MODELING THE OCEANOGRAPHY OF THE GREAT BARRIER REEF

Date:

Tuesday 1 April 2008

Time:

12:00 – 1:00pm

Location:

CairnsA21.002, Townsville- DA009-002

Presenter:

DrJonathan Lambrechts,Catholic University of Louvain, Belgium

Abstract:

An 1-million grid point, unstructured-mesh, finite element, depth-integrated model of the hydrodynamics of the whole Great Barrier Barrier Reef (GBR) has been developed and implemented on a parallel computer system at JCU. Far away from reefs, islands and important bathymetric features, the mesh size may be as large as a few kilometres, whereas, in the vicinity of reefs and islands, the grid is drastically refined, leading to meshes that can be 100 metres in size. This enables our model to simulate motions characterized by a wide range of space and time scales. Large scale currents, i.e. the tides, the wind-induced circulation and the bifurcation of the East Australian Current, are reproduced with an accuracy that is comparable to that achieved by today's large-scale models of the GBR. The model is also successful at representing small-scale processes, such as tidal jets, their instabilities, as well as the eddies developing in the wake of islands, reefs, and headlands. The influence of the small scales on the large scales will be investigated. In the immediate future the model will be used for studying the connectivity between reefs and subdomains of the GBR, a key input for the HOME ecohydrology model of the GBR, and predicting jellyfish risk maps. Once validated, we plan to couple an ecological module for the water column with the present hydrodynamic code.

Contact:

Jonathan Lambrechts is at JCU for the next 2 weeks. He will implement the SLIM model of the GBR on JCU parallel computing system. I attach his newest paper in press on that topic.