Impact of cross-reef fluxes on the Ouano lagoon circulation.
Résumé
In meso-tidal lagoons the coral reef barrier can be temporarily covered by water at high tide and emerged at low tide, inducing particular cross-reef dynamics. In order to understand the importance of crossreef fluxes on lagoon dynamics a field survey had been conducted on Ouano Lagoon (New Caledonia). The lagoon water dynamics were analyzed and compared to a numerical model output. The main current was found to be northward during the flood, with inward flows through the ocean passes and through the south passage and outward flows through the north passage. During the ebb, currents are usually reversed. Concerning tidally averaged fluxes, they are mainly inward at the ocean passes and southward in passages. Finally, numerical tests were performed to evaluate the impact of cross-reef fluxes on this circulation. The results of this study are, then, discussed.