On the inter-connectivity of volume transports through Arctic Straits

Arctic heat and freshwater budgets are highly sensitive to volume transports through Arctic-Subarctic straits. Here we investigate how the volume transports through these straits adjust to each other to maintain a mass balance in the Arctic on annual timescales. To this end, we use three models; two coupled global climate models, one with a third-degree horizontal ocean resolution (HiGEM1.1) and one with a twelfth-degree horizontal ocean resolution (HadGEM3), and one ocean-only model with an idealized polar basin (tenth-degree horizontal resolution). The two global climate models indicate that there is a strong anti-correlation between the Bering Strait throughflow and the transport through the Nordic Seas, a second strong anti-correlation between the transport through the Canadian Artic Archipelago (CAA) and the Nordic Seas transport, and a third strong anti-correlation between the Fram Strait and the Barents Sea throughflows. We find that part of the strait correlations is due to the strait transports being coincidentally driven by large-scale atmospheric forcing patterns such as the Arctic Oscillation. However, there is also a role for fast wave adjustments of some straits flows to perturbations in other straits since atmospheric forcing of individual strait flows alone cannot lead to near mass balance fortuitously every year. Idealized experiments with an ocean model (NEMO3.6) that investigate such causal strait relations suggest that perturbations in the Bering Strait are compensated preferentially in the Fram Strait due to the narrowness of the western Arctic shelf and the deeper depth of the Fram Strait.