The dynamics of dense water cascades: from laboratory scales to the Arctic Ocean ...

• Main Author: Wobus, Fred
• Format: Article in Journal/Newspaper
• Language: English
• Published: University of Plymouth 2013
• Subjects: Mumerical Modelling; Dense water cascading; Gravity currents; Ocean circulation; Geophysical fluid dynamics; Arctic Ocean; Svalbard; Spitsbergen; Tidal mixing; Arctic
• Online Access: https://dx.doi.org/10.24382/4629; https://pearl.plymouth.ac.uk/handle/10026.1/1610

The sinking of dense shelf waters down the continental slope (or “cascading”) contributes to oceanic water mass formation and carbon cycling. Cascading is therefore of significant importance for the global overturning circulation and thus climate. The occurrence of cascades is highly intermittent in space and time and observations of the process itself (rather than its outcomes) are scarce. Global climate models do not typically resolve cascading owing to numerical challenges concerning turbulence, mixing and faithful representation of bottom boundary layer dynamics. This work was motivated by the need to improve the representation of cascading in numerical ocean circulation models. Typical 3-D hydrostatic ocean circulation models are employed in a series of numerical experiments to investigate the process of dense water cascading in both idealised and realistic model setups. Cascading on steep bottom topography is modelled using POLCOMS, a 3-D ocean circulation model using a terrain-following s-coordinate ...