Flushing time of solutes and pollutants in the central Great Barrier Reef lagoon, Australia
Yonghong Wang A B E , Peter V. Ridd B , Mal L. Heron B , Thomas C. Stieglitz B C and Alan R. Orpin B DA College of Marine Geoscience, Ocean University of China, Qingdao 266003, China.
B School of Mathematics, Physics and Information Technology, James Cook University, Townsville, Qld 4811, Australia.
C Australian Institute of Marine Science, PMB 3, MC, Townsville, Qld 4810, Australia.
D NIWA, Private Bag 14-901, Kilbirnie, Wellington, New Zealand.
E Corresponding author. Email: yonghong.wang@jcu.edu.au
Marine and Freshwater Research 58(8) 778-791 https://doi.org/10.1071/MF06148
Submitted: 16 August 2006 Accepted: 30 July 2007 Published: 27 August 2007
Abstract
The flushing time of the central Great Barrier Reef lagoon was determined by using salinity as a tracer and developing both an exchange model and a diffusion model of the shelf exchange processes. Modelling suggests that the cross-shelf diffusion coefficient is approximately constant for the outer half of the lagoon but decays rapidly closer to the coast. The typical outer-shelf diffusion coefficient is ~1400 m2 s–1, dropping to less than 100 m2 s–1 close to the coast. Flushing times are around 40 days for water close to the coast and 14 days for water in the offshore reef matrix.
Additional keywords: diffusion coefficient, exchange and diffusion model.
Acknowledgements
This study was supported by the Australian Research Council Discovery Grant DP0558516. Financial support was also given by National Natural Science Foundation of China grant 40406015. Martial Depczynski, Chris Fulton, and James Whinney helped with the collection of the salinity data. Severine Thomas and three anonymous reviewers greatly helped improve this manuscript.
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