Project Details
Projekt
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
Applicant
Professor Dr. Björn Machalett
Subject Area
Physical Geography
Term
from 2014 to 2017
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 244672114
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.
DFG Programme
Research Fellowships
International Connection
USA
