Articles | Volume 12, issue 7
Clim. Past, 12, 1583–1590, 2016
https://doi.org/10.5194/cp-12-1583-2016
Clim. Past, 12, 1583–1590, 2016
https://doi.org/10.5194/cp-12-1583-2016

Research article 28 Jul 2016

Research article | 28 Jul 2016

Quantification of southwest China rainfall during the 8.2 ka BP event with response to North Atlantic cooling

Yuhui Liu1,2 and Chaoyong Hu1 Yuhui Liu and Chaoyong Hu
  • 1State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, PR China
  • 2Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, PR China

Abstract. The 8.2 ka BP event could provide important information for predicting abrupt climate change in the future. Although published records show that the East Asian monsoon area responded to the 8.2 ka BP event, there is no high-resolution quantitative reconstructed climate record in this area. In this study, a reconstructed 10-year moving average annual rainfall record in southwest China during the 8.2 ka BP event is presented by comparing two high-resolution stalagmite δ18O records from Dongge cave and Heshang cave. This decade-scale rainfall reconstruction is based on a central-scale model and is confirmed by inter-annual monitoring records, which show a significant positive correlation between the regional mean annual rainfall and the drip water annual average δ18O difference from two caves along the same monsoon moisture transport pathway from May 2011 to April 2014. Similar trends between the reconstructed rainfall and the stalagmite Mg ∕ Ca record, another proxy of rainfall, during the 8.2 ka BP period further increase the confidence of the quantification of the rainfall record. The reconstructed record shows that the mean annual rainfall in southwest China during the central 8.2 ka BP event is less than that of present (1950–1990) by  ∼  200 mm and decreased by  ∼  350 mm in  ∼  70 years experiencing an extreme drying period lasting for  ∼  50 years. Comparison of the reconstructed rainfall record in southwest China with Greenland ice core δ18O and δ15N records suggests that the reduced rainfall in southwest China during the 8.2 ka BP period was coupled with Greenland cooling with a possible response rate of 110 ± 30 mm °C−1.

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Short summary
The 8.2 ka BP event, a global climate anomaly that occurred 8200 years ago, could provide climate teleconnection information for the simulation of abrupt climate changes, but there are few quantitative reconstructions of this event. This paper provides a 10-year resolution rainfall record from the East Asian monsoon area during the event, showing the reduced rainfall in southwest China during the 8.2 ka BP period was coupled with Greenland cooling with a possible response rate of 110 ± 30 mm/℃.