Variability of summer humidity during the past 800 years on the eastern Tibetan Plateau inferred from δ&lt;sup&gt;18&lt;/sup&gt;O  of tree-ring cellulose

Abstract. We present an 800-year δ18O chronology from the eastern part of the Tibetan Plateau (TP). The chronology dates back to AD 1193 and was sampled in AD 1996 from living Juniperus tibetica trees. This first long-term tree-ring-based δ18O chronology for eastern Tibet provides a reliable archive for hydroclimatic reconstructions. Highly significant correlations were obtained with hydroclimatic variables (relative humidity, vapour pressure, and precipitation) during the summer season. We applied a linear transfer model to reconstruct summer season relative humidity variations over the past 800 years. More moist conditions prevailed during the termination of the Medieval Warm Period while a systematic shift during the Little Ice Age is not detectable. A distinct trend towards more dry conditions since the 1870s is apparent. The moisture decline weakened around the 1950s but still shows a negative trend. The mid-19th century humidity decrease is in good accordance with several multiproxy hydroclimate reconstructions for south Tibet. However, the pronounced summer relative humidity decline is stronger on the central and eastern TP. Furthermore, the relative humidity at our study site is significantly linked to the relative humidity at large parts of the TP. Therefore, we deduce that the reconstructed relative humidity is mostly controlled by local and mesoscale climatic drivers, although significant connections to the higher troposphere of west-central Asia were observed.

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Variability of summer humidity during the past 800 years on the eastern Tibetan Plateau inferred from δ18O of tree-ring cellulose

Climate of the Past Discussions ◽

10.5194/cpd-10-3327-2014 ◽

2014 ◽

Vol 10 (4) ◽

pp. 3327-3356 ◽

Cited By ~ 2

Author(s):

J. Wernicke ◽

J. Grießinger ◽

P. Hochreuther ◽

A. Bräuning

Keyword(s):

Relative Humidity ◽

Tibetan Plateau ◽

19Th Century ◽

Summer Season ◽

Ice Age ◽

Transfer Model ◽

The Tibetan Plateau ◽

Spatial Correlations ◽

The Past ◽

The North

Abstract. We present an 800 years long δ18O chronology from the eastern part of the Tibetan Plateau (TP). The chronology dates back to 1193 AD and was sampled in 1996 AD from living Juniperus tibetica trees. The chronology is unique for eastern Tibet and provides a reliable archive for hydroclimatic reconstructions. Highly significant correlations were obtained with air moisture (relative humidity, vapour pressure and precipitation) during the summer season. We applied a linear transfer model to reconstruct the summer season relative humidity variation over the past 800 years. We identified more moist conditions at the termination of the Medieval Warm Period, an oscillating air humidity around the mean during the Little Ice Age and a sudden decrease of relative humidity since the 1870s. The late 19th century humidity decrease is in good accordance with several multiproxy hydroclimate reconstructions for south Tibet. On the other hand, since the end of the 19th century strong evidences for an increase in humidity on the northern TP is exhibited. Spatial correlation analysis with the North Atlantic Oscillation index (NAO) and the sea surface temperature (SST) of Niño region 3.4 reveal a weak and nonstationary relationship to the δ18O chronology. Instead, spatial correlations expose a dominating convective influence to the relative humidity reconstruction. Furthermore, wavelength analysis reveal good agreements between the significant cyclicities in our δ18O chronology and several moisture sensitive proxy archives.

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A comparison of tree-ring records and glacier variations over the past 700 years, northeastern Tibetan Plateau

Annals of Glaciology ◽

10.3189/172756406781812438 ◽

2006 ◽

Vol 43 ◽

pp. 86-90 ◽

Cited By ~ 24

Author(s):

Xiaohua Gou ◽

Fahu Chen ◽

Meixue Yang ◽

Gordon Jacoby ◽

Jianfeng Peng ◽

...

Keyword(s):

Tibetan Plateau ◽

Tree Ring ◽

Climate Changes ◽

Yellow River ◽

Ice Age ◽

Maximum Temperature ◽

The Yellow River ◽

The Tibetan Plateau ◽

The Past ◽

Summer Maximum

AbstractThe ecological environment of the headwater area of the Yellow River, west China, is seriously deteriorating because of the harsh natural environment, weakened ecological systems and intensified human activities as well as regional climate changes. Forests and glaciers coexist in this area. Glaciers in the area have retreated over the last decade because of climate change. Most glaciers on the Tibetan Plateau (TP) tend to retreat during warm intervals and advance during cold intervals. Tree-ring records provide an important index for examining past climate changes. A total of 139 core samples from 97 living cypresses (Juniperus przewalskii) in the central region of the Yellow River headwater area, the Animaqin mountains, northeastern TP, were sampled from three sites that are close to each other. The chronologies were developed using the ARSTAN program. Analyses indicate that these tree-ring width records reflect the summer maximum temperature of the study area over the past 700 years. The tree-ring records and the glacier advances recorded by terminal moraines are compared. Inferred summer maximum temperatures suggest three cold periods during the Little Ice Age, around AD1500, 1700 and 1850. These cold intervals are consistent with the glacier moraine record from the region.

