Deep water overflow in the Faroe Bank Channel; modelling, processes, and impact

More than 70% of the earth surface is covered by the ocean. The ocean is not static; it is in constant motion at many scales and circulates waters in coastal regions, the open seas and across ocean basins. The flow not only occurs in the surface of the ocean, as we can see in the form of waves or tides, but also deep beneath the surface, where deep-water currents circulate waters throughout the world’s oceans.

In certain very-localized regions, the flow of the deep-water has to travel over a sill in a narrow submarine channel. This overflow process mixes the deep water with overlying waters, creating new water masses with distinct temperature, salinity and density characteristics. The change of water mass characteristics not only affects the local environment, but also far distant regions.

The Faroe Bank Channel, which is located in the southern part of Faroe Islands, is one of the most important overflow regions in the world. It connects two huge ocean basins, the North Atlantic Ocean and the Nordic Seas, and the water mass produced there is an important ingredient of North Atlantic Deep Water, a water mass that found very nearly everywhere in the deep basins of the world’s oceans.

In this thesis, I use a high-resolution hydrodynamic model to study in detail the physics of deep-water overflows. Such models are a powerful research tool that can be used to study phenomena that are otherwise difficult to observe, and, when properly calibrated, can be used to predict how circulation may change under different circumstances.

The focus is on the Faroe Bank Channel, a relatively small region, which has a significant impact on the global ocean circulation and marine organisms that live in its environment.