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Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 years

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Název: Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 years
Autoři: Hai Cheng, Hai Xu, Yanjun Cai, Lawrence R. Edwards, Yongli Gao, Liangcheng Tan, Haiwei Zhang, Zhisheng An
Zdroj: Earth and Planetary Science Letters. 482:580-590
Informace o vydavateli: Elsevier BV, 2018.
Rok vydání: 2018
Témata: Geochemistry & Geophysics, Science & Technology, CLIMATE-CHANGE, Holocene, ANNUALLY-LAYERED STALAGMITE, TRACE-ELEMENT DISTRIBUTION, Monsoon Precipitation, 15. Life on land, Stalagmite, 01 natural sciences, 6. Clean water, NORTHERN CHINA, Abrupt Events, ASIAN SUMMER MONSOON, 13. Climate action, VEGETATION HISTORY, Physical Sciences, EAST-ASIA, LAST DEGLACIATION, Hanjiang River, ICE-AGE TERMINATIONS, HIGH-RESOLUTION, 0105 earth and related environmental sciences
Popis: The upper Hanjiang River region is the recharge area of the middle route of South-to-North Water Transfer Project. The region is under construction of the Hanjiang-Weihe River Water Transfer Project in China. Monsoon precipitation variations in this region are critical to water resource and security of China. In this study, high-resolution monsoon precipitation variations were reconstructed in the upper Hanjiang River region over the past 6650 years from δ 18 O and δ 13 C records of four stalagmites in Xianglong cave. The long term increasing trend of stalagmite δ 18 O record since the middle Holocene is consistent with other speleothem records from monsoonal China. This trend follows the gradually decreasing Northern Hemisphere summer insolation, which indicates that solar insolation may control the orbital-scale East Asian summer monsoon (EASM) variations. Despite the declined EASM intensity since the middle Holocene, local precipitation may not have decreased remarkably, as revealed by the δ 13 C records. A series of centennial- to decadal-scale cyclicity was observed, with quasi-millennium-, quasi-century-, 57-, 36- and 22-year cycles by removing the long-term trend of stalagmite δ 18 O record. Increased monsoon precipitation during periods of 4390–3800 a BP, 3590–2960 a BP, 2050–1670 a BP and 1110–790 a BP had caused four super-floods in the upper reach of Hanjiang River. Dramatically dry climate existed in this region during the 5.0 ka and 2.8 ka events, coinciding with notable droughts in other regions of monsoonal China. Remarkably intensified and southward Westerly jet, together with weakened summer monsoon, may delay the onset of rainy seasons, resulting in synchronous decreasing of monsoon precipitation in China during the two events. During the 4.2 ka event and the Little Ice Age, the upper Hanjiang River region was wet, which was similar to the climate conditions in central and southern China, but was the opposite of drought observed in northern China. We propose that weakened summer monsoon and less strengthened or normal Westerly jet may cause rain belt stay longer in the southward region, which reduced rainfall in northern China but enhanced it in central and southern China.
Druh dokumentu: Article
Jazyk: English
ISSN: 0012-821X
DOI: 10.1016/j.epsl.2017.11.044
Přístupová URL adresa: https://experts.umn.edu/en/publications/centennial-to-decadal-scale-monsoon-precipitation-variations-in-t
https://www.sciencedirect.com/science/article/pii/S0012821X1730688X
https://ui.adsabs.harvard.edu/abs/2018E&PSL.482..580T/abstract
Rights: Elsevier TDM
Přístupové číslo: edsair.doi.dedup.....3f53f92a4f8ea1f20178d3a8d46b52a1
Databáze: OpenAIRE
Popis
Abstrakt:The upper Hanjiang River region is the recharge area of the middle route of South-to-North Water Transfer Project. The region is under construction of the Hanjiang-Weihe River Water Transfer Project in China. Monsoon precipitation variations in this region are critical to water resource and security of China. In this study, high-resolution monsoon precipitation variations were reconstructed in the upper Hanjiang River region over the past 6650 years from δ 18 O and δ 13 C records of four stalagmites in Xianglong cave. The long term increasing trend of stalagmite δ 18 O record since the middle Holocene is consistent with other speleothem records from monsoonal China. This trend follows the gradually decreasing Northern Hemisphere summer insolation, which indicates that solar insolation may control the orbital-scale East Asian summer monsoon (EASM) variations. Despite the declined EASM intensity since the middle Holocene, local precipitation may not have decreased remarkably, as revealed by the δ 13 C records. A series of centennial- to decadal-scale cyclicity was observed, with quasi-millennium-, quasi-century-, 57-, 36- and 22-year cycles by removing the long-term trend of stalagmite δ 18 O record. Increased monsoon precipitation during periods of 4390–3800 a BP, 3590–2960 a BP, 2050–1670 a BP and 1110–790 a BP had caused four super-floods in the upper reach of Hanjiang River. Dramatically dry climate existed in this region during the 5.0 ka and 2.8 ka events, coinciding with notable droughts in other regions of monsoonal China. Remarkably intensified and southward Westerly jet, together with weakened summer monsoon, may delay the onset of rainy seasons, resulting in synchronous decreasing of monsoon precipitation in China during the two events. During the 4.2 ka event and the Little Ice Age, the upper Hanjiang River region was wet, which was similar to the climate conditions in central and southern China, but was the opposite of drought observed in northern China. We propose that weakened summer monsoon and less strengthened or normal Westerly jet may cause rain belt stay longer in the southward region, which reduced rainfall in northern China but enhanced it in central and southern China.
ISSN:0012821X
DOI:10.1016/j.epsl.2017.11.044