There are 396 temperature-sensitive proxy data for the past millennium over the Northern Hemisphere, including 370 tree rings, 15 ice cores, 9 lake sediments and 2 historical documents; This data is derived from the global temperature proxy dataset released by PAGES2k Consortum in 2017; During the process of temperature assimilation in the past millennium (1000-2000 AD) in the Northern Hemisphere, the data were further screened, and only the data with annual resolution were retained; The proxy data contained in the dataset have passed strict quality inspection and temperature signal verification; The data set can be used to reconstruct the temperature of the Northern Hemisphere at the hemispherical and regional scales for the past millennium.
FANG Miao
(1) Data content: data set of precipitation field of the three poles (Arctic, Antarctic and Qinghai Tibet Plateau) in the past millennium; (2) Data source and processing method: the data is independently produced by the author and is produced by assimilating the precipitation proxy data in the three polar regions through the paleoclimate data assimilation method; (3) Data quality description: there is a high degree of spatial-temporal consistency between the data set and the precipitation data sets measured by multiple instruments (correlation coefficient is above 0.35, P < 0.001; Nash efficiency coefficient is above 0.3). In addition, the correlation coefficient with multiple precipitation data series reconstructed based on proxy data is between 0.2 and 0.6 (P < 0.001); (4) It can be used to study the temporal and spatial changes of precipitation in the past millennium in the three polar regions.
FANG Miao
(1) Data content: Millennial temperature (near-surface air temperature anomaly based on the millinnial mean）datasets over the three poles, e.g., Arctic, Antarctic, and Qinghai-Tibet Plateau; (2) Data sources and processing methods: These datasets were produced by the authors themselves using the paleoclimate data assimilationand approach based on climatic proxies over the three poles; (3) Description of data quality: There are high spatio-temporal consistency between these datasets and several instrumental gridded temperature datasets (correlation coefficient above 0.6, p <0.001; Nash efficiency coefficient above 0.5). In addition, the correlations between these datasets and several proxy-based temperature series are between 0.4 and 0.8 (p <0.001). (4) Data application achievements and prospects: These datasets can be used to investigate the temporal and spatial variations in temperature over the three poles during the past millennium.
FANG Miao
Based on the analysis of brgdgts and hydrogen isotopes of leaf wax in lake sediments from Tengchong Qinghai (tcqh) in Yunnan Province, this study shows for the first time the high-resolution annual average temperature change history of low latitude land since the last glacial period (since the last 88000 years). According to the annual average temperature of South Asia established by tcqh core, there are two warm periods of 88000-71000 years and 45000-22000 years in this region, and the temperature range is about 2-3 ° C. Since the Holocene, the temperature has been increasing for about 1-2 years ° C。
ZHAO Cheng
Relationship between modern pollen and climate, and its representative to vegetation are the important references in explaining and reconstructing past climate and vegetation qualitatively or quantitatively. To extrct past climate and vegetation signals from fossil pollen spectrum of a lacustrine sediment, a corresponding modern pollen dataset collected from lake-sediment surface is necessary. At present, there are a few modern pollen datasets extracted from lake sediment-surface established on the Tibetan Plateau, however, the geographic gaps (e.g. the central and east Tibetan Plateau) of available sampled lakes influence the correct understanding. To ensure the even distribution of the representative lakes, we collected lake sediment-surface samples (n=117) covering the alpine meadow evenly on the east and central Tibetan Plateau, in July and August 2018. For pollen extraction, approximately 10 g (wet original sediment) per sample were sub-sampled. Pollen sample was processed by the standard acid-alkali-acid procedures followed by 7-μm-mesh sieving. More than 500 terrestrial pollen grains were counted for each sample. Pollen assemblages of the dataset from alpine meadow are dominated by Cyperaceae (mean is 68.4%, maximum is 95.9%), with other herbaceous pollen taxa as commen taxa including Poaceae (mean is 10.3%, maximum is 87.7%), Ranunculaceae (mean is 4.8%, maximum is 33.6%), Artemisia (mean is 3.7%, maximum is 24.5%), Asteraceae (mean is 2.1%, maximum is 33.6%), etc. Salix (mean is 0.4%, maximum is 5.3%) is the major shrub taxon in these pollen assemblages, while arboreal taxa occur with low percentages generally (mean of total arboreal percentages is 0.9% (maximum is 5.8%), including mainly Pinus (mean is 0.3%, maximum is 1.8%), Betula (mean is 0.1%, maximum is 0.9%) and Alnus (mean is 0.1%, maximum is 0.7%). These pollen assemblages represent the plant components well in the alpine meadow communities, although they are influenced slightly by long-distance pollen grain transported by wind or river (such as these arboreal pollen taxa). Together with pollen counts and percentages, we also provided the modern climatic data for the sampled lakes. The China Meteorological Forcing Dataset (CMFD; gridded near-surface meteorological dataset) with a temporal resolution of three hours and a spatial resolution of 0.1° was employed, and the climatic data of the nearest pixel of one sampled lake was defined to represent climatic conditions of the lake. Finally, the mean annual precipitation (Pann), mean annual temperature (Tann) and mean temperature of the coldest month (Mtco) and warmest month (Mtwa) are calculated for each sampled lake.
