Warm deep-water ocean conveyor during Cretaceous time

Because the deep water is associated with its high-latitude sources, a warm deep ocean during Mesozoic-Cenozoic time is a challenge; there is no feasible physical mechanism that could maintain warm subpolar surface oceans in both hemispheres. The goal of this study is to explore a hypothesis that a warm deep ocean can coexist with relatively cool subpolar (high latitude) sea surface in one hemisphere and a warmer subpolar sea surface in the other. A series of numerical ocean circulation experiments confirms that the ocean meridional circulation can keep the abyssal ocean warm despite the northern subpolar surface water staying relatively cool.