Verification of the Relationship between the Isotopic Composition of Ice Wedges and Cold-season Temperature over the Recent 80 Years in the Northern Permafrost Zone of Russia

2020 ◽  
Vol 45 (11) ◽  
pp. 791-796
Author(s):  
Yu. K. Vasil’chuk ◽  
G. V. Surkova
Keyword(s):  
Isotopic Composition ◽  
Cold Season ◽  
Permafrost Zone ◽  
The Relationship

New equation to decipher the relationship between carbon isotopic composition of methane and maturity of gas source rocks

2021 ◽  
Vol 64 (3) ◽  
pp. 470-493 ◽  
Author(s):  
Jianping Chen ◽  
Xulong Wang ◽  
Jianfa Chen ◽  
Yunyan Ni ◽  
Baoli Xiang ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotopic Composition ◽  
Source Rocks ◽  
Carbon Isotopic ◽  
Gas Source ◽  
New Equation ◽  
The Relationship

scholarly journals Investigation of post-depositional processing of nitrate in East Antarctic snow: isotopic constraints on photolytic loss, re-oxidation, and source inputs

2015 ◽  
Vol 15 (16) ◽  
pp. 9435-9453 ◽  
Author(s):  
G. Shi ◽  
A. M. Buffen ◽  
M. G. Hastings ◽  
C. Li ◽  
H. Ma ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Mass Fraction ◽  
Stratospheric Ozone ◽  
Warm Season ◽  
Cold Season ◽  
Depth Interval ◽  
Depositional Processes ◽  
Antarctic Snow ◽  
Exponential Change ◽  
The Impact

Abstract. Snowpits along a traverse from coastal East Antarctica to the summit of the ice sheet (Dome Argus) are used to investigate the post-depositional processing of nitrate (NO3−) in snow. Seven snowpits from sites with accumulation rates between 24 and 172 kg m−2 a−1 were sampled to depths of 150 to 300 cm. At sites from the continental interior (low accumulation, < 55 kg m−2 a−1), nitrate mass fraction is generally > 200 ng g−1 in surface snow and decreases quickly with depth to < 50 ng g−1. Considerably increasing values of δ15N of nitrate are also observed (16–461 ‰ vs. air N2), particularly in the top 20 cm, which is consistent with predicted fractionation constants for the photolysis of nitrate. The δ18O of nitrate (17–84 ‰ vs. VSMOW (Vienna Standard Mean Ocean Water)), on the other hand, decreases with increasing δ15N, suggestive of secondary formation of nitrate in situ (following photolysis) with a low δ18O source. Previous studies have suggested that δ15N and δ18O of nitrate at deeper snow depths should be predictable based upon an exponential change derived near the surface. At deeper depths sampled in this study, however, the relationship between nitrate mass fraction and δ18O changes, with increasing δ18O of nitrate observed between 100 and 200 cm. Predicting the impact of post-depositional loss, and therefore changes in the isotopes with depth, is highly sensitive to the depth interval over which an exponential change is assumed. In the snowpits collected closer to the coast (accumulation > 91 kg m−2 a−1), there are no obvious trends detected with depth and instead seasonality in nitrate mass fraction and isotopic composition is found. In comparison to the interior sites, the coastal pits are lower in δ15N (−15–71 ‰ vs. air N2) and higher in δ18O of nitrate (53–111 ‰ vs. VSMOW). The relationships found amongst mass fraction, δ15N, δ18O and Δ17O (Δ17O = δ17O–0.52 × δ18O) of nitrate cannot be explained by local post-depositional processes alone, and are instead interpreted in the context of a primary atmospheric signal. Consistent with other Antarctic observational and modeling studies, the isotopic results are suggestive of an important influence of stratospheric ozone chemistry on nitrate formation during the cold season and a mix of tropospheric sources and chemistry during the warm season. Overall, the findings in this study speak to the sensitivity of nitrate isotopic composition to post-depositional processing and highlight the strength of combined use of the nitrogen and oxygen isotopes for a mechanistic understanding of this processing.

scholarly journals Isotopic composition of blood plasma carbon in patients with endocrine diseases

1993 ◽  
Vol 39 (1) ◽  
pp. 36-40
Author(s):  
A. A. Ivlev ◽  
N. P. Goncharov
Keyword(s):  
Isotopic Composition ◽  
Blood Plasma ◽  
Carbon Isotopic Composition ◽  
Mean Value ◽  
Cellular Division ◽  
Disease Heterogeneity ◽  
Clear Cut ◽  
Carbon Isotopic ◽  
Adults And Children ◽  
The Relationship

