NSFGEO-NERC: Collaborative Research: P2C2: MexiDrill: Developing a 350,000 year record of climate and environmental change in tropical North America

NSFGEO-NERC：合作研究：P2C2：MexiDrill：开发北美热带气候和环境变化 35 万年的记录

基本信息

批准号：
1804429
负责人：
Josef Werne
金额：
$ 28.83万
依托单位：
University of Pittsburgh
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1804429&HistoricalAwards=false
关键词：
NSFGEO NERC Collaborative Research P2C2

项目摘要

Understanding the mechanisms that caused past climate change is a key problem in paleoclimate research, and is critical for evaluating impacts of ongoing and future climate change. Sediments from Lake Chalco, just outside Mexico City, hold geologic, paleoenvironmental, and paleobiological information of value to the global scientific community, and directly relevant to the 20 million people living in the Basin of Mexico. Much of Mexico is projected to become drier in the coming decades and centuries in response to ongoing climate change; these anthropogenic changes will be superimposed on natural variability in climate systems. In central Mexico projections generally point to drying as a result of decreased rainfall during the summer rainy season and enhanced evaporation rates. Analysis of records of temperature and precipitation will provide a means to evaluate the history of climate preserved in Lake Chalco sediments. Results of this project will contribute to an improved understanding of climate and hydrological balance in one of the most densely populated urban centers on Earth. Hydrological balance is critical, impacting agriculture and drinking water as well as affecting vulnerability to disease. This study will enable more detailed assessment of volcanic history in the Mexico City region, which will also allow development of volcanic hazard assessment for the region that is based on a comprehensive understanding of past activity. The Basin of Mexico is one of the world's most heavily populated areas, and fallout deposits from large explosive eruptions have the potential to significantly disrupt the entire city. The team will incorporate field guides from Mexico into the "Flyover Country" mobile app, which will be available in English and Spanish. The project supports the development of a diverse, globally competitive STEM workforce by including early-to-mid career women in significant roles and through the inclusion of graduate students and postdoctoral researchers. To evaluate the role of low latitudes in initiating and propagating global changes, we need information regarding the geographical distribution and timing of abrupt changes in the tropics. A long and detailed climate record from central Mexico, the geographic center of North American tropical palaeoclimate sites, will enhance our understanding of the mid-latitude to tropical linkages in North American climate. The primary scientific objective of this joint NSF-GEO/NERC proposal is to obtain a continuous, high-resolution record of past changes in climate and biota in the North American tropics since the mid-Pleistocene. We will analyze a recently recovered ~350m lacustrine sedimentary sequence from the Lake Chalco basin on the southern outskirts of Mexico City. The Chalco sediment sequence is likely to provide a 350,000 year record of climate and environmental change, as well as a remarkable reconstruction of regional volcanic activity. Topics of particular interest include 1) glacial/interglacial variability in the influence of major climate modes such as migration of the InterTropical Convergence Zone (ITCZ) and Westerlies, 2) orbital scale variability, particularly the influence of precession on the location of the ITCZ and its influence on the Mesoamerican Monsoon, and 3) millennial scale variability during glacial periods and terminations. Interplay between air masses controlled by temperature changes in the Pacific and Atlantic basins is stronger in Chalco than at other sites, and hydroclimate changes are amplified due to its high altitude location. This will be among the longest archives of climate, environment, and biota from North America, from a region presently lacking such records.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.

了解引起过去气候变化的机制是古气候研究的关键问题，对于评估持续和未来气候变化的影响至关重要。来自墨西哥城郊外的Chalco湖的沉积物，持有地质，古环境和古生物学信息，及其对全球科学界的价值信息，直接与居住在墨西哥盆地的2000万人有关。墨西哥的大部分地区预计在未来几十年中会变得更干燥，并且由于持续的气候变化，墨西哥几个世纪以来。这些人为变化将叠加在气候系统中的自然变化上。在墨西哥中部，预测通常是由于夏季雨季降雨量下降而导致的，蒸发率提高。温度和降水记录的分析将提供一种评估Chalco湖沉积物中保存的气候历史的手段。该项目的结果将有助于提高人们对地球上人口最密集的城市中心之一的气候和水文平衡的了解。水文平衡至关重要，影响农业和饮用水，并影响疾病的脆弱性。这项研究将对墨西哥城地区的火山历史进行更详细的评估，这也将允许开发基于对过去活动的全面了解该地区的火山危害评估。墨西哥的盆地是人口稠密的地区之一，大型爆炸爆发的后果沉积物有可能严重破坏整个城市。该团队将将墨西哥的现场指南纳入“天桥国家”移动应用程序，该应用将以英语和西班牙语提供。该项目通过包括重要角色的早期至中间职业女性以及包括研究生和博士后研究人员的成员来支持各种全球竞争性的STEM劳动力的发展。为了评估低纬度在启动和传播全球变化中的作用，我们需要有关热带突然变化的地理分布和时机的信息。墨西哥中部（北美热带古气候地理地理中心）的漫长而详尽的气候记录将增强我们对北美气候中热带联系的中纬度的理解。该联合NSF-GEO/NERC提案的主要科学目标是获得自临时新世以来北美热带地区气候和生物群体过去变化的连续高分辨率记录。我们将分析墨西哥城南部郊区的Chalco湖盆地最近回收约350m湖的沉积序列。 Chalco沉积物序列可能会提供350,000年的气候和环境变化记录，以及对区域火山活动的显着重建。特别感兴趣的主题包括1）主要气候模式的影响（例如，热带收敛区域迁移（ITCZ）和西风的迁移，2）轨道尺度变异性，尤其是进取对ITCZ的影响，及其对中美洲季度的影响和3）量表变化的术语及其在刻度上的变化。在Chalco中，由太平洋和大西洋盆地温度变化控制的空气质量之间的相互作用比其他地点更强，并且由于其高海拔位置，氢气气候变化会放大。这将是目前缺乏此类记录的地区的气候，环境和生物群岛最长的档案之一。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估审查标准来通过评估来支持的。