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Temperature variations over the past millennium on the Tibetan Plateau revealed by four ice cores

Annals of Glaciology ◽

10.3189/172756407782871305 ◽

2007 ◽

Vol 46 ◽

pp. 362-366 ◽

Cited By ~ 14

Author(s):

Tandong Yao ◽

Keqin Duan ◽

L.G. Thompson ◽

Ninglian Wang ◽

Lide Tian ◽

...

Keyword(s):

Tibetan Plateau ◽

19Th Century ◽

Northern Hemisphere ◽

Ice Core ◽

Ice Cores ◽

Ice Age ◽

The Tibetan Plateau ◽

Late 19Th Century ◽

The Past ◽

Northern Tibetan Plateau

AbstractTemperature variation on the Tibetan Plateau over the last 1000 years has been inferred using a composite δ18O record from four ice cores. Data from a new ice core recovered from the Puruogangri ice field in the central Tibetan Plateau are combined with those from three other cores (Dunde, Guliya and Dasuopu) recovered previously. The ice-core δ18O composite record indicates that the temperature change on the whole Tibetan Plateau is similar to that in the Northern Hemisphere on multi-decadal timescales except that there is no decreasing trend from AD 1000 to the late 19th century. The δ18O composite record from the northern Tibetan Plateau, however, indicates a cooling trend from AD 1000 to the late 19th century, which is more consistent with the Northern Hemisphere temperature reconstruction. The δ18O composite record reveals the existence of the Medieval Warm Period and the Little Ice Age (LIA) on the Tibetan Plateau. However, on the Tibetan Plateau the LIA is not the coldest period during the last millennium as in other regions in the Northern Hemisphere. The present study indicates that the 20th-century warming on the Tibetan Plateau is abrupt, and is warmer than at any time during the past 1000 years.

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Climatic variations over the past millennium revealed by tree ring from the Tibetan Plateau

Quaternary International ◽

10.1016/j.quaint.2012.08.249 ◽

2012 ◽

Vol 279-280 ◽

pp. 174

Author(s):

XiaoHua Gou

Keyword(s):

Tibetan Plateau ◽

Tree Ring ◽

The Tibetan Plateau ◽

Climatic Variations ◽

The Past ◽

Past Millennium

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Terrestrial-aquatic ecosystem links on the Tibetan Plateau inferred from sedaDNA shotgun sequencing

10.5194/egusphere-egu21-14881 ◽

2021 ◽

Author(s):

Sisi Liu ◽

Kathleen R. Stoof-Leichsenring ◽

Luise Schulte ◽

Heike H. Zimmermann ◽

Steffen Mischke ◽

...

Keyword(s):

Tibetan Plateau ◽

Species Interactions ◽

Shotgun Sequencing ◽

Ice Age ◽

The Tibetan Plateau ◽

Ecological Communities ◽

Submerged Plants ◽

Ecological Processes ◽

Large Herbivores ◽

The Past

Climate change and associated species interactions are responsible for many vital mechanisms governing the dynamics of ecological communities. However, the long-term contribution of environmental conditions and species connections to community assembly remain mostly unknown. Here, we present changes of terrestrial and freshwater communities based on metagenomic shotgun data retrieved from lacustrine sediments of an alpine freshwater lake on the south-eastern Tibetan Plateau (Hengduan Mountains) covering the past 15,100 thousand years (ka). Terrestrial assemblages between 15.1-14 ka are explained by the harsh environment and facilitative interactions due to diverse cushion plants, while the abundant ice-age algae (Nannochloropsis and N. limnnetica) indicate dominance of glacial meltwaters. A sharp decrease in alpine herbs (e.g Asteraceae, Carex and Poaceae) corresponded to competitive interactions with the colonization of woody plants (Salicaceae, Salix, Rhododendron and R. delavayi) since 14 ka, leading to a decline of large herbivores (Bovidae and Bos mutus) that predominated. Meanwhile, the disappearance of ice-age algae and the expansion of submerged plants (e.g., Potamogeton, P. perfoliatus, Myriophyllum, and M. spicatum) are consistent with an increase in temperature and a plentiful supply of nutrients due to weathering and soil erosion. The loss of submerged plants during the late Holocene (~3.6 ka) is probably related to environmental deterioration; however, it could also be related to the Cyanobacteria boom. Our study highlights that shotgun sequencing of lake sediments is an important tool for exploring ecological processes of communities in the past.

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