Predictive ability of a linear theoretical model for the time-varying circulation in the Nordic seas and Arctic Ocean

• Main Authors: Sjur, A., Isachsen, P., Nilsson, J., Ryseth, M., Lacasce, J.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Arctic; Arctic Ocean; Nordic Seas
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5017839

In this study, we re-examine the use of an existing theoretical model for predicting the time-variable large-scale circulation along contours of constant ambient potential vorticity, given by f/H, in the Nordic Seas and Arctic Ocean. The theoretical model is an integral relation derived from the linear depth-averaged shallow water equations, and assumes that the circulation is driven by surface stresses and regulated by bottom drag. By applying this simplified model to a high-resolution numerical simulation, we assess its ability to accurately predict the circulation. Improvements from earlier examinations include better parametrization of stresses in ice-covered regions and higher resolution in the numerical simulation. Our results show that the linear model agrees well with the complex model. This indicates that much of the variability in the large-scale circulation can be explained by linear processes. However, we find that the performance of the linear model depends on the direction of the circulation, with the linear model overestimating anti-cyclonic circulation. This suggests that additional processes, not captured in the linear model, play a crucial role in anti-cyclonic circulation.