Senckenberg Research

CAHOL- Central Asian Holocene Climate

In an integrated approach, the interplay between the position and strength of the Westerlies and the summer monsoon precipitation in Central Asia during the Holocene will be investigated. Modern observations and model simulations show that the position of the Westerlies, which is controlled by climate changes in the North Atlantic, is limiting the Asian monsoon region to the north. This link between the regional monsoon and the position of the Westerlies in Asia is of crucial importance for the precipitation regime in large areas of Asia. However, the brevity of instrumental data series does not allow a reliable statement about the periods and interactions of these climate phenomena. In the different CAHOL projects the hypothesis is tested that long-lasting phases of the Atlantic Multidecadal Oscillation (AMO) or the North Atlantic Oscillation (NAO) can cause tipping points in the Asian monsoon climate by a long-term shift of the Westerlies. For this purpose, new sediment archives are investigated in the Westerlies region (Central Tain Shan, Chatyr Kol, SE Kyrgyzstan), in the transition from the Westerlies to the Indian monsoon (northern Arabian Sea) and in the area of the East Asian monsoon (South China Sea) to understand the long-distance teleconnections in the climate system between the North Atlantic, the Westerlies and the monsoon system (Fig. 2). The results of the studies form the basis for a numerical modeling of the tipping points by use of global and regional climate simulations. This helps not only to better understand the interplay of the Asian monsoon system with climate oscillations in the North Atlantic but also to improve the estimation of regional effects and dangers of recent climate changes in Central Asia.

Fig. 2: Study areas of the different working groups: WP1 investigates sediments from the Westerly–dominated Chatyr Kol (Kyrgyzstan), WP2 from the transition zone between the Westerlies and the Indian monsoon (northern Arabian Sea) and WP3 from the area of the East Asian monsoon (South China Sea).


Involved institutes and working groups

Helmholtz-Centre Potsdam - GFZ German Research Centre for Geosciences
Section: Climate Dynamics and Landscape Evolution: Prof. Dr. Achim BrauerDr. Jens Mingram

Universität Hamburg
Institute for Geology, Working group Biogeochemistry: Prof. Dr. Kay-Christian EmeisDr. Birgit Gaye, Dr. Nicole Burdanowitz

Christian-Albrechts-Universität zu Kiel
Institute of Geosciences: Dr. Joachim Segschneider

Technische Universität Braunschweig
Institute of Geosystems and Bioindication: Prof. Dr. Antje Schwalb, Dr. Falko Turner

Eberhard Karls Universität Tübingen, Department of Geosciences
Work Group Micropalaeontology: Dr. Hartmut Schulz

Freie Universität Berlin
Institute of Meterology, Climate System Modeling Working Group: Prof. Dr. Ulrich Cubasch, Dr. Bijan Fallah

Leibniz Centre for Tropical Marine Research (ZMT) Bremen
Biogeochemistry/Geology: Dr. Tim Rixen

MARUM, Center for Marine Environmental Sciences, Universität Bremen: Dr. Mahyar MohtadiProf. Dr. Michael SchulzDr. Stephan Steinke

Max Planck Institute for Biogeochemistry (MPI) Jena: Prof. Dr. Gerd Gleixner


Research projects

CAHOL is divided into four work packages:

CAHOL is divided into four work packages:
WP 1: Analysis of lake sediments from the Chatyr Kol (Kyrgyzstan) including range of species and carbon isotopy of microfossils as indicators of water development and carbon cycle
WP 2: Arabian Sea
WP 3: South China Sea
M: CAHOL Modeling