Through transporting heat around the world and thereby regulating global climate, ocean circulation is an integral part of Earth's climate system that likely changed substantially on glacial-interglacial timescales in the deep North Atlantic Ocean. However, quantitative records on deep-water dynamics in the North Atlantic older than ~1 Myr are sparse and typically of low temporal resolution. Here we provide a new record on northern- versus southern-sourced waters in the deep North Atlantic at a yet unprecedented temporal resolution. Our record is based on a novel approach (Atlantic-Pacific bottom-water temperature (BWT) difference) for an interval comprising the onset of larger-scale glaciations in the Northern Hemisphere, the Plio-Pleistocene transition (~2.65–2.4 Ma; Marine Isotope Stages G1–95). We thus have generated a new, millennial-scale-resolution BWT record based on benthic foraminiferal Mg/Ca from Ocean Drilling Program Site 849 in the East Pacific backed up with a new neodymium-isotope record on glacial-interglacial-scale resolution. The difference between our new BWT record (Site 849) and previously available BWTs from Integrated Ocean Drilling Program Site U1313 in the North Atlantic was used to decipher changes between southern- and northern-sourced waters in the deep North Atlantic. In accordance with previous studies, we document an increased influence of deep waters from high southern latitudes during glacials at the expense of northern-sourced waters. Perhaps even more importantly, our new record is highly relevant for the determination of geochemically-based sea-level records from the deep North Atlantic, which was yet limited by quantitative estimates of deep-water masses at a sufficient, (sub-)millennial-scale resolution.

通过在全球范围内输送热量并调节全球气候，海洋环流是地球气候系统不可或缺的一部分，在北大西洋深海的冰川间时间尺度上可能发生了很大变化。然而，有关北大西洋深水动力学的定量记录（年龄小于1 Myr）很少，并且通常具有较低的时间分辨率。在这里，我们以前所未有的时间分辨率，提供了北大西洋深海北部水源与南部水源的新记录。我们的记录基于一种新颖的方法（大西洋-太平洋底水温度（BWT）差异），其间隔包括北半球较大规模冰河的爆发，上新世-上新世过渡（〜2.65-2.4 Ma；海洋同位素阶段G1-95）。因此，我们产生了一个新的 基于东太平洋海洋钻探计划站点849底栖有孔虫Mg / Ca的千禧年尺度分辨率BWT记录，并以冰晶间冰川规模分辨率的新钕同位素记录作为后盾。我们新的BWT记录（站点849）与北大西洋综合海洋钻探计划站点U1313先前可用的BWT之间的差异被用来解释北大西洋深海南部和北部水域之间的变化。根据以前的研究，我们记录了冰川期间南部高纬度地区深水的影响增加，但北源水却有所减少。也许更重要的是，我们的新记录与确定北大西洋深处基于地球化学的海平面记录高度相关，