Top panels: 50 % annual sea ice concentration (dashed blue line) and buoyancy fluxes, where negative values (blue shading) are associated with sea ice formation; note that these areas expand equatorward in the LGM simulation.
Thus as sea ice expands in a cooler climate, the high - latitude oceanic heat loss to the atmosphere is inhibited, the thermohaline circulation weakens, and the sinking regions move equatorward, leading to a shallower and weaker deep circulation.