Variability of stalagmite-inferred Indian monsoon precipitation over the past 252,000 y
Fung, Inez Y.
Edwards, R. Lawrence
Day, Jesse A.
Kelly, Megan J.
Chiang, John C. H.
Date of Issue2015
Earth Observatory of Singapore
A speleothem δ18O record from Xiaobailong cave in southwest China characterizes changes in summer monsoon precipitation in Northeastern India, the Himalayan foothills, Bangladesh, and northern Indochina over the last 252 kyr. This record is dominated by 23-kyr precessional cycles punctuated by prominent millennial-scale oscillations that are synchronous with Heinrich events in the North Atlantic. It also shows clear glacial–interglacial variations that are consistent with marine and other terrestrial proxies but are different from the cave records in East China. Corroborated by isotope-enabled global circulation modeling, we hypothesize that this disparity reflects differing changes in atmospheric circulation and moisture trajectories associated with climate forcing as well as with associated topographic changes during glacial periods, in particular redistribution of air mass above the growing ice sheets and the exposure of the “land bridge” in the Maritime continents in the western equatorial Pacific.
Indian summer monsoon
Proceedings of the National Academy of Sciences of the United States of America
© 2015 The Author(s) (Published by National Academy of Sciences).This is the author created version of a work that has been peer reviewed and accepted for publication by Proceedings of the National Academy of Sciences of the United States of America, The Author(s) (Published by National Academy of Sciences). It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1073/pnas.1424035112].