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 Earth's 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: 244672114
• 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 Fellowships
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/244672114?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 extend 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 on the Chinese Loess Plateau will be analysed 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 Earth's climate system during the last 130.000 years.

了解末次冰期的温度突变和千年尺度气候振荡，即Dansgaard-Oeschger（DO）事件，是第四纪古气候学中的一个突出问题。对格陵兰冰芯的高分辨率研究指出，格陵兰岛突然变暖（DO事件）的发生略早于格陵兰岛尘埃沉积的减少，反映了亚洲沙漠的隐性干旱，从而减少了从亚洲尘埃源进入北方半球的大陆尘埃爆发。它仍然是一个紧迫的问题，以确定天气大气过程，占干旱的波动，在亚洲和破译为什么这些动力学是一致的，或者说，稍早于格陵兰冰芯记录的DO事件，在大气中的矿物粉尘在改变气候中起着重要的作用，既是气候变化的产物和原因。一旦沉积下来，矿物尘埃的积累提供了过去气候和大气环流的记录。沿着中亚和东亚高山山麓和前陆发现的厚层黄土序列是唯一的陆地气候档案和亚洲沙尘输送动力学的冰期-间冰期和近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粉尘负荷在北方在其主要来源。该项目旨在检验格陵兰记录的气候突变与亚洲沙尘源区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亚洲高山在何种程度上是欧亚大陆内部敏感的冰川-沙漠-尘埃反应系统中的关键因素，以及在何种程度上它们可被视为亚轨道全球气候变化的起搏器和北方半球突然气候振荡的启动器。将对中国黄土高原的气候变化进行分析，以了解与中亚和高亚洲山脉周边大气环流系统有关的区域大规模风成输运动力学和变率。将已建立的可靠的亚洲尘埃代用记录与北方其他高分辨率气候记录联系起来并使之相互关联是该项目的一个主要目标，并将增加关于陆地-大气-海洋相互作用和过程的知识。后者对于理解过去气候变化中经常性的相互作用和复杂的反馈是不可或缺的，因此对于确定北方半球大气环流的天气古气候模式至关重要，这是理解过去13万年地球气候系统中突然气候动力学的驱动因素和触发因素的关键。