Stable isotopic composition reveals the spatial and temporal dynamics of discharge in the large river of Yarlungzangbo in the Tibetan Plateau

2018 ◽  
Vol 625 ◽  
pp. 373-381 ◽  
Author(s):  
Wei Ren ◽  
Tandong Yao ◽  
Shiyou Xie
Keyword(s):  
Tibetan Plateau ◽  
Isotopic Composition ◽  
Temporal Dynamics ◽  
Large River ◽  
The Tibetan Plateau ◽  
Stable Isotopic Composition ◽  
Spatial And Temporal Dynamics ◽  
Stable Isotopic

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

2018 ◽  
Vol 31 (3) ◽  
pp. 1173-1182 ◽  
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.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

Prediction method for determining the carbon stable isotopic composition of berry sugars in the original must of Chardonnay wines

2021 ◽  
pp. 130854
Author(s):  
Fumikazu Akamatsu ◽  
Hideaki Shimizu ◽  
Yukari Igi ◽  
Aya Kamada ◽  
Kazuya Koyama ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Prediction Method ◽  
Stable Isotopic Composition ◽  
Stable Isotopic

scholarly journals Stable isotopic composition of top consumers in Arctic cryoconite holes: revealing divergent roles in a supraglacial trophic network

2021 ◽  
Vol 18 (5) ◽  
pp. 1543-1557
Author(s):  
Tereza Novotná Jaroměřská ◽  
Jakub Trubač ◽  
Krzysztof Zawierucha ◽  
Lenka Vondrovicová ◽  
Miloslav Devetter ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Isotopic Ratio ◽  
Isotopic Fractionation ◽  
Mechanistic Explanation ◽  
High Arctic ◽  
Biologically Active ◽  
Glacier Surface ◽  
Stable Isotopic Composition ◽  
Stable Isotopic ◽  
Trophic Network

Abstract. Arctic cryoconite holes represent highly biologically active aquatic habitats on the glacier surface characterized by the dynamic nature of their formation and functioning. The most common cryoconite apex consumers are the cosmopolitan invertebrates – tardigrades and rotifers. Several studies have highlighted the potential relevance of tardigrades and rotifers to cryoconite holes' ecosystem functioning. However, due to the dominant occurrence of prokaryotes, these consumers are usually out of the major scope of most studies aimed at understanding biological processes on glaciers. The aim of this descriptive study is to present pioneering data on isotopic composition of tardigrades, rotifers and cryoconite from three High Arctic glaciers in Svalbard and discuss their role in a cryoconite hole trophic network. We found that tardigrades have lower δ15N values than rotifers, which indicates different food requirements or different isotopic fractionation of both consumers. The δ13C values revealed differences between consumers and organic matter in cryoconite among glaciers. However, the mechanistic explanation of these variations requires further investigation focused on the particular diet of cryoconite consumers and their isotopic ratio. Our study introduces the first observation of carbon and nitrogen stable isotopic composition of top consumers in cryoconite holes analysed by an improved method for cryoconite sample processing, paving the way for further studies of the supraglacial trophic network.

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