The aim of the North Sea Community Project is to develop a water quality model of the North Sea Within this broad aim three more specific objectives have been identified the development of a three dimensional transport model, the better understanding and quantification of non-conservative processes, and the definition of a seasonal cycle. The project is interdisciplinary, covering physical, chemical, biological and sedimentological processes and their interactions, and will act as a focus for UK shelf seas oceanography. This paper describes the scientific background to the project and outlines its implementation.
The continental shelf seas around the British Isles have a major impact on life in the UK and on the Continent. The seas are a resource, not just for hydrocarbons and fish, but also for aggregates and renewable energy, are important for commerce through shipping and for communications through tunnels and seabed telephone cables, are a potential threat through coastal erosion and flooding and to coastal and offshore structures, are a receptacle for natural and man-made wastes, including heat from power stations; affect our climate, both locally, mellowing the extremes of winter and summer, and globally, transporting heat and as a source for water, and finally provide extensive recreational amenities. For the well-being of all it is vital that these activities, separately and as a whole, do not stress the environmental health of the North Sea Although potential threats are associated with all these activities two wide scale threats are posed by contaminants and eutrophication- the depletion of dissolved oxygen caused by the decay of unusual plankton blooms encouraged by high levels of nutrients, of which one source is the increasing application of fertilizers for agriculture.
Accordingly the goal of this study is to develop a water quality model in order to provide the accurate quantitative assessments and long term predictions necessary for a rational management strategy for the North Sea Such a model will be complex since it will involve inter-related physical, chemical, biological and sedimentological process. However, the foundations already exist since the dominant physical processes of waves, tides and surges which underpin the others are mainly understood. The distributions of the chemical, biological and sedimentological parameters are largely known, the relevant processes have been identified, and quantification of their rates is beginning to be estimated.
A prerequisite to achieving this goal is the development of a water transport model able to predict the horizontal and vertical variations of currents in the North Sea as well as the evolving density field. This is a logical extension to the present tried and tested two-dimensional tide and surge models and to experimental three-dimensional models. Progress has been made in this direction (ref 1). The objective is feasible given that powerful computers, such as the CRAY XMP at Rutherford, are available in the UK Such a model can be applied immediately to predicting the movement and distribution of quasi-conservative tracers, such as salinity or caesium 137.