Differential Responses Of Stalagmite Oxygen And Carbon Isotope Records To Millennium-scale Events In The Northern And Southern Hemispheres, Hebei Province

Stalagmite is the fourth pillar of palaeoclimate reconstruction besides ice core,loess and ocean because of its accurate dating,and it plays an important role in the study of global climate change.The millennial-scale climate events,which are recorded in ice cores,stalagmites and other carriers,are typical features of climate change during the last glacial period.By exploring the characteristics of climate change during the Last Glacial Age and the driving mechanism of millenial-scale events,it is beneficial to further explore the dynamic mechanism of the evolution of the Asian monsoon and to understand the relationship between the Asian monsoon and the climate change in northern and southern high latitudes.Based on 22 ²³⁰Th ages and 986 groups of oxygen and carbon isotopes(?¹⁸O and?¹³C)with two stalagmites in Huangjin cave of Hebei Province,we reconstruct the climate change sequence of HJ1 stalagmite from 55.5?36.6 ka B.P.and the climate change sequence of HJ3 stalagmite from 44?30.4 ka B.P..The reproducibility test shows that?¹⁸O of the stalagmite in Huangjin cave is not affected by the dynamic fractionation of isotopes during the deposition process,so the?¹⁸O of the stalagmite in Huangjin cave can effectively reflect the climate change.Oxygen and carbon isotope records of HJ1stalagmite show significant millennial-scale fluctuation characteristic within the limit of error and correspond to the DO cycle,but have differences in the event structure characteristics and the beginning of time.The beginning time of DO event of?¹³C records is not later than?¹⁸O record,suggests that?¹⁸O and?¹³C have different response patterns in millennial-scale events.Oxygen and carbon isotopes in stalagmte have great potential to express millennial-scale events.Comparing the?¹⁸O records of HJ1 stalagmite with those of cave stalagmites in different latitudes of Chinese monsoon region,we found that different records have similar millennial-scale fluctuation characteristics.This spatial consistency indicates that the?¹⁸O records of Chinese stalagmites are mainly controlled by the East Asian summer monsoon intensity and the water vapor transport.The?¹⁸O of the stalagmite in Huangjin cave,Hebei Province can indicate the precipitation change of the East Asian summer monsoon,that is,when the East Asian summer monsoon is strengthened(weakened)and the regional precipitation is increased(decreased),the?¹⁸O in HJ1 is negative(positive).By comparing the?¹³C of HJ1 stalagmite with the?¹⁸O of Greenland NGRIP ice core,we found that they have good similarity in millennial-scale events,especially the“zigzag”structure and rapid mutation characteristics.This finding suggests that the northern high latitude climate may directly regulate the water and heat allocation in northern China through the westerly jet,and then affect the overlying vegetation status and soil CO₂ yield in the study area,thereby controlling the?¹³C of stalagmite.By comparing?¹⁸O of HJ1 stalagmite,Greenland NGRIP ice core and Antarctic WDC ice core,we speculate that?¹⁸O record of the Asian monsoon on millennial scale is out of phase with the temperature of the Antarctic ice core record within the limit of error.The teleconnection between East Asian summer monsoon intensity(or precipitation)and the Antarctic temperature may be related to AMOC that controls heat redistribution between hemispheres.By comparing the?¹³C records of HJ1 stalagmite,the CH₄ records of the Antarctic WDC ice core and the?¹⁸O records of the Greenland NGRIP ice core,the results show that the northern high latitude climate may rapidly regulate the temperature changes in the study area through the westerly jet stream,and then affect the regional vegetation and biomass changes indicated by the?¹³C of Huangjin cave.The relationship between the millennial-scale event of the Last Glacial Age in the Asian monsoon and the northern and southern high latitude climatic changes has always been a hot topic in the field of Quaternary palaeoclimate.Due to the structural differences between the polar ice cores and the oxygen isotopic records of Chinese stalagmites in millennial-scale events,the mechanism of teleconnection between high and low latitudes is still unclear.In this paper,we calculate the age difference between initial change points(the initial change point of the transition between glacial and interglacial stages)and midpoint of all DO events in the?¹⁸O records of HJ1 stalagmite,and the average value is about 220 years.We discuss in two different conditions:1.The midpoint for DO12 and DO14 event of?¹³C records of Huangjin cave and NGRIP ice core record predates the midpoint of?¹⁸O records of Huangjin cave by 400 years.In this case,rapid warming of Greenland DO event(midpoint)predates the Antarctic began to grow cold(breakpoint)by200 years,indicates that millennial-scale events during the last glacial age may trigger in northern high latitude,and support the importance of ocean circulation in abrupt change of climate and the signal transmission between the hemispheres.2.The midpoint for DO8-DO11 events of?¹⁸O and?¹³C records in Huangjin cave and in NGRIP ice core?¹⁸O record is synchronous.In this case,the breakpoint of A/AIM event in Antarctic ice core record will predate the Greenland ice core record by around 200 years,which shows that millennial-scale events during the last glacial age or AMOC recovery may trigger in the Southern Ocean.