Topographically Controlled Flow in the Isfjorden Trough and the West Spitsbergen Shelf

• Main Author: Vaardal-Lunde, Juni
• Format: Master Thesis
• Language: English
• Published: The University of Bergen 2011
• Subjects: Isfjorden; Topographically; Controlled flow; West Spitsbergen Shelf; 756213; VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452; Arctic; Arctic Ocean; Isfjord*; Spitsbergen
• Online Access: https://hdl.handle.net/1956/5578

A one layer numerical model demonstrates how the Atlantic Water (AW) from the West Spitsbergen Current (WSC) is topographically steered onto the West Spitsbergen Shelf (WSS) with a special emphasise on the Isfjorden Trough. Model results show that the WSC connects easier to the Isfjorden Trough than anywhere else on the shelf, letting the trough be exposed to warm and salty AW. When increasing the maximum velocity of the WSC more inflow into the troughs and consequently onto the WSS is observed in the model. The flow tends to follow steeper bathymetry when we increase the maximum velocity of the WSC and the topographical guiding is Rossby number dependent. Where isobaths converge, so will the streamlines, indicating stronger flow over steeper topography. This will increase the velocity shear and force the flow to follow deeper isobaths while circulating the troughs. The model is used to explain the January 2006 event, where an accumulation of warm water could be found in Isfjorden due to southerly winds. The simple one layer barotropic model gives a good approximation of the dynamical processes on the WSS, which plays a significant role in the cooling process of the WSC on its way to the Arctic Ocean. Master i Meteorologi og oseanografi MAMN-GEOF GEOF399