CAO Xianyong, TIAN Fang, LI Kai, NI Jian
This is Northern Hemispheric (NH) annual near-surface temperature dataset during the past millennium with a 2° spatial resolution, which is produced using the paleoclimate data assimilation approach with EnSRF method, MPI-ESM-P model and 396 multi-proxies from the PAGES2k Consoritum. This dataset agrees well with several observational temperature datasets during the instrumental period, and has a similar level of reliability as the Twentieth Century Reanalysis which assimilates surface pressure observations. In addition, the dataset shows a high level of agreement with previous proxy-based reconstructions (average correlation of annual mean NH temperatures is r = 0.61). The dataset can be used to study the temperature variability over the NH and some regions of the NH during the past millennium (1000-2000 AD).
FANG Miao, LI Xin, CHEN Hans , CHEN Deliang
Paleoecological and paleolimnological studies can provide a long-term perspective on changes in environmental and ecosystem processes. The sediments documented both direct and indirect impacts of climate change and human activities on aquatic ecosystems. The fossils of zooplankton remain and pigments in lake sediments can reflect community structure changes of primary producers and primary consumers. The authors reconstructed the zooplankton and algal community changes during the past 600 years using carapaces of A. tibetiana and resting eggs of D. tibetana and pigments from the sediments of Dagze Co, in the central Tibet Plateau. Using total nitrogen and total phosphorus reconstructed the nutrient changes. These results suggest that algal community structure and changes in production can be attributed to alterations in the zooplankton community, with important implications for Tibetan aquatic ecosystems.
LIANG Jie LIANG Jie
Paleoecological and paleolimnological studies can provide a long-term perspective on changes in environmental and ecosystem processes. The sediments documented both direct and indirect impacts of climate change and human activities on aquatic ecosystems. The fossils of zooplankton remain and pigments in lake sediments can reflect community structure changes of primary producers and primary consumers. The authors reconstructed the zooplankton and algal community changes during the past 600 years using carapaces of A. tibetiana and resting eggs of D. tibetana and pigments from the sediments of Dagze Co, in the central Tibet Plateau. Using total nitrogen and total phosphorus reconstructed the nutrient changes. These results suggest that algal community structure and changes in production can be attributed to alterations in the zooplankton community, with important implications for Tibetan aquatic ecosystems.
LIANG Jie LIANG Jie
Data set contains tree age of trees growing at different glacier moraines in the central Himalayas. The data were obtained using tree ring samples. Cores samples were collected (almost near to the ground level to estimate the minimum age of the related moraine) using an increment borer. Samples were processed by using standard dendrochronological techniques.
SIGDEL Shalik Ram, ZHNAG Hui, ZHU Haifeng, SHER Muhammad, LIANG Eryuan
Based on the study of the terrace formation age in the upper reaches of heihe river, photoluminescence samples were collected from the sediments of grade 6 river terrace near the upper reaches of qilian river.The quartz particles (38-63 microns) in the sample were isolated in the laboratory, the equivalent dose and dose rate in the quartz particles were measured, and the photoluminescence age of the sample was finally obtained.The obtained ages range from 5ka to 82ka, corresponding to the years of cutting down the terraces of all levels.
PAN Baotian, HU Xiaofei
Since the formation of Heihe River, sporopollen data samples have been collected from the drilling strata of Da'ao well in the middle reaches of Heihe River. Drilling location: 39.491 n, 99.605 E. The drilling depth is 140 meters. 128 samples of sporopollen are collected from top to bottom. At present, there are 19 data of sporopollen results, which are distributed in each sedimentary facies from top to bottom. The sporopollen samples were removed from carbonate, organic matter, silicate and other impurities in the laboratory, and the species and data of sporopollen were identified under the microscope. Sporopollen results mainly include the percentage content and number of trees, shrubs, herbs, aquatic, ferns and other families and genera.
