Collaborative research: Sources and circulation of intermediate and deep waters and their role in Campanian-Maastrichtian global cooling

晚白垩世(83-66 Ma)是晚白垩世早期极端温暖气候向古新世早期较凉爽气候转变的重要时期。来自多个大洋盆地的证据表明，这种转变伴随着海洋环流的重大变化。然而，这些海洋变化的性质及其在全球变冷中的作用仍是争论的主题。一些解释呼吁南方成分水(SCW)通过全球海洋扩张，可能通过低纬度上升流寒冷的深水造成大范围的冷却。其他人则认为，深水形成的区域来源的主导地位发生了变化，包括北大西洋来源的启动，导致了盆地内热量输送和气候的变化。这项合作研究涉及密苏里大学哥伦比亚分校、佛罗里达大学和密歇根大学的科学家，旨在解决这些争议。在他们早期发现的基础上，研究人员将从不同地点产生新的地球化学替代数据，这些数据将与现有数据相结合，限制可能的中深海来源和循环模式。他们还将通过气候模型模拟来评估古海洋学解释的合理性，测试关于门户和温室气体浓度对环流模式和深对流的影响及其与全球气候变化的联系的假设。这项工作的结果将增加我们对海洋环流和全球气候变化之间关系的了解，并通过这种方式为预测未来气候变化的努力做出贡献。此外，研究人员还将开展具体活动，促进普及教育和传播科学知识，并对青年科学家进行培训和指导，包括：(I)开发短片，向公众传播古海洋研究的兴奋和新颖性，并在研究人员的自然历史博物馆展示。(Ii)在每个参与机构对研究生进行培训，以及(Iii)通过出版物、在专业会议上的陈述以及将研究纳入研究生和本科生的课堂练习来传播成果。

The late Cretaceous period (83-66 Ma) saw an important climatic transition from the extreme warmth of the early Late Cretaceous to the cooler conditions of the Early Paleocene. Evidence from multiple ocean basins indicates that this transition was accompanied by major changes in ocean circulation. However, the nature of these oceanographic changes and their role in global cooling are the subject of debate. Some interpretations call for expansion of southern component water (SCW) through the global ocean, possibly causing widespread cooling through low-latitude upwelling of cold deep waters. Others suggest shifts in the dominance of regional sources of deep-water formation, including initiation of North Atlantic sources, leading to changes in intra-basinal heat transport and climate. This collaborative research, involving scientists from the University of Missouri-Columbia, the University of Florida, and the University of Michigan, seeks to resolve these controversies. Building on their earlier findings, the researchers will generate new geochemical proxy data from locations that will, in combination with existing data, constrain possible intermediate- and deep ocean sources and circulation modes. They will also evaluate the plausibility of paleoceanographic interpretations through climate model simulations, testing hypotheses regarding the effect of gateways and greenhouse gas concentrations on circulation patterns and deep convection and their links with global climate change. The results of this work will add to our knowledge about the relationship between ocean circulation and global climate change and, in this way, contribute to efforts to predict future climate change. In addition, the researchers will conduct specific activities that contribute to general education and the dissemination of scientific understanding, and the training and mentoring of young scientists including the following: (i) developing short videos to communicate the excitement and novelty of paleoceanographic research to the public, to be featured in displays at natural history museums at the researchers? home institutions, and posted on popular websites, (ii) training graduate students at each of the participating institutions, and (iii) disseminating results through publications, presentations at professional meetings, and by integrating research into lecture material, discussions, and classroom exercises for graduate and undergraduate students.