Observed covariability of Arctic and North Atlantic freshwater content

• Main Authors: Vredenborg, M., Rabe, Benjamin, Schauer, Ursula, Wekerle, Claudia
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: Arctic; Arctic Ocean; North Atlantic; North Atlantic oscillation; Sea ice; Subarctic
• Online Access: https://epic.awi.de/id/eprint/56624/; https://meetingorganizer.copernicus.org/EGU2018/EGU2018-15906.pdf; https://hdl.handle.net/10013/epic.d99529e0-5ecf-4a2c-8e1f-eece9482e3eb

Significant freshwater changes have recently been observed both in the Arctic Ocean and the subpolar North At- lantic. To investigate possible links, we compared the liquid freshwater content of the subarctic North Atlantic with the sum of liquid and solid freshwater content of the Arctic Ocean from observations. We found a distinct decadal anti-correlation of the freshwater anomalies in these two regions with anomalies of almost the same magnitude. An analysis of freshwater fluxes from the global Finite Element Sea ice Ocean Model (FESOM) and the CORE2 atmospheric forcing data set revealed that the observed freshwater variations resulted from changing freshwater transports. Furthermore these changes are correlated with the Arctic and North Atlantic Oscillation indices. We suggest that changing freshwater export from the Arctic Ocean to the subarctic North Atlantic responds to mul- tidecadal alternations of the dominant large-scale atmospheric variability. According to the present phase of this large-scale atmospheric variability, the freshwater accumulated during the previous decades in the Arctic Ocean might be released into the sub-Arctic Seas in the coming years. This has the potential to impact the North Atlantic meridional overturning circulation. To further investigate the involved processes, find the driver of freshwater trans- port changes and proof our hypotheses we show further results from the FESOM simulation and an analysis of the atmospheric forcing.