Deep Circulation in the Colombian Caribbean and its Interaction with Bathymetric Features Close to La Guajira Peninsula and Nicaraguan Rise

Observations from a full water-column mooring at 3675 m of water depth offshore the Guajira Peninsula in Colombia and results from high-resolution numerical simulations indicate an active deep ocean circulation in the region. One of the main features identified in the observations is a semi-permanent current flowing towards the NNE which is nearly vertically-uniform from 1000 m depth to near theseabed, and which, to our knowledge, has not been reported in peer-reviewed literature. This deep current shows evidence of oscillations with periods of approximately 60 days and clear bottom current intensification, which are characteristic of topographic Rossby waves. The steep bathymetry close to the mooring provides a setting for the waves to develop and transit.To fully understand what was registered by the mooring and what are the dynamics that dominate the deep-water circulation in the region, we take a look in the Caribbean basin looking particularly for the interaction of the currents with the bathymetric most relevant features (Nicaraguan and Beata rise). The horizontal extent of the Rossby wave-like events or others, as well as possible generation mechanisms at the basin scale, are examined using results from high-resolution numerical simulations configured specifically to recreate the circulation in the Colombian basin during 20 years which include the observation period.