Objective Although extensive lakes and eolian sands within and surrounding the Hunshandake Sandy Land(HSL)are sensitive to paleoenvironmental variations in arid and semi-arid eastern Inner Mongolia(e.g.,Yang et al.,20...Objective Although extensive lakes and eolian sands within and surrounding the Hunshandake Sandy Land(HSL)are sensitive to paleoenvironmental variations in arid and semi-arid eastern Inner Mongolia(e.g.,Yang et al.,2013),these records are commonly confined to the last deglaciation,hampering a complete understanding of展开更多
China is distinguished by a prominent monsoonal climate in the east of the country, a continental arid climate in the northwest and a highland cold climate on the Qinghai-Tibet Plateau. Because of the long history of ...China is distinguished by a prominent monsoonal climate in the east of the country, a continental arid climate in the northwest and a highland cold climate on the Qinghai-Tibet Plateau. Because of the long history of Chinese civilization, there are abundant and well-dated documentary records for climate variation over the whole of the country as well as many natural archives（e.g., tree-rings, ice cores, stalagmites, varved lake sediments and corals） that enable high-resolution paleoclimatic reconstruction. In this paper, we review recent advances in the reconstruction of climate and extreme events over the last 2000 years in China. In the last 10 years, many new reconstructions, based on multi-proxies with wide spatial coverage, have been published in China. These reconstructions enable us to understand the characteristics of climate change across the country as well as the uncertainties of regional reconstructions. Synthesized reconstructed temperature results show that warm intervals over the last 2000 years occurred in AD 1–200, AD 551–760, AD 951–1320, and after AD 1921, and also show that cold intervals were in AD 201–350, AD 441–530, AD 781–950, and AD 1321–1920. Extreme cold winters, seen between 1500 and 1900, were more frequent than those after 1950. The intensity of regional heat waves, in the context of recent global warming, may not in fact exceed natural climate variability seen over the last 2000 years. In the eastern monsoonal region of China, decadal, multi-decadal and centennial oscillations are seen in rainfall variability. While the ensemble mean for drought/flood spatial patterns across all cold periods shows a meridional distribution, there is a tri-pole pattern with respect to droughts south of 25°N, floods between 25° and 30°N, and droughts north of 30°N for all warm periods. Data show that extreme drought events were most frequent in the periods AD 301–400, AD 751–800, AD 1051–1150, AD 1501–1550, and AD 1601–1650, while extreme flood events were frequent in the periods AD 101–150, AD 251–300, AD 951–1000, AD 1701–1750, AD 1801–1850, and AD 1901–1950. Between AD 1551–1600, extreme droughts and flood events occurred frequently. In arid northwest China, climate was characterized by dry conditions in AD 1000–1350, wet conditions in AD 1500–1850, and has tended to be wet over recent decades. On the northeastern Qinghai-Tibet Plateau, centennial-scale oscillations in precipitation have occurred over the last 1000 years, interrupted by several multidecadal-scale severe drought events. Of these, the most severe were in the 1480 s and 1710 s. In southwest China, extreme droughts as severe as those seen in Sichuan and Chongqing in 2006 are known to have occurred during historical times.展开更多
Quantitative paleoclimatic reconstruction is crucial for understanding the operation and evolution of the global climate system.For example,a quantitative paleoclimatic reconstruction for the Last Glacial Maximum(18&#...Quantitative paleoclimatic reconstruction is crucial for understanding the operation and evolution of the global climate system.For example,a quantitative paleoclimatic reconstruction for the Last Glacial Maximum(18±2 ka14C,LGM)is fundamental to understanding the evolution of Earth’s climate during the last glacial-interglacial cycle.Previous quantitative palaeoclimate reconstructions in China are generally based on statistical comparison of modern pollen assemblages and modern climate data.These methods are based on the premise that vegetation-climate interactions remain the same through time,and implicitly assume that the interactions are independent of changes in seasonality and atmospheric CO2concentration.However,these assumptions may not always be valid,which may affect the reconstructions.Here,we present the results of a quantitative study of the LGM climate of China based on an improved inverse vegetation model which