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，热带地区冰期-间冰期气候和环境变率的空间格局强调需要来自该地区的更长时间和更好的约束数据集，以充分了解强迫和潜在的反馈。热带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，大陆系统的环境变化通常幅度更大，空间异质性更强，而许多热带气候变率的早期记录都位于海洋环境中。因此，来自热带的陆地记录对于充分解决冰期-间冰期气候变率的区域变率以及与现有高纬度记录进行比较是特别必要的。该项目将有助于加深对过去40万年新热带古气候的了解，并将阐明中美洲关键地点佩特海姆伊茨<e:1>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，并将开发一种基于古气候的数据集成练习，该练习将用于实践本科课程。此外，该项目团队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，吸引大量全球学生。危地马拉佩特海姆伊茨<e:1>湖位于以信风迁移为主的区域，受亚热带大西洋盆地海温变化的影响。因此，它代表了了解美洲北部热带地区大尺度气候变化的关键空间节点。为了研究过去400 ka的气候和生态系统演变，研究人员将利用现有的pet<s:1>伊茨<e:1>湖的存档岩心来记录新热带温度（使用brGDGTs）和降水（使用叶蜡的δD值）的变化，以及陆地植被（使用叶蜡的δ13C值）对这些变化的响应。研究人员将把有机地球化学沉积重建的发现与先前发表的和目前正在进行的pet<s:2>伊茨<e:1>沉积学和孢粉学研究结合起来。代理模型比较工作也将利用这些综合重建和其他区域可用的记录与水同位素支持的GCM实验完成。该奖项反映了美国国家科学基金会的法定使命，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 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.