Millennial Minimum Temperature Variations in the Qilian Mountains, China: evidence from Tree rings

Abstract. A 1342 yr-long tree-ring chronology was developed from Qilian junipers in the central Qilian Mountains of the north-eastern Tibetan Plateau, China. The climatic implications of this chronology were investigated using simple correlation, partial correlation and response function analyses. The chronology was significantly positively correlated with temperature variables during the pre- and current growing seasons, especially with minimum temperature. The variability of the mean minimum temperature from January to August since 670 AD was then reconstructed based on the tree-ring chronology. The reconstruction explained 58.5% of the variance in the instrumental temperature records during the calibration period (1960–2011) and captured the variation patterns in minimum temperature at the annual to centennial time scales over the past millennium. The most recent 50 yr were the warmest period, while 1690–1880 was the coldest period since 670 AD. Comparisons with other temperature series from neighbouring regions and for the Northern Hemisphere as a whole supported the validity of our reconstruction and suggested that it provided a good regional representation of temperature change in the north-eastern Tibetan Plateau. The results of multi-taper spectral analysis showed the occurrence of significant quasi-periodic behaviour at a number of periods (2–3, 28.8–66.2, 113.6–169.5, and 500 yr), which were consistent with those associated with El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and solar activity. Some reconstructed cold events may have close relationship with the volcanic eruptions.

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Millennial minimum temperature variations in the Qilian Mountains, China: evidence from tree rings

Climate of the Past ◽

10.5194/cp-10-1763-2014 ◽

2014 ◽

Vol 10 (5) ◽

pp. 1763-1778 ◽

Cited By ~ 29

Author(s):

Y. Zhang ◽

X. M. Shao ◽

Z.-Y. Yin ◽

Y. Wang

Keyword(s):

Tibetan Plateau ◽

Tree Ring ◽

Tree Rings ◽

Minimum Temperature ◽

Volcanic Eruptions ◽

Qilian Mountains ◽

Tree Ring Chronology ◽

Northeastern Tibetan Plateau ◽

Reconstructed Temperature ◽

The Impact

Abstract. A 1343-year tree-ring chronology was developed from Qilian junipers in the central Qilian Mountains of the northeastern Tibetan Plateau (TP), China. The climatic implications of this chronology were investigated using simple correlation, partial correlation and response function analyses. The chronology was significantly positively correlated with temperature variables prior to and during the growing season, especially with monthly minimum temperature. Minimum temperature anomalies from January to August since AD 670 were then reconstructed based on the tree-ring chronology. The reconstruction explained 58% of the variance in the instrumental temperature records during the calibration period (1960–2012) and captured the variation patterns in minimum temperature at the annual to centennial timescales over the past millennium. The most recent 50 years were the warmest period, while 1690–1880 was the coldest period since AD 670. Comparisons with other temperature series from neighbouring regions and for the Northern Hemisphere as a whole supported the validity of our reconstruction and suggested that it provided a good regional representation of temperature change in the northeastern Tibetan Plateau. The results of wavelet analysis showed the occurrence of significant quasi-periodic patterns at a number of recurring periods (2–4, 40–50, and 90–170 years), which were consistent with those associated with El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and solar activity. The comparison between the reconstructed temperature and the index of tropical volcanic radiative forcing indicated that some cold events recorded by tree rings may be due to the impact of tropical volcanic eruptions.

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Responses of fluvial terrace formation to monsoon climate changes in the north-eastern Tibetan Plateau: Evidence from pollen and sedimentary records

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2020.110196 ◽

2021 ◽

Vol 564 ◽

pp. 110196

Author(s):

Bingling Wang ◽

Xianyan Wang ◽

Shuangwen Yi ◽

Lin Zhao ◽

Huayu Lu

Keyword(s):

Tibetan Plateau ◽

Climate Changes ◽

Eastern Tibetan Plateau ◽

Monsoon Climate ◽

Fluvial Terrace ◽

Sedimentary Records ◽

The North ◽

North Eastern

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Critical minimum temperature limits xylogenesis and maintains treelines on the Tibetan Plateau

10.1101/093781 ◽

2016 ◽

Author(s):

Xiaoxia Li ◽

Eryuan Liang ◽

Jozica Gricar ◽

Sergio Rossi ◽

Katarina Cufar ◽

...

Keyword(s):

Tibetan Plateau ◽

Tree Ring ◽

Minimum Temperature ◽

The Tibetan Plateau ◽

Climatic Variable ◽

Eastern Tibetan Plateau ◽

Growing Seasons ◽

Tree Ring Data ◽

Xylem Growth ◽

Ecological Mechanisms

ABSTRACTPhysiological and ecological mechanisms that define treelines are still debated. It is suggested that the absence of trees above the treeline is caused by the low temperature that limits growth. Thus, we raise the hypothesis that there is a critical minimum temperature (CTmin) preventing xylogenesis at treeline. We tested this hypothesis by examining weekly xylogenesis across three and four growing seasons in two natural Smith fir (Abies georgei var. smithii) treeline sites on the south-eastern Tibetan Plateau. Despite differences in the timing of cell differentiation among years, minimum air temperature was the dominant climatic variable associated with xylem growth; the critical minimum temperature (CTmin) for the onset and end of xylogenesis occurred at 0.7±0.4 °C. A process-based-modeled chronology of tree-ring formation using this CTmin was consistent with actual tree-ring data. This extremely low CTmin permits Smith fir growing at treeline to complete annual xylem production and maturation and provides both support and a mechanism for treeline formation.

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Cryoconite on a glacier on the north-eastern Tibetan plateau: light-absorbing impurities, albedo and enhanced melting

Journal of Glaciology ◽

10.1017/jog.2019.41 ◽

2019 ◽

Vol 65 (252) ◽

pp. 633-644 ◽

Cited By ~ 3

Author(s):

YANG LI ◽

SHICHANG KANG ◽

FANGPING YAN ◽

JIZU CHEN ◽

KUN WANG ◽

...

Keyword(s):

Tibetan Plateau ◽

Mass Balance ◽

Glacier Mass Balance ◽

Eastern Tibetan Plateau ◽

The North ◽

Ice Surface ◽

Northern Tibetan Plateau ◽

North Eastern ◽

The Mean

ABSTRACTCryoconite is a dark-coloured granular sediment that contains biological and mineralogical components, and it plays a pivotal role in geochemistry, carbon cycling and glacier mass balance. In this work, we collected cryoconite samples from Laohugou Glacier No. 12 (LHG) on the north-eastern Tibetan Plateau during the summer of 2015 and measured the spectral albedo. To explore the impacts of this sediment on surface ablation, the ice melting differences between the cryoconite-free (removed) ice and the intact layers were compared. The results showed that the mean concentrations of black carbon (BC), organic carbon (OC) and total iron (Fe) in the LHG cryoconite were 1.28, 11.18 and 39.94 mg g−1, respectively. BC was found to play a stronger role in solar light adsorption than OC and free Fe. In addition, ice covered by cryoconite exhibited the lowest mean reflectance (i.e., <0.1). Compared with the cryoconite-free ice surface, cryoconite effectively absorbed solar energy and enhanced glacial melting at a rate of 2.27–3.28 cm d−1, and free Fe, BC and OC were estimated to contribute 1.01, 0.99 and 0.76 cm d−1, respectively. This study provides important insights for understanding the role of cryoconite in the glacier mass balance of the northern Tibetan Plateau.

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