The Arctic Ocean surface and bottom circulation estimated from altimetry and hydrography

• Main Authors: Kallmyr, J., Nilsson, J., Isachsen, P., Sjur, A., Chafik, L.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Arctic; Arctic Ocean; Isachsen; Nordic Seas
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021543

The number of direct observations of ocean currents in the central Arctic are still limited. Here, the Arctic Ocean Circulation is studied using available altimetric, bathymetric and hydrographic data sets. Based on earlier theoretical frameworks of the Arctic Ocean Circulation, such as Nøst and Isachsen (2003), key concepts such as topographic steering of the flow field, and the degree to which it is eqvivalently barotropic are evaluated. It is found that the surface flow, which is derived from altimetry, is generally aligned along large-scale depth contours. A closer study of central regions in the Arctic Mediterranean also show high alignment along local depth contours in both the Nordic Seas and the Arctic Ocean. While the bottom flow is estimated through thermal wind balance, and as such have a lower horizontal resolution, many of the same features are seen, suggesting that the circulation is generally eqvivalent barotropic. Local regions of cross-slope flow are identified as areas of inflow (outflow) to (from) the Arctic Ocean, suggesting that the local relative vorticity is enough to break topographic steering in these regions. Addtionally, different hydrographic data sets yield slightly different thermal wind velocities, but which can affect the direction and magnitude of the bottom flow.