Recent studies of Arctic Amplification (AA) suggest that the Arctic has been warming between three to four times faster compared to the global average. The loss of sea ice in the Arctic has been one of the most evident manifestations of warming climate over the past several decades. This decline has been most pronounced in the Barents/Kara seas during winter and in the western Arctic during summer. Changes in the Arctic sea ice cover can be both a cause and a consequence of anomalous atmospheric and oceanic warming. In case of the winter trend, some earlier studies have suggested that factors other than atmospheric forcing, e.g., ocean heat transport and storage, are responsible for the observed sea ice retreat. Moreover, results from models participating in Phase 6 of the Coupled Model Intercomparison Project (CMIP6) suggest an emergent constraint linking oceanic heat convergence to declining sea ice cover in the Arctic Ocean. At the same time, significant biases in individual simulated sea ice states persist, resulting in the continued large CMIP model spread. The limited skill in model historical simulations of the Arctic climate system hinders interpretation of their results and affects the reliability of their future projections.

In this presentation we will address some of these limitations, focusing on the importance of oceanic heat transport from the Nordic Seas, its convergence and impact on the sea ice over the Barents Sea, and the remaining outflow into the central Arctic. Results from the Regional Arctic System Model (RASM), at varying spatial resolutions and forced with an atmospheric reanalysis or fully coupled, will be evaluated to demonstrate a relatively wide range of the simulated volume fluxes into the Barents Sea. Apparent coupled linkages between oceanic volume and heat fluxes, sea ice cover, and the oceanic heat convergence over the Barents Sea will be demonstrated. The importance of spatial resolution in representing some critical processes related to ocean mesoscale, sea ice characteristics, and air-sea coupling in the region will be discussed. Finally, the need for expanded long-term measurements to reduce uncertainties in the observational estimates of oceanic fluxes in and out of the Barents Sea will be rationalized.