Structure and Variability of the Jan Mayen Current in the Greenland Sea Gyre From a Yearlong Mooring Array.

The Jan Mayen Channel is located North of the Jan Mayen Island in the Nordic Seas, and is an important gateway for the exchanges of volume, heat and freshwater between the Greenland and the Norwegian basins via the Jan Mayen Current. Based on observations from moored instruments deployed on the shelf and the continental slope of the Jan Mayen Island from August 2017 to August 2018, we document the mean state and the variability of the currents, temperature and salinity and their associated vertical structure. We found that the main feature of circulation is an intense and permanent south‐eastward jet‐like current centered at 150 m depth, located on the 400 m depth slope, with a maximum mean magnitude of 7 cm·s−1. While the velocities recorded on the shelf are largely constant in speed and direction, without any strong seasonal cycle, the moorings located offshore are capturing larger anomalies on short time scales that are likely the signature of eddies passing across the mooring array. Overall, the variability of the transport across the section is correlated with the large‐scale wind pattern over the Nordic Seas, highlighting that the Jan Mayen Current is part of a complex system of currents that operates at larger scale in the region. Plain Language Summary: Located at the junction of the ridges separating the Iceland, Greenland, and Norwegian basins, the Jan Mayen Channel is considered as a route for Greenland Sea water entering into the Norwegian Sea. In 2017–2018, a high‐resolution (6 km spacing mean) mooring array was deployed at the entrance of the Jan Mayen Channel. This array consisting of six moorings progressing onshore to offshore provides a great opportunity to investigate water transport between Greenland and Norwegian Seas via the Jan Mayen Current. We reveal that the Jan Mayen Current presents different behaviors on the shelf and in the channel and we find that the current at the entrance of the channel is characterized by a strong jet‐like structure attached on the shelf with an intensity of about 7 cm·s−1. Thus, over 2017–2018, the Jan Mayen Channel was a regular and direct route for intermediate and deep water from the Greenland Sea to the Norwegian Sea. Key Points: The Jan Mayen Channel was a regular route for the Greenland Sea water to enter the Norwegian Sea in the 2017–2018 periodAn intense and permanent south‐eastward jet‐like current is detected at the entrance of the channel with a maximum magnitude of 7 cm·s−1The variability of Jan Mayen Current at the entrance of the channel is partly correlated with the wind stress curl [ABSTRACT FROM AUTHOR]