Aeolian Dust Dynamics in Asia and their Teleconnection with Abrupt Climate Events in the Northern Hemisphere during the last 130.000 years: palaeoclimatic processes, feedbacks and impacts on Earths climate system

亚洲风沙动态及其与过去13万年北半球突变气候事件的遥相关：古气候过程、反馈和对地球气候系统的影响

• 批准号: 245339658
• 负责人: Professor Dr. Björn Machalett
• 金额: --
• 依托单位: Department of Geosciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/245339658?language=en
• 关键词: Aeolian; Dust; Dynamics; Asia; their

Understanding abrupt temperature shifts and millennial-scale climate oscillations, known as Dansgaard-Oeschger (DO) events, during the last glaciation, is an outstanding question in Quaternary paleoclimatology. High-resolution studies on Greenland ice cores pointed out that the onsets of abrupt Greenland warmings (DO events) were slightly preceded by decreasing Greenland dust deposition, reflecting a recessive aridity in the Asian deserts and thus reduced continental dust outbreaks into the Northern Hemisphere from the Asian dust sources. It remains a pressing problem to identify the synoptic atmospheric processes that account for the aridity swings in Asia and to decipher why those dynamics are coherent with, or moreover, slightly preceding DO events recorded in Greenland ice cores.Mineral dust in the atmosphere plays an important role in modifying climate, being both a product and a cause of climate change. Once deposited, accumulations of mineral dust provide a record of past climate and atmospheric circulation. The thick loess sequences found along the foothills and forelands of the central and east Asian high mountains are the only terrestrial climate archive and prime recorder of glacial-interglacial and sub-millennial changes in Asian dust transport dynamics. Loess records provide a unique insight into the climate driven continental dust load in the Northern Hemisphere at its major source. The project aims to test hypothesized links between abrupt climate variability recorded in Greenland and associated climate dynamics at Asian dust source areas. Furthermore, the project is designed to investigate to what extent the central and high Asian mountains are a crucial element within the sensitive glacier-desert-dust response system in interior Eurasia and to what extent they may be considered a pacemaker of suborbital global climate changes and an initiator of abrupt climate oscillations in the Northern Hemisphere.High resolution loess records in western Tajikistan, at the fringe of the Taklamakan Desert, and the Chinese Loess Plateau will be analyzed in order to derive an understanding of regional, large-scale aeolian transport dynamics and variability related to atmospheric circulation systems operating in the immediate circumference of the central and high Asian mountain ranges. Linking and correlating the established robust Asian dust proxy records with other high resolution climate records in the Northern Hemisphere constitutes a major aim of the project and will add to the knowledge about the land-atmosphere-ocean interactions and processes. The latter is indispensable for the understanding of recurrent interactions and complex feedbacks in past climate changes and thus fundamentally important to identify synoptic paleoclimatic patterns of atmospheric circulation in the Northern Hemisphere, which holds the key to understand drivers and triggers of abrupt climate dynamics in Earths climate system during the last 130.000 years

了解末次冰期期间的气温突变和千年尺度的气候振荡，即Dansgaard-Oeschger(DO)事件，是第四纪古气候学中的一个突出问题。关于格陵兰冰芯的高分辨率研究指出，格陵兰突然变暖(DO事件)的开始略早于格陵兰沙尘沉积的减少，反映了亚洲沙漠的隐性干旱，从而减少了从亚洲沙尘源进入北半球的大陆沙尘暴发。找出造成亚洲干旱波动的天气大气过程，并破译为什么这些动力学与格陵兰冰芯记录的DO事件一致或略早于此，仍然是一个紧迫的问题。大气中的矿物粉尘在改变气候方面发挥着重要作用，既是气候变化的产物，也是气候变化的原因。一旦沉积下来，矿物粉尘的堆积就会记录下过去的气候和大气循环。在中亚和东亚高山丘陵和前缘发现的厚黄土序列是唯一的陆地气候档案，是亚洲沙尘输送动力学中冰期-间冰期和亚千年变化的主要记录。黄土记录提供了一个独特的洞察气候驱动的大陆沙尘负荷在北半球的主要来源。该项目旨在测试格陵兰岛记录的突然气候变化与亚洲沙尘发源地相关气候动态之间的假设联系。此外，该项目旨在调查中亚和高亚洲山脉在多大程度上是欧亚大陆内陆敏感的冰川-沙漠-尘埃反应系统中的关键因素，以及在多大程度上它们可以被视为亚轨道全球气候变化的引领者和北半球突然气候振荡的始作俑者。将分析塔克拉玛干沙漠边缘塔吉克斯坦西部和中国黄土高原的高分辨率黄土记录，以了解与亚洲中部和高山脉周围大气环流系统运行有关的区域、大尺度风沙输送动力学和变异性。将已建立的稳健的亚洲尘埃代理记录与北半球的其他高分辨率气候记录联系起来并加以关联，构成了该项目的一个主要目标，并将增加对陆地-大气-海洋相互作用和过程的了解。后者对于理解过去气候变化中反复的相互作用和复杂的反馈是必不可少的，因此对于确定北半球大气环流的天气学古气候模式是至关重要的，这是理解过去130.000年地球气候系统突然气候动力学的驱动因素和触发因素的关键