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East Asian summer monsoon precipitation variations in China over the last 9500 years: A comparison of pollen-based reconstructions and model simulations.
- Source :
-
Holocene . Apr2016, Vol. 26 Issue 4, p592-602. 11p. 2 Charts, 5 Graphs, 1 Map. - Publication Year :
- 2016
-
Abstract
- To better understand the long-term changes of the East Asian summer monsoon precipitation (Pjja), quantitative reconstructions and model simulations are needed. Here, we develop continental-scale pollen-based transfer functions for Pjja with weighted averaging–partial least squares (WA-PLS) regression and a Bayesian multinomial regression method. We apply these transfer functions to a set of fossil pollen data from monsoonal China for quantitatively reconstructing the Pjja changes over the last 9500 years. We compare the reconstructions with Pjja simulations from a coupled atmosphere–ocean–sea ice general circulation model (the Kiel Climate Model, KCM). The results of cross-validation tests for the transfer functions show that both the WA-PLS model (r2 = 0.83, root mean square error of prediction (RMSEP) = 112.11 mm) and the Bayesian model (r2 = 0.86, RMSEP = 107.67 mm) exhibit good predictive performance. We stack all Pjja reconstructions from northern China to a summary curve. The stacked record reveals that Pjja increased since 9500 cal. yr BP, attained its highest level during the Holocene summer monsoon maximum (HSMM) at ~7000–4000 cal. yr BP and declined to present. The KCM output and the reconstructions differ in the early-Holocene (~9500–7000 cal. yr BP) where the model suggests higher Pjja than the reconstructions. Moreover, during the HSMM, the amplitude of the Pjja changes (~20–60 mm above present) in simulations is lower than the reconstructed changes (~70–110 mm above present). The rising (declining) Pjja patterns in reconstructions before (after) the HSMM are more pronounced and fluctuating than in simulations. Other palaeohydrological data such as lake-level reconstructions indicate substantial monsoon precipitation changes throughout the Holocene. Our results therefore show that the KCM underestimates the overall amplitude of the Holocene monsoon precipitation changes. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09596836
- Volume :
- 26
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Holocene
- Publication Type :
- Academic Journal
- Accession number :
- 113906023
- Full Text :
- https://doi.org/10.1177/0959683615612564