Forty-eight patients suffering from diabetes mellitus, obesity, hyper- and hypothyrosis, Icenko-Cushings disease were examined to elucidate the relationship between blood plasma carbon isotopic composition and the type of the endocrine disease. This value varied within the range of 19.7 to 24.7 , the mean value being 5 . Blood plasma carbon in the diabetics is enriched for 12C light isotope (delta-13C from 23.0 to 24.5 ) as against a similar characteristic in obese patients (delta-13C from 20.5 to 21.99 ). Patients with hypo- and hyperthyrosis and the Icenko- Cushings disease have a wider range of delta-13C values that seems to be explained by the Icenko-Cushings disease heterogeneity and the presence of biorhythms. Clear-cut isotopic differences in the blood sera of adults and children were revealed whatever the disease type, these differences indicating the changes in cellular metabolism energy in the ontogenesis. These data can be satisfactorily explained within the frames of the model of cellular division of carbon isotopes, suggested previously.

scholarly journals Interannual variability of isotopic composition in water vapor over western Africa and its relationship to ENSO

2015 ◽  
Vol 15 (6) ◽  
pp. 3193-3204 ◽  
Author(s):  
A. Okazaki ◽  
Y. Satoh ◽  
G. Tremoy ◽  
F. Vimeux ◽  
R. Scheepmaker ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Southern Oscillation ◽  
Monsoon Season ◽  
Precipitation Amount ◽  
Isotopic Signature ◽  
Atmospheric Environment ◽  
Global Spectral Model ◽  
Near Surface ◽  
Western Africa ◽  
The Relationship

Abstract. This study was performed to examine the relationship between isotopic composition in near-surface vapor (δ18Ov) over western Africa during the monsoon season and El Niño–Southern Oscillation (ENSO) activity using the Isotope-incorporated Global Spectral Model. The model was evaluated using a satellite and in situ observations at daily to interannual timescales. The model provided an accurate simulation of the spatial pattern and seasonal and interannual variations of isotopic composition in column and surface vapor and precipitation over western Africa. Encouraged by this result, we conducted a simulation stretching 34 years (1979–2012) to investigate the relationship between atmospheric environment and isotopic signature on an interannual timescale. The simulation indicated that the depletion in the monsoon season does not appear every year at Niamey. The major difference between the composite fields with and without depletion was in the amount of precipitation in the upstream area of Niamey. As the interannual variation of the precipitation amount is influenced by the ENSO, we regressed the monsoon season averaged δ18Ov from the model and annually averaged NINO3 index and found a statistically significant correlation (R = 0.56, P < 0.01) at Niamey. This relationship suggests that there is a possibility of reconstructing past western African monsoon activity and ENSO using climate proxies.

Developing Micro-Raman Mass Spectrometry for Measuring Carbon Isotopic Composition of Carbon Dioxide

2007 ◽  
Vol 61 (7) ◽  
pp. 701-705 ◽  
Author(s):  
Masashi Arakawa ◽  
Junji Yamamoto ◽  
Hiroyuki Kagi
Keyword(s):  
Isotopic Composition ◽  
Intensity Ratio ◽  
High Spatial Resolution ◽  
Carbon Isotopic Composition ◽  
Peak Intensity Ratio ◽  
Factors Affecting ◽  
Isotopic Compositions ◽  
Carbon Isotopic ◽  
Peak Intensity ◽  
The Relationship

We investigated the applicability of micro-Raman spectroscopy for determining carbon isotopic compositions (13C/12C) of minute CO2 fluid inclusions in minerals. This method is nondestructive and has sufficiently high spatial resolution (1 μm) to measure each fluid inclusion independently. Raman spectra of CO2 fluid have 12CO2-origin peaks at about 1285 cm−1 and 1389 cm−1 (v12− and v12+) and a 13CO2-origin peak at about 1370 cm−1 (v13+). The relationship between carbon isotopic compositions and peak intensity ratios of v12+ and v13+ was calibrated. Considering several factors affecting the peak intensity ratio, the error in obtained carbon isotopic composition was 2% (20‰). The reproducibility of the intensity ratio under the same experimental environment was 0.5% (5‰). Within these error values, we can distinguish biogenic CO2 from abiogenic CO2.

