Spatial, seasonal, and source variability in the stable oxygen and hydrogen isotopic composition of tap waters throughout the USA

2013 ◽  
Vol 28 (21) ◽  
pp. 5382-5422 ◽  
Author(s):  
Jurate M. Landwehr ◽  
Tyler B. Coplen ◽  
David W. Stewart
Keyword(s):  
Isotopic Composition ◽  
The Usa ◽  
Stable Oxygen ◽  
Hydrogen Isotopic Composition

scholarly journals Seasonal changes in the D  /  H ratio of fatty acids of pelagic microorganisms in the coastal North Sea

2016 ◽  
Vol 13 (19) ◽  
pp. 5527-5539 ◽  
Author(s):  
Sandra Mariam Heinzelmann ◽  
Nicole Jane Bale ◽  
Laura Villanueva ◽  
Danielle Sinke-Schoen ◽  
Catharina Johanna Maria Philippart ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Isotopic Composition ◽  
North Sea ◽  
Phytoplankton Bloom ◽  
Isotopic Fractionation ◽  
Spring Phytoplankton Bloom ◽  
Fractionation Factor ◽  
Culture Studies ◽  
Hydrogen Isotopic Composition

Abstract. Culture studies of microorganisms have shown that the hydrogen isotopic composition of fatty acids depends on their metabolism, but there are only few environmental studies available to confirm this observation. Here we studied the seasonal variability of the deuterium-to-hydrogen (D / H) ratio of fatty acids in the coastal Dutch North Sea and compared this with the diversity of the phyto- and bacterioplankton. Over the year, the stable hydrogen isotopic fractionation factor ε between fatty acids and water (εlipid/water) ranged between −172 and −237 ‰, the algal-derived polyunsaturated fatty acid nC20:5 generally being the most D-depleted (−177 to −235 ‰) and nC18:0 the least D-depleted fatty acid (−172 to −210 ‰). The in general highly D-depleted nC20:5 is in agreement with culture studies, which indicates that photoautotrophic microorganisms produce fatty acids which are significantly depleted in D relative to water. The εlipid/water of all fatty acids showed a transient shift towards increased fractionation during the spring phytoplankton bloom, indicated by increasing chlorophyll a concentrations and relative abundance of the nC20:5 polyunsaturated fatty acids, suggesting increased contributions of photoautotrophy. Time periods with decreased fractionation (less negative εlipid/water values) can potentially be explained by an increased contribution of heterotrophy to the fatty acid pool. Our results show that the hydrogen isotopic composition of fatty acids is a promising tool to assess the community metabolism of coastal plankton potentially in combination with the isotopic analysis of more specific biomarker lipids.

Hydrogen isotopic composition of the water in CR chondrites

2013 ◽  
Vol 106 ◽  
pp. 111-133 ◽  
Author(s):  
L. Bonal ◽  
C.M.O’D. Alexander ◽  
G.R. Huss ◽  
K. Nagashima ◽  
E. Quirico ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Hydrogen Isotopic Composition

scholarly journals Variations of stable oxygen and hydrogen isotopes in the pingo ice core, south of the Gydan Peninsula

2019 ◽  
Vol 488 (3) ◽  
pp. 323-328
Author(s):  
Yu. K. Vasil’chuk ◽  
A. N. Kurchatova ◽  
N. A. Budantseva ◽  
V. V. Rogov ◽  
J. N. Chizhova
Keyword(s):  
Isotopic Composition ◽  
Ice Core ◽  
Hydrogen Isotopes ◽  
Lake Area ◽  
Oxygen And Hydrogen Isotopes ◽  
Rapid Formation ◽  
Stable Oxygen ◽  
Dry Out ◽  
Small Scatter ◽  
Isotopic Profile

The vertical isotopic profile of the pingo Messoyakha-1 (coordinates: 68°30′32″ N, 79°59′53″ E) ice core, obtained in the south of the Gydan Peninsula in the Middle Messoyakha swell. There is no significant variations of the isotopic composition of pingo ice core: δ18О values vary from -14.98 to -16.60‰, δ2Н values vary from -117.9 to -12.8. This small scatter of values is probably the result of intense heaving and rather rapid formation of the pingo. Basing on the features of the pingo, it can be assumed that initially there was a lake of 0.5 km length and 0.3 km width in this site. Then, as a result of water draining to a nearby river, the lake began to dry out and alas, which occupies most of the primary lake area, was formed. Pingo arose during the freezing of the alas under its gradual drying.

On the relationship between stable isotopes and major impurity species as inferred from a two-dimensional firn sampling approach at EDML, East Antarctica

2021 ◽  
Author(s):  
Thomas Münch ◽  
Maria Hörhold ◽  
Johannes Freitag ◽  
Melanie Behrens ◽  
Thomas Laepple
Keyword(s):  
Isotopic Composition ◽  
Interannual Variability ◽  
Ice Core ◽  
Ice Cores ◽  
Temperature Changes ◽  
Impurity Species ◽  
Intermittent Precipitation ◽  
Ice Core Record ◽  
Stable Oxygen ◽  
Atmospheric Variations

<p>Ice cores constitute a major palaeoclimate archive by recording, among many others, the atmospheric variations of stable oxygen and hydrogen isotopic composition of water and of soluble ionic impurities. While impurities are used as proxies for, e.g., variations in sea ice, marine biological activity and volcanism, stable isotope records are the main source of information for the reconstruction of polar temperature changes.</p><p>However, such reconstruction efforts are complicated by the fact that temperature is by far not the only driver of isotopic composition changes. A single isotopic ice-core record will comprise variations caused by a multitude of processes, from variable atmospheric circulation and moisture pathways to the intermittency of precipitation and finally to the mixing and re-location of surface snow by wind drift (stratigraphic noise). Under the assumption that specific trace components are originally deposited with the precipitated snow and its isotopic composition, the retrieved impurity records should display a similar spatial and seasonal to interannual variability as the isotope records, caused by local stratigraphic noise as well as the time-variable and intermittent precipitation patterns, respectively.</p><p>In this contribution, we investigate the possible relationship between isotope and impurity data at the East Antarctic low-accumulation site EDML. We sampled and analysed isotopic composition and major impurity species on a four metre deep and 50 metre long trench. This enables us (1) to study the spatial (horizontal times vertical) relationship in the data, and (2) to analyse and compare the seasonal and interannual variability after removing the strong contribution of local stratigraphic noise. By this, the study improves our understanding of the depositional mechanisms that play an important role for the formation of ice-core records, and it offers to investigate the potential of using impurities to correct isotopic variability in order to improve temperature reconstructions.</p>

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