Abstract

The properties of the upper waters in the eastern subpolar North Atlantic between 1996 and the present day are examined. Around 7 Sv of these warm and saline waters flow northwards over the Greenland-Scotland Ridge into the Nordic Seas and Arctic Ocean, providing an estimated 250 TW and 245 kT/s of heat and salt to the region. Hence variations in the subpolar North Atlantic are propagated northwards. Between 1996 and the mid-2000s the upper waters in the eastern subpolar North Atlantic became warmer (+0.72 ºC) and saltier (+0.088), whilst nitrate and phosphate levels decreased (-2.00 μM and -0.14 μM respectively). These changes, out-with calculated errors, can be explained by the varying influence of southern versus subpolar water masses in the area as the Subpolar Gyre weakened and contracted. Since the early-2000s the Subpolar Gyre has been weaker than observed since 1992, or modelled since 1960-70. Hence upper waters within the eastern subpolar North Atlantic, and therefore Nordic Seas, maybe warmer, saltier and more depleted in nutrients than at any time in the last half century.