scholarly journals Accounting for local meteorological effects in the ozone time-series of Lovozero (Kola Peninsula)

2003 ◽  
Vol 3 (4) ◽  
pp. 941-949 ◽  
Author(s):  
O. A. Tarasova ◽  
A. Yu. Karpetchko
Keyword(s):  
Regression Model ◽  
Kola Peninsula ◽  
Meteorological Parameters ◽  
Surface Ozone ◽  
Meteorological Condition ◽  
Cold Season ◽  
Meteorological Conditions ◽  
Short Term ◽  
The Relationship ◽  
Meteorological Effects

Abstract. The relationship between local meteorological conditions and the surface ozone variability was studied by means of statistical modeling, using ozone and meteorological parameters measured at Lovozero (250 m a.s.l., 68.5°N, 35.0°E, Kola Peninsula) for the period of 1999-2000. The regression model of daily mean ozone concentrations on such meteorological parameters as temperature, relative humidity and wind speed explains up to 70% of day-to-day ozone variability in terms of meteorological condition changes, if the seasonal cycle is also considered. A regression model was created for separated time scales of the variables. Short-term, synoptical and seasonal components are separated by means of Kolmogorov-Zurbenko filtering. The synoptical scale variations were chosen as the most informative from the point of their mutual relation with meteorological parameters. Almost 40% of surface ozone variations in time periods of 11-60 days can be explained by the regression model on separated scales that is 30% more efficient than ozone residuals usage. Quantitative and qualitative estimations of the relations between surface ozone and meteorological predictors let us preliminarily conclude that at the Lovozero site surface ozone variability is governed mainly by dynamical processes of various time scale rather than photochemistry, especially during the cold season.

scholarly journals Carbon stable isotope composition of charophyte organic matter in a small and shallow Spanish water body as a baseline for future trophic studies

2015 ◽  
Author(s):  
María Antonia Rodrigo ◽  
Adriana García ◽  
Allan R. Chivas
Keyword(s):  
Organic Matter ◽  
Isotopic Composition ◽  
Isotope Composition ◽  
Myriophyllum Spicatum ◽  
Reproductive Organs ◽  
Cold Season ◽  
Freshwater Ecosystems ◽  
Organic C ◽  
Isotopic Signatures ◽  
C And N

<p>Quantitative descriptions of foodweb structure based on isotope niche space require knowledge of producers’ isotopic signatures. In freshwater ecosystems charophytes are one of the main components of submerged vegetation and the feeding base for many herbivorous consumers, but knowledge about their organic carbon isotopic signatures is sparse. In this study, the δ<sup>13</sup>C organic values (and organic %C and %N) of the four species of submerged macrophytes (three charophytes - <em>Chara hispida</em>, <em>Nitella hyalina</em> and <em>Tolypella glomerata </em>- and one angiosperm, <em>Myriophyllum spicatum</em>) growing in a newly created shallow pond were measured monthly over a period of one year, to discern if i) all charophyte species susceptible to being food for consumers and growing in the same waterbody have the same C isotopic composition; ii) the δ<sup>13</sup>C values of a charophyte species change on a seasonal and spatial scale; iii) the different parts (apical nodes, internodes, rhizoids, reproductive organs, oospores) of a charophyte species have the same isotopic composition. The δ<sup>13</sup>C, %C and %N values of organic matter in the sediments where the plants were rooted were also measured as well as several limnological variables. The δ<sup>13</sup>C values for the angiosperm (-13.7±0.7‰) indicated <sup>13</sup>C-enrichment, whereas the <em>N. hyalina</em> δ<sup>13</sup>C values were the most negative (-22.4±0.7‰). The mean δ<sup>13</sup>C value for <em>C. hispida </em>was -19.0±1.0‰ and -20.7±0.8‰ for <em>T. glomerata.</em> <em>C. hispida</em> δ<sup>13</sup>C values had a significant seasonal variation with <sup>13</sup>C-poor values in the cold season, and slight spatial differences. Statistically significant differences were found between charophyte rhizoids (<sup>13</sup>C-enriched) and the other parts of the thalli. The δ<sup>13</sup>C values in the sediments varied throughout time (-13‰ to -26‰). The C content was lower in the charophytes than in the angiosperm and there were no large differences among the charophytes. Charophyte fructifications were enriched in organic C compared to the thalli parts. The study provides an isotopic baseline for further studies for the elucidation of higher trophic-level relationships which are particularly complex in shallow water bodies where interactions between the pelagic and the benthic zones are intricate.</p>

