The main objective of ecosystem modelling studies within the Marine Climate Change Programme is to establish modelling capacity to forecast the ecosystem response in the Irish marine environment to climate change. Together with physical downscaling modelling, the coupled ecosystem models will complement the climate data analysis while also using data products to tune model performance.
Within the scope of the project, the approach to ecosystem modelling is to implement a suite of three-dimensional, coupled ocean-ecosystem models with various spatial coverage and resolution. Ecosystem model complexity for each application will depend on the biomass dynamics and processes of interest for the region of application.
As an initial product, a mesoscale resolution, large-scale ocean-ecosystem model of the Northeast Atlantic is being developed. The model is designed to include various options for ecosystem dynamics and will provide hindcasts of the Irish marine ecosystem state, which will be validated using the environmental data available to the Marine Climate Change program.
Diagram of a typical marine ecosystem model showing the simulated biomass compartments (boxes) and rates (arrows) in terms of the concentration of nitrogen. In red are recent extensions of the model to incorporate multiple nutrient limitation, size structures and planktonic functional groups (Moore et al., 2001).
This model, in the long run, will also provide ecosystem boundary conditions for the high-resolution, nested regional models that will be further downscaled from the mesoscale model later in the programme (Clew Bay, Rockall Trough/Porcupine Bank regional models as possible candidates).
Potential products of the ecosystem models will be:
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Primary productivity time series – verified hindcast and decadal forecast in response to climate scenarios
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Deep nutrient distribution as affected by large-scale circulation
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Zooplankton dynamics: potential input for higher trophic level (fisheries/bioenergetics) modelling
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Competition and shifts among species and functional groups in response to climate change