Late Holocene monsoon precipitation changes in southern China and their linkage to Northern Hemisphere temperature. (15th March 2020)

• Record Type: Journal Article
• Authors: Zhao, Kan; Wang, Yongjin; Edwards, R. Lawrence; Cheng, Hai; Kong, Xinggong; Liu, Dianbing; Shao, Qingfeng; Cui, Yingfang; Huang, Changchun; Ning, Youfeng; Yang, Xunlin
• Is Part Of: Quaternary science reviews. Volume 232(2020)
• Publication Date: 2020-03-15
• Subjects: Speleothem -- Monsoon precipitation -- Temperature -- Spatial pattern -- Southern China; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2020.106191
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: Observations and models suggest a latitudinal redistribution of precipitation as a result of ongoing global climatic warming. However, the dynamic link between temperature and regional precipitation in the course of natural climatic variability during the current interglacial period remains unclear, especially in the monsoon regions of China. Here we present a reconstruction of a ∼5 year-resolution summer monsoon rainfall record for the past 3200 years, based on 622 pairs of δ 18 O and δ 13 C and 29 230 Th dates from a stalagmite (Wu37) from Wulu Cave in southern China. A close similarity between the δ 18 O and δ 13 C records on centennial to decadal timescales suggests that calcite δ 18 O is most likely a proxy associated with monsoon precipitation. The record reveals that the Little Ice Age (650 - 100 yr B.P.) was a relatively humid period, with two centennial-scale wet events, compared with the Medieval Warm Period (1050 - 650 yr B.P.). In contrast with previous observations in India and northern China, monsoon precipitation variations indicated by our record and other cave records nearby were inversely related to changes in Northern Hemisphere (NH) temperature over the past two millennia, in particular to variations in the thermal gradient between the Northern and Southern hemispheres. This suggests that NH temperature has an important influence on summer precipitation in southern China, via the interhemispheric thermal gradient and land-ocean thermal contrast. In addition, we find that variations of monsoon rainfall in southern China on multi-centennial to centennial timescales are inversely correlated with observed rainfall in the core monsoon region of India and in the northern fringe of the Asian summer monsoon region in China. This spatial pattern of rainfall variability can be interpreted as a result of the migration of the intertropical convergence zone that is likely dominated by the interhemispheric thermal gradient via cross-equatorial airflows. Highlights: Increase of monsoon precipitation in southern China (SC) since the LIA. Anti-phase relationship between SC precipitation and NH temperature. A negative correlation between precipitation in SC and India, northern China. A direct control of NH temperature on the shifts of the ITCZ rainbelt.