The objective of Coherens is the dissemination and exploitation of an integrated three-dimensional model wich couples the physics, microbiology and sedimentology of coastal and shelf seas. The model has been developed over the period 1990-1996 within two MAST-supported projects by a multinational European group, and used to simulate conditions in stratified coastal areas with an important river input and in the North Sea. The model will be made available to The scientific and coastal management communities for further diagnostic use and for testing as a prognostic and management tool.
The specific objectives are :
a)To write a detailed manual with the model's description and a user guide. b)To run a series of test cases to evaluate model performance. c)To create a graphical interface for user output.
d)To validate the model against the available data of the 1988-1989 UK Natural Environment Research Council's North Sea Project.
e)To establish the scientific content of the model by publications in the scientific literature.
f)To produce a CD-ROM with the source code and visualised model results. g)To set up a communication channel for user support and information about further updates of the model.
The program has four major components : i) a physical part with a general module for solving advection-diffusion type equations; ii) a biological module describing the cycling of carbon and nitrogen through microplankton and detrital compartments, with corresponding changes in nitrate, ammonium and oxygen concentrations; iii) a sediment module describing the deposition and erosion of suspended organic and inorganic material through a "fluff" layer; iv) an Eulerian and a Lagrangian transport module for contaminants. The modular design allows easy updating of any particular process, the inclusion of an alternative solution method or the addition of new processes. A series of switches is implemented allowing the user to select whichever processes are required.
A long-term simulation with realistic forcing is planned in the Southern Bight and the central part of the North Sea for the period of March to October 1989. The time period covers a seasonal cycle with important phenomena such as the spring bloom, thermocline formation and erosion, thermal and saline fronts. The model results will be compared with the physical and biological data collected at nearly forty stations throughout the area during the North Sea Project.
keywords : integrated numerical modelling; physics; biology; sediments; contaminants; shelf seas.
Funding SchemeCSC - Cost-sharing contracts
CH43 7RA Prenton
L43 7RA Birkenhead
EH10 5DT Edinburgh