Control of Authenticity of Fruit Juices by Isotopic Analysis

1973 ◽  
Vol 56 (3) ◽  
pp. 739-742 ◽  
Author(s):  
Jacques Bricout
Keyword(s):  
Stable Isotopes ◽  
Isotopic Composition ◽  
Natural Water ◽  
Meteoric Water ◽  
Fruit Juice ◽  
Isotopic Analysis ◽  
Fruit Juices ◽  
Rain Water ◽  
Dilution Water ◽  
The Relationship

Abstract In order to differentiate a natural fruit juice from a dilute concentrate, we have investigated the isotopic composition of their water. We have chosen the stable isotopes deuterium and 18O. The water of orange juices is strongly enriched in heavy isotopes, as compared to rain water. This enrichment is much lower for French apple juices and seems to be due to evapotranspiration. The relationship between deuterium and 18O observed for meteoric water is modified in the fruits. If a fruit juice is concentrated and then rediluted with natural water, the isotopic composition of its water would be very similar to the original deuterium and 18O content of the dilution water. Isotopic analysis allows a very confident distinction between natural fruit juices and reconstituted juices.

High-resolution carbon and oxygen isotope record in modern brachiopod Pictothyris picta collected off Okinoshima, Japan

2021 ◽  
Author(s):  
Kazuma Oikawa ◽  
Hideko Takayanagi ◽  
Kazuyoshi Endo ◽  
Masa-aki Yoshida ◽  
Yasufumi Iryu
Keyword(s):  
Isotopic Composition ◽  
Isotope Fractionation ◽  
Growth Stage ◽  
Cold Season ◽  
Strong Positive Correlation ◽  
Isotopic Equilibrium ◽  
Ambient Seawater ◽  
Kinetic Isotope ◽  
Carbon And Oxygen Isotope ◽  
Fractionation Effect

&lt;p&gt;Carbon (&amp;#948;&lt;sup&gt;13&lt;/sup&gt;C) and oxygen (&amp;#948;&lt;sup&gt;18&lt;/sup&gt;O) isotope composition of Rhynchonelliformea brachiopods (hereafter, called &amp;#8216;brachiopods&amp;#8217;) have been regarded as useful paleoenvironmental indicators throughout the Phanerozoic. However, recent studies have revealed that the isotopic composition in modern brachiopod shells records not only environmental changes in ambient seawater but also is influenced by biological controls such as the chemical/isotopic composition of calcifying fluids and physiological processes (e.g., growth rates, metabolism). The latter is known as biological isotope fractionation effects, such as kinetic, metabolic, and pH effects. Recently, a new calcification mechanism in brachiopod shell formation, ion transport mechanism, was proposed. In this study, we measured &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O values of the primary (PL) and secondary (SL) shell layers of three &lt;em&gt;Pictothyris picta&lt;/em&gt; (one male and two female specimens) collected at a water depth of~61 m off Okinoshima to improve our understanding of biological isotope fractionation effects during their shell secretion. We obtained ontogenetic-series &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O profiles from the PL (PL-Ont) and the uppermost SL (SL-Ont) at the sampling resolution of 3 days to 8 months per sample. We obtained inner-series &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O profiles from the innermost SL (SL-In) as well. The variations in the &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O profiles of the PL-Ont showed similar trends to those of the SL-Ont. However, the PL-Ont values mostly exhibited relatively lower &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O values than those of the SL-Ont. Cross plots between the &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O values of the PL-Ont indicated a strong positive correlation and were lower than those of calcite precipitated in isotopic equilibrium with ambient seawater at the fast growth stage, suggesting the significant influence of the kinetic isotope fractionation effect. The SL was precipitated in oxygen isotopic equilibrium with ambient seawater regardless of the growth stage and/or the seasonal changes in living environments. Furthermore, the PL-Ont, SL-Ont, and SL-Inshowed similar &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O values during the cold season, indicating negligible influences of the kinetic, pH, and magnesium effects on &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O composition. The &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C values of the PL-Ont formed at the cold season (= micro-portion formed under the least kinetic isotope fractionation effect) were lower than those of the SL, indicating the stronger metabolic effect on the PL secretion. Our isotopic data showed that the time lag of the PL and the SL formation varies among specimens.&lt;/p&gt;

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