The role of wind stress in the Arctic and North Atlantic freshwater covariability

• Main Authors: Kovacs, Tamas, Gerdes, Rüdiger
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: Arctic; North Atlantic
• Online Access: https://epic.awi.de/id/eprint/48307/; https://epic.awi.de/id/eprint/48307/1/FAMOS2018_kovacs.pdf; https://hdl.handle.net/10013/epic.497fcbe8-8cdc-47b1-9bbe-8d9fbde31db4

Observations from recent decades show significant salinity anomalies in the Arctic and the subpolar North Atlantic oceans. The evolution of their freshwater budgets has been the focus of many studies, most of which suggest a link between them. However, the nature and the significance of this link is still disputed, as are the driving forces behind it. Our aim was to perform a series of numerical simulations of the freshwater system of the Arctic and the subpolar North Atlantic oceans and to assess the role of wind stress in shaping it. For this we used the Max Planck Institute Earth System Model and ran model experiments in a partially coupled configuration applying the so called Modini-method with prescribed wind forcing. We constructed idealized scenarios of wind stress forcing associated with large-scale patterns of observed atmospheric variability. We present our results from scenarios representing prolonged positive or negative states of the AO/NAO. We also analyze the response to a sudden change from one state to another with particular focus on the Arctic and the North Atlantic freshwater reservoirs and the fluxes between them. This enables us to simulate the high freshwater content observed in the Beaufort Gyre concurrent with an unusually persistent anticyclonic wind pattern in the Arctic in recent years, and to study the effect of large-scale circulation shifts on Arctic freshwater export and thus salinity anomalies in the subpolar North Atlantic Ocean.