Publication Abstract

Linking Biogeochemical and Upper Trophic Level Models using an Xml based Semantic Coupler

Beecham J.A.*, Bruggeman, J., Aldridge, J.N., Mackinson, S.

When we wish to couple computer models together we have to describe both how the physical connections between the models (file formats, network protocols and the like) and semantic information about what the data means (grid type and dimensions, names of organisms and variables and the units in which numerical quantities are expressed). In some cases there are incompatibilities but mechanisms exist to convert between different representations, for exampling converting units of wet mass per unit volume into molar units of chlorophyll or carbon. Couplerlib is a library for doing this where the semantic information is stored as a dictionary of xml definitions for unit conversions and names and hierarchies of functional groups. We have linked two models; one is the biogeochemical model BFM, embedded in the physical model GOTM (General Ocean Turbulence Model), and the other is the Ecosim ecological model. The xml dictionary expresses the semantic relations between the entities in the two models and a second xml file specifies which groups are linked (in this case Phytoplankton and Zooplankton). When the two models are linked and exchange information on a daily basis, the plankton dynamics predicted by the GOTM-BFM model feed through to the dynamics of the groups in Ecosim that feed on them and the predation effects can be seen in GOTM-BFM. Currently this model linking approach is being extended to 3D models running across networks of computers.

Reference:

J.A. Beecham*, Bruggeman, J., Aldridge, J.N.*, Mackinson,S.P* (2010) Linking Biogeochemical and Upper Trophic Level Models using an Xml based Semantic Coupler. ICES CM 2010/ Session L