Collaborative Research: Neotropical climate and environmental change over 400ka of glacial-interglacial cycles from Lake Peten Itza

从历史上看，我们对过去冰川循环中重大环境变化的理解主要来自高纬度地区。然而，热带地区冰川-间冰期气候和环境变异的空间格局突出表明，需要该地区更长和更好的约束数据集，以充分了解强迫和潜在的反馈。热带地区在全球水分平衡和热量再分配中起着至关重要的作用。此外，与海洋环境相比，大陆系统中的环境变化一般幅度更大，空间差异更大，而热带气候变异的许多早期记录都位于海洋环境中。因此，从热带地区的陆地记录是特别必要的，以充分解决区域变化的冰川间冰期气候变化，并与现有的高纬度记录进行比较。该项目将有助于加深对过去40万年来新热带区古气候的了解，并将阐明中美洲佩滕伊察湖的温度，水文气候和植被变化。研究人员将指导学生与更广泛的公众进行科学交流，重点关注古气候研究的社会相关性，并将开发一个基于古气候的数据集成练习，用于实践本科课程。此外，该项目团队还将在一份在线期刊上撰写一篇描述古气候科学的开放获取文章，旨在激励和教育下一代科学家，覆盖全球大量学生受众。危地马拉的佩滕伊察湖位于信风迁移占主导地位的地区，受亚热带大西洋盆地海面温度变化的影响。因此，它是了解美洲北方热带大尺度气候变异的一个关键空间节点。研究人员将使用现有的，从佩滕伊察湖存档的岩心开发记录的变化新热带温度（使用brGDGT）和降水（使用δD值的叶蜡），以及陆地植被的响应（使用δ 13 C值的叶蜡）这些变化，以检查气候和生态系统的演变在过去的400 ka。研究人员将把有机地球化学沉积重建的结果与Petén Itzá先前发表的和目前正在进行的沉积学和孢粉学研究相结合。还将利用这些综合重建和其他区域现有记录以及水同位素启用的GCM实验完成代理模型比较工作。该奖项由地球科学部和大气与地球空间科学部通过气候变化古视角项目共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Historically, much of our understanding of significant environmental change in the past glacial cycles has primarily come from high latitude regions. However, the spatial pattern of glacial-interglacial climate and environmental variability in the tropics underscores the need for longer and better constrained data sets from the region to fully understanding forcings and potential feedbacks. The tropics play a crucial role in global moisture balance and heat redistribution. Additionally, environmental change in continental systems is also generally greater in amplitude and more spatially heterogeneous than in marine environments, where many of the early records of tropical climate variability are located. Thus, terrestrial records from the tropics are particularly necessary to fully resolve regional variability of glacial-interglacial climate variability and for comparison to existing high latitude records. This project will contribute to an enhanced understanding of Neotropical paleoclimate over the last 400 thousand years, and will illuminate temperature, hydroclimate, and vegetation shifts for a key location in Central America, Lake Petén Itzá. The researchers will mentor students in scientific communication with the broader public, focusing on the societal relevance of paleoclimate research, and will develop a paleoclimate-based, data-integrated exercise that will be used for hands-on undergraduate classes. Additionally, the project team will develop an open-access article describing paleoclimate science in an online journal aims to inspire and educate the next generation of scientists, reaching a large global student audience.Lake Petén Itzá, Guatemala, lies in a region dominated by trade wind migration and is influenced by sea surface temperature changes in the subtropical Atlantic basin. It thus represents a key spatial node for understanding large-scale climate variability of the northern tropics of the Americas. The investigators will use existing, archived drill cores from Lake Petén Itzá to develop records of changing Neotropical temperature (using brGDGTs) and precipitation (using δD values of leaf waxes), and the response of terrestrial vegetation (using δ13C values of leaf waxes) to these changes, in order to examine climate and ecosystem evolution over the past 400 ka. The investigators will integrate findings from the organic geochemical sedimentary reconstructions with previously published and currently on-going sedimentological and palynological research from Petén Itzá. Proxy-model comparison work will also be completed using these integrated reconstructions and other regionally available records with water isotope-enabled GCM experiments. This award is co-funded by the Division of Earth Sciences and Division of Atmospheric and Geospace Sciences by way of the Paleo Perspectives on Climate Change program.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.