a, Correlation (colour bar) of the vertically averaged ocean density (at 1,000–2,500 m) with the DLSD index (as defined in ref. 4; green box, 1,000–2,500 m average) in a 340-year present-day control run of the HiGEM model (see ref. 36). b, Climatology of the modelled meridional ocean velocity (in m s−1) averaged between 30° N and 35° N, illustrating the modelled position of the DWBC. The y axis shows the water depth in metres. c, Cross-correlations between the modelled average DWBC flow speed in the pink box in panel b and indices of DLSD and AMOC at 45° N (the dashed line omits the Ekman component). We note that the box over which the DWBC flow index in panel c is averaged has changed with respect to Fig. 1, in order to take into account of the fact that the return flow is deeper in the HiGEM model than in HadGEM3-GC2.