Hydrodynamics at the whole of Great Barrier Reef scale (MTSRF Project 2.5i.1)

A three-dimensional whole-of-GBR baroclinic hydrodynamic model was applied at a spatial resolution of between 1 and 4 km. The model simulations are compiled to examine the intensity, duration and frequency of different lower salinity events. Return periods are then calculated from the annual frequency of such events.The model includes the factors affecting currents, mixing, temperature and salinity within the GBR lagoon and exchanges with the adjacent Coral Sea: river discharge, time-series wind, tidal.Accurate boundary forcing for offshore ocean boundaries was provided by a global, data-assimilating, eddy-resolving model. To allow future development of other essential aspects of a large-scale water quality model for the GBR, particularly sediment dynamics and biogeochemical components. To test this model and strengthen the likelihood of future predictions, a hindcast was made of circulation within the GBR lagoon during the 2009 wet season, including prediction of the trajectories and spatial distribution of major freshwater inflows during this period.