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Articles de revues sur le sujet « Isotopic model »

Auteur : Grafiati

Publié le 10 mars 2023

Mis à jour le 31 juillet 2025

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1

Sedaghatpour, Fatemeh, and Stein B. Jacobsen. "Magnesium stable isotopes support the lunar magma ocean cumulate remelting model for mare basalts." Proceedings of the National Academy of Sciences 116, no. 1 (2018): 73–78. http://dx.doi.org/10.1073/pnas.1811377115.

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We report high-precision Mg isotopic analyses of different types of lunar samples including two pristine Mg-suite rocks (72415 and 76535), basalts, anorthosites, breccias, mineral separates, and lunar meteorites. The Mg isotopic composition of the dunite 72415 (δ25Mg = −0.140 ± 0.010‰, δ26Mg = −0.291 ± 0.018‰), the most Mg-rich and possibly the oldest lunar sample, may provide the best estimate of the Mg isotopic composition of the bulk silicate Moon (BSM). This δ26Mg value of the Moon is similar to those of the Earth and chondrites and reflects both the relative homogeneity of Mg isotopes in

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Sturm, C., Q. Zhang, and D. Noone. "An introduction to stable water isotopes in climate models: benefits of forward proxy modelling for paleoclimatology." Climate of the Past Discussions 5, no. 3 (2009): 1697–729. http://dx.doi.org/10.5194/cpd-5-1697-2009.

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Abstract. Stable water isotopes have been measured in a wide range of climate archives, with the purpose of reconstructing regional climate variations. Yet the common assumption that the isotopic signal is a direct indicator of temperature proves to be misleading under certain circumstances, since its relationship with temperature also depends on e.g. atmospheric circulation and precipitation seasonality. The present article introduces the principles, benefits and caveats of using climate models with embedded water isotopes as a support for the interpretation of isotopic climate archives. A sh

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Cauquoin, Alexandre, Martin Werner, and Gerrit Lohmann. "Water isotopes – climate relationships for the mid-Holocene and preindustrial period simulated with an isotope-enabled version of MPI-ESM." Climate of the Past 15, no. 6 (2019): 1913–37. http://dx.doi.org/10.5194/cp-15-1913-2019.

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Abstract. We present here the first results, for the preindustrial and mid-Holocene climatological periods, of the newly developed isotope-enhanced version of the fully coupled Earth system model MPI-ESM, called hereafter MPI-ESM-wiso. The water stable isotopes H216O, H218O and HDO have been implemented into all components of the coupled model setup. The mid-Holocene provides the opportunity to evaluate the model response to changes in the seasonal and latitudinal distribution of insolation induced by different orbital forcing conditions. The results of our equilibrium simulations allow us to

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Lu, Yanwei, Mingyi Wen, Peiyue Li, Jiaping Liang, Haoyan Wei, and Min Li. "An Improved Craig–Gordon Isotopic Model: Accounting for Transpiration Effects on the Isotopic Composition of Residual Water during Evapotranspiration." Agronomy 13, no. 6 (2023): 1531. http://dx.doi.org/10.3390/agronomy13061531.

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Evapotranspiration (ET) is a crucial process in the terrestrial water cycle, and understanding its stable isotopic evolution is essential for comprehending hydrological processes. The Craig–Gordon (C-G) model is widely used to describe isotopic fractionation during pure evaporation. However, in natural environments, ET involves both transpiration (T) and evaporation (E), and the traditional C-G model does not account for the effect of transpiration on isotopic fractionation. To address this gap, we propose the evapotranspiration-unified C-G (ET-UCG) model, which extends the C-G model by incorp

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Halder, J., S. Terzer, L. I. Wassenaar, L. J. Araguás-Araguás, and P. K. Aggarwal. "The Global Network of Isotopes in Rivers (GNIR): integration of water isotopes in watershed observation and riverine research." Hydrology and Earth System Sciences 19, no. 8 (2015): 3419–31. http://dx.doi.org/10.5194/hess-19-3419-2015.

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Abstract. We introduce a new online global database of riverine water stable isotopes (Global Network of Isotopes in Rivers, GNIR) and evaluate its longer-term data holdings. Overall, 218 GNIR river stations were clustered into three different groups based on the seasonal variation in their isotopic composition, which was closely coupled to precipitation and snowmelt water runoff regimes. Sinusoidal fit functions revealed phases within each grouping and deviations from the sinusoidal functions revealed important river alterations or hydrological processes in these watersheds. The seasonal isot

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Halder, J., S. Terzer, L. I. Wassenaar, L. J. Araguás-Araguás, and P. K. Aggarwal. "The Global Network of Isotopes in Rivers (GNIR): integration of water isotopes in watershed observation and riverine research." Hydrology and Earth System Sciences Discussions 12, no. 4 (2015): 4047–79. http://dx.doi.org/10.5194/hessd-12-4047-2015.

