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

合作研究：佩滕伊察湖 400ka 冰川-间冰期循环中的新热带气候和环境变化

• 批准号: 2002534
• 负责人: Bronwen Konecky
• 金额: $ 19.71万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2002534&HistoricalAwards=false
• 关键词: Collaborative; Research; Neotropical; climate; environmental

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.

从历史上看，我们对过去冰川周期中重大环境变化的大部分理解主要来自高纬度地区。然而，热带冰川-间冰期气候和环境变异性的空间格局突出表明，需要从该区域获得更长和更好约束的数据集，以充分了解强迫作用和潜在的反馈。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，与许多热带气候变异性早期记录所在的海洋环境相比，大陆系统中的环境变化通常在幅度上更大，在空间上更不均匀。因此，热带地区的陆地记录对于完全解决冰川-间冰期气候变异性的区域变异性以及与现有的高纬度记录进行比较特别必要。该项目将有助于加强对过去40万年来新热带古气候的了解，并将阐明中美洲一个关键地点--佩特恩伊特湖的温度、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、数据综合的练习，用于实践本科生课程。此外，项目组将在一份在线期刊上编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，面向全球大量学生受众。危地马拉的Petén Itzá湖位于一个以信风迁徙为主的地区，受到亚热带大西洋盆地海表面温度变化的影响。因此，它是了解美洲北部热带地区大尺度气候变异性的一个关键空间节点。研究人员将使用Petén Itzá湖现有的存档钻探岩芯来记录新热带地区温度(使用brGDGT)和降水(使用叶蜡的δD值)的变化，以及陆地植被对这些变化的响应(使用叶蜡的δ13C值)，以研究过去400ka的气候和生态系统演变。调查人员将把有机地球化学沉积重建的结果与Petén Itz以前发表的和目前正在进行的沉积学和孢粉学研究结合起来。还将利用这些综合重建和其他区域可获得的记录以及水同位素启用的GCM实验来完成代理模型比较工作。该奖项由地球科学部和大气和地球空间科学部通过古气候变化展望计划共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。