Collaborative Research: Bioclimatic Reconstruction of the Past 50,000 Years from Eolian Sequences in the Westerlies-Dominated Central Asia

合作研究：根据西风带主导的中亚风成序列重建过去五万年的生物气候

• 批准号: 0623514
• 负责人: Kam-biu Liu
• 金额: $ 14万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0623514&HistoricalAwards=false
• 关键词: Collaborative; Research; Bioclimatic; Reconstruction; Past

This study aims to reconstruct a detailed bioclimatic history of the last 50,000 years in the westerlies-dominated Central Asia based on a multi-proxy study of several thick eolian sections. The westerlies-dominated region includes the Dzungaria Basin (northwestern Xinjiang) and the Kazakhstan Hills and Plains (eastern Kazakhstan) that mark the conjunction between the East Asian Monsoon and the westerlies-dominated "European" climate systems. This investigation will produce paleoclimatic proxy records from a suite of loess/paleosol sections that span the past 50,000 years. A combination of geophysical, geochemical, and geobiological proxies will be used in the reconstruction. Bioclimatic transfer functions based on pollen, snails, carbon-13 of organic matter, and environmental magnetic parameters will be produced along three N-S transects to provide regional coverage of bioclimatic changes during the past 50,000 years. A relatively high-resolution reconstruction of bioclimatic changes from eolian sequences in the study area shall provide a context for understanding hemispheric- and global-scale forcing mechanisms and ocean-atmosphere-continent couplings throughout the past 50,000 years. The bioclimatic reconstruction will permit a better understanding of not only the interacting history between the East Asian monsoons and the westerlies but also the teleconnections between the North Atlantic Oscillation (NAO) and the Pacific North American (PNA) Oscillation. The outcomes of this research will improve understanding of the land-air coupled feedback mechanisms and validate the hypothesis that atmospheric aerosol influx might have triggered global atmospheric CO2 changes. This project will enhance partnership possibilities in a global network of aerosol studies by establishing collaborations among international institutions (U.S., Kazakhstan, and China) and the reconstructed bioclimatic history will provide insight for combating the ongoing problem of human-exacerbated desertification in Central Asia.

本研究旨在基于对几个厚风成层的多代理研究，重建以西风为主的中亚过去 5 万年的详细生物气候历史。西风主导地区包括准噶尔盆地（新疆西北部）和哈萨克斯坦丘陵和平原（哈萨克斯坦东部），标志着东亚季风与西风主导的“欧洲”气候系统的交汇处。这项调查将从一组跨越过去 5 万年的黄土/古土壤剖面中产生古气候代理记录。重建中将结合使用地球物理、地球化学和地球生物学代理。将沿着三个南北断面生成基于花粉、蜗牛、有机物碳 13 和环境磁参数的生物气候传递函数，以提供过去 5 万年生物气候变化的区域覆盖。根据研究区域的风成序列对生物气候变化进行相对高分辨率的重建将为理解过去五万年的半球和全球尺度的强迫机制以及海洋-大气-大陆耦合提供背景。生物气候重建不仅可以更好地了解东亚季风和西风之间的相互作用历史，还可以更好地了解北大西洋涛动（NAO）和北美太平洋涛动（PNA）之间的遥相关。这项研究的结果将增进对陆地-空气耦合反馈机制的理解，并验证大气气溶胶流入可能引发全球大气二氧化碳变化的假设。该项目将通过在国际机构（美国、哈萨克斯坦和中国）之间建立合作，增强全球气溶胶研究网络中伙伴关系的可能性，而重建的生物气候历史将为应对中亚地区持续存在的人为加剧的荒漠化问题提供见解。