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Closing the sea level budget (between observed rise and the sum of its causes) has been a challenge, is an ongoing effort and has primarily concerned the global mean. Here, the authors use machine learning to identify sub-areas with similar trends to close the sea level budget on a regional level, with much reduced errors compared with 1-degree grid points.

Increasing Greenland Ice Sheet--melting is anticipated to impact water mass transformation in the subpolar North Atlantic and ultimately the meridional overturning circulation. Greenland meltwater redistribution pathways in and impact on the subpolar North Atlantic and overturning circulation is currently among the most debated topics. The manuscript provides new insights to both physical oceanographic processes and climate modelling. Based on a systematic setup of model configurations the importance of atmospheric feedbacks and mesoscale dynamics for specific regions of the subpolar North Atlantic are emphasized. This reaches beyond aspects of model techniques and also addresses the need for continued and improved observations in critical locations of the subpolar North Atlantic gyre circulation.

In this paper, a new hypothesis is put forward to explain the remarkable freshening of the Subpolar North Atlantic that peaked in 2016. The hypothesis emphasizes the increased surface circulation in the Labrador Sea region, following a reduction in heat loss to the atmosphere during the period 2000-2013. This new hypothesis, supported by the analysis of a very high resolution ocean model, contrasts with other studies that concluded to an overwhelming role of the reduced Atlantic Meridional Overturning Circulation in the freshening. In the present study, the AMOC decline is shown to account for not more than 27% of the freshening. Overall, this paper points out that surface properties of the Subpolar North Atlantic Ocean, which are important for European climate, cannot be understood in terms of AMOC variability only, but rather depend on the horizontal circulation at the ocean surface and on regional air-sea exchanges.

Marine plastics is a socially relevant topic that usually attracts public interest. It is especially relevant in the Galapagos which wants exceptional protection in view of its unique wildlife. The paper provides a methodology for effective management.

The authors investigate the main contributors to the seasonal variability in the strength of the Atlantic Meridional Overturning Circulation in the eastern North Atlantic subpolar gyre using a Lagrangian approach. They analyze trajectories from a hindcast model that permits eddies. The insights gained from the study are important and of interest to the broader scientific community, as well as potentially to the public. Specifically, the study finds that the strong seasonality in the strength of the AMOC is explained by the rapid circulation of upper limb waters. Parcels with sufficiently long circulation times within the gyre experience a combination of surface buoyancy loss and interior mixing, which filters out their seasonal thermohaline variability.