Current Browsing: Paleoclimate Reconstruction


Temperature-sensitive proxy over the Northern Hemisphere during 1000-2000 AD

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for the past millennium over the Northern Hemisphere, including 370 tree rings, 15 ice cores, 9 lake sediments and 2 historical documents; This data is derived from the global temperature proxy dataset released by PAGES2k Consortum in 2017; During the process of temperature assimilation in the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.

2022-10-25

Millennial precipitation datasets over the three poles produced by paleoclimate data assimilation

(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.

2022-08-24

Millennial temperature datasets over the three poles produced by paleoclimate data assimilation

(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.

2022-08-23

Fossil of zooplankton remains, pigment and nutrients in Dagze Co, central Tibet Plateau (1440-2002 A.D.)

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.

2022-04-19

Tree age data sampled from different glacier moraines in the central Himalayas

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.

2022-04-15

2022-04-15

Fossil of zooplankton remains, pigment and nutrients in Dagze Co, central Tibet Plateau (1440-2002 A.D.)

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.

2020-10-25

Age data of the deep sediment core in the midstream of the Heihe River

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.

2020-07-30

Palynological data of vegetation evolution since the formation of Heihe River

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.

2020-07-28

Ages of geomorphic surfaces along the Heihe River (late pleistocene)

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.

2020-07-28