Constraining Glacial to Recent climate shifts over continental China from clumped isotope measurements on terrestrial carbonates from the loess plateau (Invited)
Abstract
Numerous paleoclimate archives have revealed that the East Asian Monsoon has undergone significant past variations on orbital and suborbital timescales. However until recently we have had no good way to separate the temperature and water isotope signals from carbonate archives, an important goal in order to place quantitative constraints on the sensitivity of monsoonal climates to past climate forcing's. Here we present a detailed reconstruction of changes in temperature and the oxygen isotope composition of meteoric waters from the Last Glacial Maximum to present based on clumped isotope measurements on terrestrial carbonates from Puxian in the central Chinese loess plateau. We will discuss the systematics of interpreting the clumped isotope signatures from terrestrial carbonates and also present preliminary data from other sites on the loess plateau. Comparison of our data for Puxian with climate model outputs reveals that models that best fit our clumped isotope based temperature reconstructions also simulate enhanced planetary scale waves at the last glacial maximum, a feature which produces enhanced glacial cooling over continental China. Meteoric water signals reconstructed from clumped isotope measurements are also broadly reproduced by simulations with the isotope enabled LMDZ model, thereby allowing the mechanisms driving past changes in the isotopic composition of precipitation to be explored with more confidence in the model. The mechanistic insights derived from our model-data comparison highlight the additional benefit of having quantitative temperature and water isotope estimates and therefore the power of the clumped isotope approach.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMPP21D..05E
- Keywords:
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- 4926 PALEOCEANOGRAPHY Glacial