x

Decoding the evolution of speleothem oxygen isotope and Asian Monsoon during the last deglaciation: An Update on iTRACE

He-Water-Poster.pdf (3.46 MB)
Poster thumbnail

Chengfei He1, Zhengyu Liu1, Bette Otto-Bliesner2, Esther C. Brady2, Chenyu Zhu3, Robert Tomas2, Jiang Zhu4, Alexandra Jahn5, Sifan Gu6, Jiaxu Zhang7, David Noone8 

1Atmospheric Science Program, Department of Geography, Ohio State University

2National Center for Atmospheric Research

3Department of Atmospheric and Oceanic Sciences, Peking University

4Department of Earth and Environmental Sciences, University of Michigan

5Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado at Boulder

6Physical Oceanography Laboratory, Ocean University of China

7Computational Physics and Methods (CCS-2) and Center for Nonlinear Studies (CNLS), Los Alamos National Laboratory

8College of Earth, Ocean, and Atmospheric Sciences, Oregon State University

Speleothem oxygen isotope records over Asian continent provide critical insights of the Asian monsoon variability across different time scales, though most of which are not well reproduced in numerical simulations. In order to further our understanding of the evolution of oxygen isotope and the Asian monsoon, we have been conducting a set of transient simulations of the last deglaciation (LGM to early Holocene) using the water isotope-enabled Community Earth System Model (iCESM), or the iTRACE experiments. It turns out that our simulations for the first time successfully reproduce the past speleothem water isotope evolution over the pan-Asia. We confirm mechanisms of the East Asian monsoon change in relation to the oxygen isotope records in previous studies and also show some new insights into them that the oxygen isotope response in Henrich 1 event is a result of the competition between melt water forcing and orbital forcing over the Asia except over East China, with other forcings (i.e. ice sheet and greenhouse gas) playing modest contrition. At East China, both melt water and orbital forcing enriches the speleothem oxygen isotope through upstream effect.

↑