Abstract
This article presents a methodology for simulating the Algarve coastal circulation using realistic forcing (e.g. low-frequency circulation, tide, high-resolution atmospheric forcing). Low-frequency open boundary conditions are defined via a downscaling of the HYCOM-US operational solution for the Gulf of Cadiz. Atmospheric forcing is imposed using the MM5 high-resolution mesoscale model (9 km resolution near the coast). A 3-level nesting system based on the MOHID numerical system is implemented. The higher nesting level has a horizontal resolution of 0.02° along the Algarve coast. The methodology is first validated qualitatively. A comparison between the numerical results and the conceptual model of the circulation described in the literature is presented. A quantitative validation is also performed, based mainly on remote sensing data (sea surface temperature and altimetry) available for July 2004. The numerical system is able to reproduce many of the circulation features described in the literature (e.g. Azores current recirculation in the Gulf of Cadiz, the upwelling jet, Mediterranean Water undercurrent, Mediterranean Outflow splitting, generation of meddies) and observed with remote-sensing data (e.g. the signature in sea surface temperature (SST) during a regime of upwelling relaxation).
Acknowledgements
This project was partially funded by Portugal's Fundação para a Ciência e Tecnologia as part of the DYNCOASTAL project. The work was also partially funded by the Portuguese Innovation Agency in the framework of programs that aims to increase the number of human resources with PhD in Portuguese companies. The authors would like to thank Prof. Delgado Domingos for offering them access to MM5 atmospheric results, and Ângela Canas for her support in the preparation of the MM5 files. The authors would also like to thank Luís Fernandes for the WAVEWATCH III wave results, and Pedro Pina for his advice and for providing access to remote-sensing data. A special thanks to Ricardo Lemos for his final revision of the text. The authors would also like to thank the HYCOM-US team for making the Atlantic solutions freely available. Finally, the first author would like to thank his wife Rute for her patience and support during the long process of drafting this article.