Variations of water stable isotopes (δ18O) in two lake basins, southern Tibetan Plateau

Abstractδ18O measurements based on systematic sampling and isotopic modeling have been adopted to study the controls of stable isotopes in lake water in two lake basins (lakes Yamdrok-tso and Puma Yum-tso) at two different elevations on the southern Tibetan Plateau. Temporally, δ18O values in precipitation and lake water display a seasonal fluctuation in both lakes. Spatially, δ18O values in the two lake basins increase by 10% from the termini of glaciers to the lake shores, by ∽1% from the lake shores to the lake center and by 0.4% from the water surface to depth in these lakes. The clear annual δ18O variations indicate that lake water mixes sufficiently in a short time. Model results show that glacial meltwater and surface lake-water temperature are not the dominant factors in the balance process of stable isotopes in lake water. Equilibrium δ18O values decrease by 0.8% for Yamdrok-tso lake and 0.6% for Puma Yum-tso lake when glacial meltwater contributions to these lakes shrink by 60%. δ18O ratios increase rapidly during the initial stages and take a longer time to approach the equilibrium value.

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Evaporative enrichment of stable isotopes (δ18O and δD) in lake water and the relation to lake-level change of Lake Qinghai, Northeast Tibetan Plateau of China

Journal of Arid Land ◽

10.1007/s40333-015-0048-6 ◽

2015 ◽

Vol 7 (5) ◽

pp. 623-635 ◽

Cited By ~ 20

Author(s):

Huawu Wu ◽

Xiaoyan Li ◽

Jing Li ◽

Zhiyun Jiang ◽

Guangyong Li ◽

...

Keyword(s):

Stable Isotopes ◽

Tibetan Plateau ◽

Lake Water ◽

Lake Level ◽

Lake Qinghai ◽

Lake Level Change ◽

Level Change ◽

Evaporative Enrichment ◽

Δ18o And Δd

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Isotopic variation in the lake water balance at the Yamdruk-tso basin, southern Tibetan Plateau

Hydrological Processes ◽

10.1002/hyp.6919 ◽

2008 ◽

Vol 22 (17) ◽

pp. 3386-3392 ◽

Cited By ~ 32

Author(s):

Lide Tian ◽

Zhongfang Liu ◽

Tongliang Gong ◽

Changliang Yin ◽

Wusheng Yu ◽

...

Keyword(s):

Tibetan Plateau ◽

Water Balance ◽

Lake Water ◽

Isotopic Variation ◽

Southern Tibetan Plateau ◽

Lake Water Balance

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ENSO Effects on Annual Variations of Summer Precipitation Stable Isotopes in Lhasa, Southern Tibetan Plateau

Journal of Climate ◽

10.1175/jcli-d-16-0868.1 ◽

2018 ◽

Vol 31 (3) ◽

pp. 1173-1182 ◽

Cited By ~ 13

Author(s):

Jing Gao ◽

You He ◽

Valerie Masson-Delmotte ◽

Tandong Yao

Keyword(s):

Stable Isotopes ◽

Tibetan Plateau ◽

Isotopic Composition ◽

Southern Oscillation ◽

La Niña ◽

Annual Variations ◽

La Nina ◽

Stable Isotopic Composition ◽

Stable Isotopic ◽

Southern Tibetan Plateau

Abstract Although El Niño–Southern Oscillation (ENSO) influences the Indian summer monsoon, its impact on moisture transport toward the southern Tibetan Plateau (TP) remains poorly understood. Precipitation stable isotopes are useful indices for climate change in the TP. Classical interpretations of variations of precipitation stable isotopes focus on the local surface air temperature or precipitation amount. However, several of the latest studies suggested they may correlate with large-scale modes of variability, such as ENSO. This paper presents a detailed study of ENSO’s effect on annual variations of the oxygen stable isotopic composition of precipitation (δ18Op) at Lhasa in the southern TP for up to 10 years. The stable isotopic composition of water vapor from satellite data [Tropospheric Emission Spectrometer (TES)] and simulations from an isotopically enabled atmospheric general circulation model (zoomed LMDZiso) are used to explore the mechanism that leads to variations of δ18Op at Lhasa. Statistically significant correlations between δ18Op and ENSO indices [Southern Oscillation index (SOI) and Niño-3.4 sea surface temperature index (Niño-3.4)] are observed. This paper shows that ENSO’s effects on the location and intensity of convection over the Arabian Sea, the Bay of Bengal, and the tropical Indian Ocean, along moisture transport paths toward Lhasa, further impact convection from the northern Tibetan Plateau. The changing of this convection results in lower δ18Op at Lhasa in 2007, a La Niña year, and higher δ18Op in 2006, an El Niño year. The study presented here confirms that the regional upstream convection related to ENSO teleconnections plays an important role in variations of δ18Op at the interannual scale and that the more depleted oxygen stable isotopic composition of vapor (δ18Oυ) from the northwestern region of India during a La Niña year intensifies the lower δ18Op at Lhasa in a La Niña year. The study’s results have implications for the interpretation of past variations of archives with precipitation stable isotopes, such as ice cores, tree rings, lake sediments, and speleothems, in this region.

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Holocene Lake Evolution and Glacial Fluctuations Indicated by Carbonate Minerals and Their Isotopic Compositions in the Sediments of a Glacial Melt Recharge Lake on the Northwestern Tibetan Plateau

Frontiers in Earth Science ◽

10.3389/feart.2021.656281 ◽

2021 ◽

Vol 9 ◽

Author(s):

Minghui Li ◽

Liping Zhu ◽

Junbo Wang ◽

Jianting Ju ◽

Chong Liu ◽

...

Keyword(s):

Tibetan Plateau ◽

Lake Water ◽

The Tibetan Plateau ◽

Carbonate Minerals ◽

Cold Event ◽

Glacial Meltwater ◽

The Holocene ◽

Closed Basin ◽

Lake Evolution ◽

Cold Events

Lakes and glaciers are widely distributed on the Tibetan Plateau and are linked via hydrological processes. They are experiencing rapid changes due to global warming, but their relationships during the Holocene are less well known due to limited coupled geological records. Here, we analyzed the δ13C-VPDB and δ18O-VPDB values and ion content of calcite and aragonite in a 407-cm-long sediment core from Guozha Co, a closed basin on the northwestern Tibetan Plateau supplied by glacial meltwater, in order to understand how the lake responded to glacier changes during the Holocene. Our results indicate that the glacial meltwater lowered the lake’s temperature and the δ18Olake water and δ18Oendogenic + authigenic carbonate values and diluted the ion concentrations in the lake water. Three stages of evolution, 8.7–4.0, 4.0–1.5, and 1.5 kyr BP to present, are distinguished based on the decrease in glacial meltwater recharge. Guozha Co has been a closed basin since at least 8.7 kyr BP, and it has changed from a fresh water lake during 8.7–1.5 kyr BP to a brackish lake from 1.5 kyr BP to present due to several climate events. The famous 4.2 kyr BP cold event was identified in the core at 4.0 kyr BP, while warm events occurred at 6.2, 3.9, 2.2, 0.9, and 0.4 kyr BP. Both glaciers and lakes in this area are controlled by climate, but they exhibit opposite changes, that is, glaciers retreat and lakes expand, and vice versa. Our results provide an accurate interpretation of the cold events based on carbonate minerals and carbon–oxygen isotopes in glacial meltwater–recharged lake sediments.

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