Fig. 1: Circulation and temperature in Fram Strait and on the Northeast Greenland (NEG) continental shelf.

a Sketch of the ocean circulation in our study region. Purple arrows indicate the West Spitsbergen Current (WSC) transporting warm and salty Atlantic Water toward the Central Arctic Ocean. The blue arrow indicates the East Greenland Current (EGC) transporting fresh and cold Polar Water southwards. On the continental shelf, warm Atlantic Intermediate Water (AIW, light purple arrow) is transported through Norske Trough towards the 79 North Glacier (79NG). The extent of the floating ice tongues of the 79NG and Zachariæ Isstrøm are highlighted in yellow. b Study area on a global map. c Monthly mean (solid line) and associated standard deviation (shading) of simulated maximum temperature in the water column averaged over southern Norske Trough (black polygon shown in panel d). Gray solid and dashed lines indicate decadal averages and standard deviations respectively from historic hydrographic observations⁴⁵. d, e Mean velocity and potential temperature averaged over the AIW layer (defined by T > 1 ^∘C) and the Polar Water layer (defined by T < 1 ^∘C), averaged over 1970–2021. In white areas, the water masses are absent. Gray lines show isobaths at 200 m, 500 m, and 1000 m. The gray box at the 79NG in d indicates the region shown in Fig. 2a, b.