWESP (North West European Shelf programme) aims to make an assessment of the fluxes of energy and matter, as well as their variability, on the basis of existing field and model data. Because the North-West European Shelf, and especially the North Sea, is an intensively investigated area and possesses a large number of monitoring networks, comprehensive hydrographic and chemical-biological data sets are available in the NOWESP countries. These have been made available for the purposes of NOWESP. Some first results of the data analysis are demonstrated. Accurate modelling of the transport of particulate matter in general, and of organic carbon, in particular, on the continental shelf asks for models with a high resolution in specific regions (cf. coastal zones, frontal areas, etc.). This is not possible with the present-day models. Therefore the possibilities of recent hardware developments are being reviewed for a new generation shelf flux model, giving special attention to the required mathematical algorithms for local grid refinement and numerical approximation techniques that can be implemented efficiently on vector and parallel processors. It is demonstrated how parallel processing techniques can be used to achieve a significant increase in useful computer power for meeting the present-day and forthcoming problems in large marine ecosystems. In 1995 a concerted action was starred, called MMARIE (''Application of High Performance Computing Techniques for the Modelling of Marine Ecosystems''), in which experience is shared and information and codes are exchanged between the partners.