Major pathways of Atlantic water in the northern North Atlantic and Nordic Seas toward Arctic

TLDR

The inflow over the Scotland‑Greenland ridge and the establishment of the two‑branch Norwegian Atlantic Current are described in the context of northern North Atlantic circulation. Using 1,014 Lagrangian drifters and hydrography, the study identifies near‑surface Atlantic water pathways as currents exceeding 30 cm s⁻¹, revealing a western jet along the Polar Front and an eastern shelf‑edge branch that bifurcates into the Barents Sea. The Norwegian Atlantic Current preserves its two‑branch structure throughout the Nordic Seas, confining Atlantic water to a 200–600 km wide wedge.

Abstract

The major pathways of near‐surface Atlantic water in the northern North Atlantic and Nordic Seas are identified as current speeds above 30 cm/s, using 1014 Lagrangian drifters combined with previously published hydrography. The inflow over the Scotland‐Greenland ridge and establishment of the two‐branch Norwegian Atlantic Current (NwAC) are described in light of the circulation in the northern North Atlantic. The western branch of the NwAC appears as a jet in the Polar Front, topographically guided from the Iceland‐Faroe Front, through the Nordic Seas toward Fram Strait. The eastern branch starts as a shelf edge current above the Irish‐Scottish continental shelf, and after passing through the Faroe‐Shetland Channel, it continues northward along the Norwegian shelf edge toward the Arctic, with a branch bifurcating into the Barents Sea. The NwAC appears to maintain its two‐branch structure throughout the Nordic Seas, with the Atlantic water confined to a 200–600 km wide wedge.