incorporates physiological processes combined with a new China Quaternary Pollen Database.The results indicate that during the LGM,mean annual temperature(ANNT),mean temperature of the coldest month(MTCO)and mean temperature of the warmest month in China were lower by^5.6±0.8,~11.0±1.6 and^2.6±0.9°C,respectively,compared to today,and that the changes in ANNT were mainly due to the decrease of MTCO.The ANNT decrease in southern China was^5.5±0.5°C.Mean annual precipitation was lower by^46.3±17.8 mm compared to today and was especially low in northern China(~51.2±21.4 mm)due to the decrease in summer rainfall.Comparison of our results with recent outputs from paleoclimatic modelling reveals that while the latter are broadly consistent with our estimated changes in mean annual climatic parameters,there are substantial differences in the seasonal climatic parameters.Our results highlight the crucial importance of developing seasonal simulation on paleoclimatic models,as well as the need to improve the quality of paleoclimatic reconstructions based on proxy records from geological archives.展开更多
Based on cross-dating tree ring age from Tianmu Mountain, Zhejiang Province, theδD of each tree ring nitrocellulose was measured and then theδ D annual time series was established. Using meteorological data from Ti...Based on cross-dating tree ring age from Tianmu Mountain, Zhejiang Province, theδD of each tree ring nitrocellulose was measured and then theδ D annual time series was established. Using meteorological data from Tianmu Mountain Observatory, the responds ofδ D of tree ring to climatic factors were analyzed. The results suggest that theδ D time series of the tree ring correlates well with climatic conditions, primarily with precipitation of the second half of each year, average annual air temperature and average annual maximum air temperature. The reconstructed maximum winter air temperature by theδ D of tree ring is in good correlation with local instrumental data. The low-frequency variations of reconstructed mean maximum air temperature of the winter in Tianmu Mountain corroborate with the temperature change in a large special scale. Tianmu Mountain is located in winter monsoon sensitive zone, thus the influence of winter temperature on tree growth is quite obvious. The results in this paper suggest thatδ D of tree ring is an effective proxy for winter temperature in non-limited regions.展开更多
基金supported by the China Geological Survey (grant no. 121201104000150009)the NSFC (grant no. 41672178)
文摘Objective Although extensive lakes and eolian sands within and surrounding the Hunshandake Sandy Land(HSL)are sensitive to paleoenvironmental variations in arid and semi-arid eastern Inner Mongolia(e.g.,Yang et al.,2013),these records are commonly confined to the last deglaciation,hampering a complete understanding of
基金Basic Research Project of the Ministry of Science and Technology,No.2011FY120300The "Strategic Priority Research Program" of the Chinese Academy of Sciences,No.XDA05080100Research Project from NSFC,No.41430528
文摘China is distinguished by a prominent monsoonal climate in the east of the country, a continental arid climate in the northwest and a highland cold climate on the Qinghai-Tibet Plateau. Because of the long history of Chinese civilization, there are abundant and well-dated documentary records for climate variation over the whole of the country as well as many natural archives（e.g., tree-rings, ice cores, stalagmites, varved lake sediments and corals） that enable high-resolution paleoclimatic reconstruction. In this paper, we review recent advances in the reconstruction of climate and extreme events over the last 2000 years in China. In the last 10 years, many new reconstructions, based on multi-proxies with wide spatial coverage, have been published in China. These reconstructions enable us to understand the characteristics of climate change across the country as well as the uncertainties of regional reconstructions. Synthesized reconstructed temperature results show that warm intervals over the last 2000 years occurred in AD 1–200, AD 551–760, AD 951–1320, and after AD 1921, and also show that cold intervals were in AD 201–350, AD 441–530, AD 781–950, and AD 1321–1920. Extreme cold winters, seen between 1500 and 1900, were more frequent than those after 1950. The intensity of regional heat waves, in the context of recent global warming, may not in fact exceed natural climate variability seen over the last 2000 years. In the eastern monsoonal region of China, decadal, multi-decadal and centennial oscillations are seen in rainfall variability. While the ensemble mean for drought/flood