HU Xiaofei, PAN Baotian
This data set contains a deep drilling paleomagnetic age data near the open sea in the middle reaches of Heihe River. The borehole is located at 99.432 E and 39.463 n with a depth of 550m. The samples of paleomagnetic age were taken at the interval of 10-50 cm. The paleomagnetic test was carried out in the Key Laboratory of Western Ministry of environmental education of Lanzhou University. The primary remanence of the samples was obtained by alternating demagnetization and thermal demagnetization, and the whole formation magnetic formation was obtained by using the primary remanence direction of each sample, and then the sedimentary age of the strata was obtained by comparing with the standard polarity column. The results show that the bottom boundary of the borehole is about 7 Ma and the top boundary is 0 ma.
HU Xiaofei, PAN Baotian
Since the formation of heihe, palynology data samples were collected from the borehole formation of dasunken well in the middle reaches of heihe.Borehole location: 39.491 n, 99.605 e.The borehole has a depth of 140 meters and 18 palynological samples are collected from top to bottom. Currently, there are 3 palynological results, which are distributed in each sedimentary phase from top to bottom.Impurities such as carbonate, organic matter and silicate were removed from palynology samples in the laboratory, and the palynology types and data were identified under the microscope.Palynology results mainly included the percentage and number of trees, shrubs, herbs, aquatic and ferns.
PAN Baotian, HU Xiaofei
The modern sporopollen identification results of five different geomorphic types in the middle reaches of Heihe River show that there are 39 sporopollen types, 22 main types, belonging to 6 different vegetation types in 45 topsoil samples distributed in the desert vegetation belt. The SPOROPOLLEN ASSEMBLAGES with high percentage of sporopollen in the sporopollen map were selected to represent different geomorphic types. It was found that five geomorphic types (dune, alluvial proluvial fan, flood plain, riverbed and wetland) could be expressed by different combinations of nine sporopollen.
HU Xiaofei, PAN Baotian
In this dataset samples were obtained from groundwater outcrop points and surface water points through the field hydrogeological survey of mabongshan, and the analysis data of deuterium - oxygen - 18 and tritium were obtained by sending them to the laboratory with relevant qualification. This dataset can obtain the isotopic information of groundwater and surface water in the research area of the project, and provide data reference for the water circulation law in the research area.
GUO Yonghai
Natural changes and human impacts of typical karst environments in historical periods: stalagmite recording project is a major research program of "Environmental and Ecological Science in Western China" sponsored by the National Natural Science Foundation of China. The person in charge is Tan Ming, a researcher at the Institute of Geology and Geophysics, Chinese Academy of Sciences. The project runs from January 2002 to December 2009. The temperature data of Beijing hot months (May, June, July and August) in 2650 (665 B.C.-A.D. 1985) are the results of the project. The data are reconstructed according to the correlation between the annual thickness of stalagmites in Shihua Cave in Beijing and meteorological observation data. The temperature signals reflected by soil carbon dioxide and cave dripping are amplified by the soil-organic matter-carbon dioxide system and recorded by the annual sequence of stalagmites. Although the general trend of temperature has decreased in recent thousands of years, the reconstructed temperature reveals that the climate has experienced repeated rapid warming on a century scale. This result is related to other records in the northern hemisphere, indicating that there is a hemispheric influence on the periodic changes of temperature in the sub-millennium scale. The data contains a txt file with attribute fields such as yr.AD, layer number, original thickness (um), maximum error in um (+-), sedimentary trend, detrended thickness (um), reconstructed temperature, maximum error in degree C (+ -), temperature anomaly, temperature anomaly + error, temperature anomaly-error, maximum error in age (yr. +-).
TAN Ming, ZHANG Hucai, LI Tieying
The project studying the evolution pattern and development trend of the arid environment in western China was a major research component of the project Environmental and Ecological Science for West China, which was funded by the National Natural Science Foundation of China. The leading executive of the project was Academician Zhisheng An from the Institute of Earth Environment of the Chinese Academy of Sciences. The project ran from January 2002 to December 2004. The data collected by the project include the following: 1. History and variability data for arid regions in western China: 1) Chinese Loess Plateau mass accumulation rate data (3600-0 kyr BP): Fields include age and mass accumulation rate (MAR) (txt file). 2) Chinese Loess Plateau grain size and magnetic susceptibility data (3600-0 kyr BP): Fields include age, stacked mean grain size, and stacked magnetic susceptibility (txt file). 2. Sporopollen content data of different loess strata since 12 kyr BP in the Yaozhou District of Shanxi Province (excel table): The distributions of 27 species of sporopollen (0-397 cm) from 67 different layers of loess samples are included. 3. 10Be record data (table) 10Be concentration, magnetic susceptibility and bulk density data of loess with different thicknesses (79.67- 0.09 kyr BP). 4. Simulation data on the modulation of the East Asian monsoon resulting from orbital variability driven by the uplift of the Tibetan Plateau: ah0-sum.nc nc file, hh0-sum.nc nc file, jfh0-sum.nc nc file, kdh0-sum.nc nc file, lfh0-sum.nc nc file, mask.nc nc file, phis.nc nc file.
