Wave Climate and the Effect of Induced Currents over the Barrier Reef of the Cays of Alburquerque Island, Colombia

Abstract

The Alburquerque Cay Islands belong to a group of western Caribbean atolls, with a barrier reef of coral that is more than 8 km in diameter. An understanding of the reef ocean dynamics and its direct relationship to the functioning of the ecosystem is important since the significant energies that are involved should play a fundamental role in the coral and fish distributions in the coral reef, which are fundamental for its sustainability. The microtidal regime and the predominance of the trade winds produces coastal circulation, which is induced by waves breaking against the barrier. The study of the water dynamics that are described in this paper was carried out by using a stationary model that is based on the shallow-water equations theory, with consideration to the radiation stress gradients in the waves, whose patterns were evaluated with the pseudo-data of a reanalysis of a virtual buoy in front of the atoll and were propagated in the domain of interest by using the simulating waves nearshore (SWAN) spectral model. The results demonstrate the bi-modal behavior of the currents of water jets, with the occurrence of extreme waves with velocities greater than 1 m/s along the barrier. For the mean wave regime, circulation occurred around the coral mounds. This circulation suggests that the reef, the orientation of which coincides with the direction of the predominant waves, was formed under these average conditions. The wave climate is primordial to the reef environment, and climate change may affect the coral health.