spatial patterns across all cold periods shows a meridional distribution, there is a tri-pole pattern with respect to droughts south of 25°N, floods between 25° and 30°N, and droughts north of 30°N for all warm periods. Data show that extreme drought events were most frequent in the periods AD 301–400, AD 751–800, AD 1051–1150, AD 1501–1550, and AD 1601–1650, while extreme flood events were frequent in the periods AD 101–150, AD 251–300, AD 951–1000, AD 1701–1750, AD 1801–1850, and AD 1901–1950. Between AD 1551–1600, extreme droughts and flood events occurred frequently. In arid northwest China, climate was characterized by dry conditions in AD 1000–1350, wet conditions in AD 1500–1850, and has tended to be wet over recent decades. On the northeastern Qinghai-Tibet Plateau, centennial-scale oscillations in precipitation have occurred over the last 1000 years, interrupted by several multidecadal-scale severe drought events. Of these, the most severe were in the 1480 s and 1710 s. In southwest China, extreme droughts as severe as those seen in Sichuan and Chongqing in 2006 are known to have occurred during historical times.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA13010106)the National Key Research and Development Program of China (Grant No. 2016YFA0600504)+1 种基金the National Natural Science Foundation of China (Grant Nos. 41572165, 41430531, 41125011 & 41472319)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05120700)
文摘Quantitative paleoclimatic reconstruction is crucial for understanding the operation and evolution of the global climate system.For example,a quantitative paleoclimatic reconstruction for the Last Glacial Maximum(18±2 ka14C,LGM)is fundamental to understanding the evolution of Earth’s climate during the last glacial-interglacial cycle.Previous quantitative palaeoclimate reconstructions in China are generally based on statistical comparison of modern pollen assemblages and modern climate data.These methods are based on the premise that vegetation-climate interactions remain the same through time,and implicitly assume that the interactions are independent of changes in seasonality and atmospheric CO2concentration.However,these assumptions may not always be valid,which may affect the reconstructions.Here,we present the results of a quantitative study of the LGM climate of China based on an improved inverse vegetation model which incorporates physiological processes combined with a new China Quaternary Pollen Database.The results indicate that during the LGM,mean annual temperature(ANNT),mean temperature of the coldest month(MTCO)and mean temperature of the warmest month in China were lower by^5.6±0.8,~11.0±1.6 and^2.6±0.9°C,respectively,compared to today,and that the changes in ANNT were mainly due to the decrease of MTCO.The ANNT decrease in southern China was^5.5±0.5°C.Mean annual precipitation was lower by^46.3±17.8 mm compared to today and was especially low in northern China(~51.2±21.4 mm)due to the decrease in summer rainfall.Comparison of our results with recent outputs from paleoclimatic modelling reveals that while the latter are broadly consistent with our estimated changes in mean annual climatic parameters,there are substantial differences in the seasonal climatic parameters.Our results highlight the crucial importance of developing seasonal simulation on paleoclimatic models,as well as the need to improve the quality of paleoclimatic reconstructions based on proxy records from geological archives.
基金the National Natural Science Foundation of China (Grant 49771001).
文摘Based on cross-dating tree ring age from Tianmu Mountain, Zhejiang Province, theδD of each tree ring nitrocellulose was measured and then theδ D annual time series was established. Using meteorological data from Tianmu Mountain Observatory, the responds ofδ D of tree ring to climatic factors were analyzed. The results suggest that theδ D time series of the tree ring correlates well with climatic conditions, primarily with precipitation of the second half of each year, average annual air temperature and average annual maximum air temperature. The reconstructed maximum winter air temperature by theδ D of tree ring is in good correlation with local instrumental data. The low-frequency variations of reconstructed mean maximum air temperature of the winter in Tianmu Mountain corroborate with the temperature change in a large special scale. Tianmu Mountain is located in winter monsoon sensitive zone, thus the influence of winter temperature on tree growth is quite obvious. The results in this paper suggest thatδ D of tree ring is an effective proxy for winter temperature in non-limited regions.
