Xianglong Cave, China 6,650 year Speleothem Stable Isotope Data Tan, L.; Cai, Y.; Cheng, H.; Edwards, R.L.; Gao, Y.; Xu, H.; Zhang, H.; An, Z. Tan, L. Cai, Y. Cheng, H. Edwards, R.L. Gao, Y. Xu, H. Zhang, H. An, Z. earth science/paleoclimate/speleothems (delta 18O,calcium carbonate,null,per mil VPDB,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (delta 13C,calcium carbonate,null,per mil VPDB,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (sample identification,null,null,null,null,speleothems,null,null,C,StalagmiteID) earth science/paleoclimate/speleothems (age,null,null,calendar year before present,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (growth rate,calcium carbonate,null,millimeter per year,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems earth science/paleoclimate/speleothems (Xianglong Cave>LATITUDE 32.9975>LONGITUDE 106.3281) 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 d18O and d13C records of four stalagmites in Xianglong cave. The long term increasing trend of stalagmite d18O 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 d13C 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 d18O 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. STUDY NOTES: Speleothem oxygen and carbon isotope records from Xianglong Cave, upper Hanjiang River region over the last 6650 years NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Tan, L. Investigator : Cai, Y. Investigator : Cheng, H. Investigator : Edwards, R.L. Investigator : Gao, Y. Investigator : Xu, H. Investigator : Zhang, H. Investigator : An, Z. 2018-04-12 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23870 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xianglong2018.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xianglong2018.txt English https://www.ncdc.noaa.gov/paleo/study/23870 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xianglong2018.txt Liangcheng Tan, Yanjun Cai, Hai Cheng, R. Lawrence Edwards, Yongli Gao, Hai Xu, Haiwei Zhang, Zhisheng An2018Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 yearsEarth and Planetary Science Letters482580-59010.1016/j.epsl.2017.11.044https://www.sciencedirect.com/science/article/pii/S0012821X1730688X START YEAR: 6651 cal yr BP * END YEAR: 653 cal yr BP 106.3281 32.9975 106.3281 32.9975