AN Zhisheng
The research area is located in the middle section o the northern slope of the Tianshan Mountains. The research area extends from Wusu in the Tacheng District of Xinjiang in the west to Mulei County in Changji Prefecture in the east. It is approximately 500 km long from east to west. The vertical vegetation gradient on the northern slope of the Tianshan Mountains can be divided into six different belts: alpine cushion vegetation belt (>3400 m), sub-alpine meadow belt (3400~2700 m), mid-mountain forest belt (2700~1720 m), forest steppe belt (1720~1300 m), semi-desert belt (1300~700 m) and typical desert belt (<700 m). Based on the characteristics of the vertical vegetation belts on the northern slope of the Tianshan Mountains, five sedimentary sections with different elevations, different vegetation belts and different sedimentary ages were selected for analysis. Five mid-late Holocene sections were measured to calculate the composite dissimilarity index of sporopollen, and the index was used to explain the sporopollen diversity. The index was then combined with integrated multiple analysis data, such as particle size, magnetic susceptibility, and ignition loss, and the changes in biodiversity and environmental characteristics since the mid-late Holocene in the area were assessed. The data include the following: 1. Sporopollen grain number data for the Daxigou section (8-110 cm, a total of 52 layers were analysed for sporopollen grain number, 3640±60 a BP to 890±60 a BP) 2. Sporopollen grain number data for the Xiaoxigou section (0-90 cm, a total of 38 layers were analysed for sporopollen grain number, 3240±60 a BP) 3. Sporopollen grain number data for the Huashuwozi section (0-106 cm, a total of 52 layers were analysed for sporopollen grain number, 2170±185 a BP to 450±155 a BP) 4. Sporopollen grain number data for the Sichanghu section (10-84 cm, a total of 19 layers were analysed for sporopollen grain number, 1000±50 a BP to 665±65 a BP) 5. Sporopollen grain number data for the Dongdaohaizi section (0-190 cm, a total of 64 layers were analysed for sporopollen grain number, 4500±310 a BP to 305±130 a BP) For detailed descriptions of the data, please refer to the following study: "Palaeo-biodiversity at the Northern Piedmont of Tianshan Mountains in Xinjiang During the Middle to Late Holocene"
NI Jian
The application of general circulation models (GCMs) can improve our understanding of climate forcing. In addition, longer climate records and a wider range of climate states can help assess the ability of the models to simulate climate differences from the present. First, we try to find a substitute index that combines the effects of temperature in different seasons and then combine it with the Beijing stalagmite layer sequence and the Qilian tree-ring sequence to carry out a large-scale temperature reconstruction of China over the past millennium. We then compare the results with the simulated temperature record based on a GCM and ECH-G for the past millennium. Based on the 31-year average, the correlation coefficient between the simulated and reconstructed temperature records was 0.61 (with P < 0.01). The asymmetric V-type low-frequency variation revealed by the combination of the substitute index and the simulation series is the main long-term model of China's millennium-scale temperature. Therefore, solar irradiance and greenhouse gases can account for most of the low-frequency variation. To preserve low-frequency information, conservative detrended methods were used to eliminate age-related growth trends in the experiment. Each tree-ring series has a negative exponential curve installed while retaining all changes. The four fields of the combined 1000-yr (1000 AD-2000 AD) reconstructed temperature records derived from stalagmite and tree-ring archives (excel table) are as follows: 1) Year 2) Annual average temperature reconstruction 3) Reconstructed temperature deviation 4) Simulated temperature deviation
TAN Ming
Data of the project: 1. Sample DOC information sheet: liangfeng cave, qixing cave, general cave, rhinoceros cave 2003-2004 water sample DOC data. Excel sheet 2. Excel sheet of hydrogen and oxygen isotope information of samples: secondary chemical sediments, water/vSMOW, rain 18OvSMOW and so on in liangfeng cave, seven-star cave, general cave, rhino cave 3. The sample water chemical information table of Excel table: header is as follows: sample number # T ℃ pH K + Na + (mg/l) (mg/l) Ca2 + (mg/l) magnesium 2 + (mg/l) Cl - (mg/l) SO42 - (mg/l) HCO3 - (mg/l) SIC SID SIG PPCO2 (ATM) PCO2 (Pa) error 4. Sample carbon isotope information sheet In addition, the project is accompanied by basic information and data information documents.
WANG Shijie
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