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.

This study was motivated by a strong warming signal seen in mooring‐based and oceanographic survey data collected in 2004 in the Eurasian Basin of the Arctic Ocean. The source of this and earlier Arctic Ocean changes lies in interactions between polar and sub‐polar basins. Evidence suggests such changes are abrupt, or pulse‐like, taking the form of propagating anomalies that can be traced to higher‐latitudes. For example, an anomaly found in 2004 in the eastern Eurasian Basin took ∼1.5 years to propagate from the Norwegian Sea to the Fram Strait region, and additional ∼4.5–5 years to reach the Laptev Sea slope. While the causes of the observed changes will require further investigation, our conclusions are consistent with prevailing ideas suggesting the Arctic Ocean is in transition towards a new, warmer state.

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