A high-resolution hydrodynamic-biogeochemical coupled model of the Gulf of Cadiz - Alboran Sea region

Abstract

The southern Iberia regional seas comprise the Gulf of Cadiz and the Alboran Sea sub-basins connected by the narrow Strait of Gibraltar. Both basins are very different in their hydrological and biological characteristics but are, also, tightly connected to each other. Integrative studies of the whole regional oceanic system are scarce and difficult to perform due to the relative large area to cover and the different relevant time-scales of the main forcing in each sub-basin. Here we propose, for the first time, a fully coupled, 3D, hydrodynamic-biogeochemical model that covers, in a single domain (~2km resolution) both marine basins for a 20-year simulation (1989-2008). Model performance is assessed against available data in terms of spatial and temporal distribution of biological variables. In general, the proposed model is able to represent the climatological distribution of primary and secondary producers and also the main seasonality of primary production in the various sub-regions of the analyzed basins. Potential causes of the observed mismatches between model and data are identified and some solutions are proposed for future model development. We conclude that most of these mismatches could be attributed to the missing tidal forcing in the actual model configuration. This model is a first step towards obtaining a meaningful tool to study past and future oceanographic conditions in this important marine region, which constitutes the unique connection between the Mediterranean Sea and the open ocean.