Fig. 1

The major circulation elements and the corresponding meridional heat transport distribution in the subpolar North Atlantic Ocean. a The red and yellow mark the warm currents and blue and purple denote the cold currents. The map illustrates that the northward flow carries relatively warm water and southward flow generally transports colder water, leading to northward meridional heat transport in the subpolar North Atlantic Ocean. The labels are Denmark Strait (DS), Faroe Bank Channel (FBC), East and West Greenland Currents (EGC and WGC, respectively), North Atlantic Current (NAC), Denmark Strait overflow (DSO), Deep Western Boundary Current (DWBC), Iceland-Scotland Overflow (ISO), and Mid-Atlantic-Ridge (MAR). The figure is made by H. Furey, Woods Hole Oceanographic Institution and modified from Fig. 1 in Lozier et al. (2017). Green line denotes the OSNAP East section between Greenland and Scotland. b Meridional heat transport from surface to bottom zonally accumulated from Greenland towards Scotland along the OSNAP East line. Black solid line is the heat transport computed from in situ hydrographic observations in June 2014. Red solid line is the mean heat transport computed from 1/12 degree HYCOM simulation (1992–2014) and red shaded area represents the uncertainties measured by standard deviation. The vertical black dashed lines mark locations of the OSNAP glider transect endpoints