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Abstract. We introduce a new online global database of riverine water stable isotopes (Global Network of Isotopes in Rivers) and evaluate its longer-term data holdings. Overall, 218 GNIR river stations were clustered into 3 different groups based on the seasonal variation in their isotopic composition, which was closely coupled to precipitation and snow-melt water run-off regimes. Sinusoidal fit functions revealed periodic phases within each grouping and deviations from the sinusoidal functions revealed important river alterations or hydrological processes in these watersheds. The seasonal iso

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Salamalikis, Vasileios, та Athanassios A. Argiriou. "Validation and Bias Correction of Monthly δ18O Precipitation Time Series from ECHAM5-Wiso Model in Central Europe". Oxygen 2, № 2 (2022): 109–24. http://dx.doi.org/10.3390/oxygen2020010.

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Simulated stable oxygen isotopic composition (δ18O) of precipitation from isotope-enabled GCMs (iGCMs) have gained significant visibility nowadays. This study evaluates bias correction techniques to reduce the systematic and dispersion biases of the modelled δ18O by the ECHAM5-wiso model compared to the Global Network of Isotopes in Precipitation (GNIP) observations over Central Europe. mean bias error (MBE) and Root Mean Square Error (RMSE) are substantially reduced by more than 70% and 10%, respectively, depending on the bias correction scheme, with better results for Generalized Additive Mo

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Michalski, G., S. K. Bhattacharya, and G. Girsch. "NO<sub>x</sub> cycle and the tropospheric ozone isotope anomaly: an experimental investigation." Atmospheric Chemistry and Physics 14, no. 10 (2014): 4935–53. http://dx.doi.org/10.5194/acp-14-4935-2014.

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Abstract. The oxygen isotope composition of nitrogen oxides (NOx) in the atmosphere is a useful tool for understanding the oxidation of NOx into nitric acid / nitrate in the atmosphere. A set of experiments was conducted to examine change in isotopic composition of NOx due to NOx–O2–O3 photochemical cycling. At low NOx / O2 mixing ratios, NOx became progressively and nearly equally enriched in 17O and 18O over time until it reached a steady state with Δ17O values of 39.3 ± 1.9‰ and δ18O values of 84.2 ± 4‰, relative to the isotopic composition of the initial O2 gas. As the mixing ratios were i

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Orlowski, Natalie, Philipp Kraft, Jakob Pferdmenges, and Lutz Breuer. "Exploring water cycle dynamics by sampling multiple stable water isotope pools in a developed landscape in Germany." Hydrology and Earth System Sciences 20, no. 9 (2016): 3873–94. http://dx.doi.org/10.5194/hess-20-3873-2016.

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Abstract. A dual stable water isotope (δ2H and δ18O) study was conducted in the developed (managed) landscape of the Schwingbach catchment (Germany). The 2-year weekly to biweekly measurements of precipitation, stream, and groundwater isotopes revealed that surface and groundwater are isotopically disconnected from the annual precipitation cycle but showed bidirectional interactions between each other. Apparently, snowmelt played a fundamental role for groundwater recharge explaining the observed differences to precipitation δ values. A spatially distributed snapshot sampling of soil water iso

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Erez, Jonathan, Anne Bouevitch, and Aaron Kaplan. "Carbon isotope fractionation by photosynthetic aquatic microorganisms: experiments with Synechococcus PCC7942, and a simple carbon flux model." Canadian Journal of Botany 76, no. 6 (1998): 1109–18. http://dx.doi.org/10.1139/b98-067.

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Stable carbon isotopes (12C and 13C) are widely used to trace biogeochemical processes in the global carbon cycle. Natural fractionation of carbon isotopes is mainly due to the discrimination of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) against 13C during photosynthesis. In marine and other aquatic microorganisms, this fractionation is lowered when the dissolved CO2 (CO2(aq)) is decreasing, but the underlying mechanisms are poorly understood. Cultured Synechococcus PCC7942 showed maximum isotopic fractionations of -33omicron (in delta 13C units) relative to the total inorganic

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Ballutaud, Marine, Morgane Travers-Trolet, Paul Marchal, et al. "Inferences to estimate consumer’s diet using stable isotopes: Insights from a dynamic mixing model." PLOS ONE 17, no. 2 (2022): e0263454. http://dx.doi.org/10.1371/journal.pone.0263454.

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Stable isotope ratios are used to reconstruct animal diet in trophic ecology via mixing models. Several assumptions of stable isotope mixing models are critical, i.e., constant trophic discrimination factor and isotopic equilibrium between the consumer and its diet. The isotopic turnover rate (λ and its counterpart the half-life) affects the dynamics of isotopic incorporation for an organism and the isotopic equilibrium assumption: λ involves a time lag between the real assimilated diet and the diet estimated by mixing models at the individual scale. Current stable isotope mixing model studies

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Malpica-Cruz, Luis, Sharon Z. Herzka, Oscar Sosa-Nishizaki, and Juan Pablo Lazo. "Tissue-specific isotope trophic discrimination factors and turnover rates in a marine elasmobranch: empirical and modeling results." Canadian Journal of Fisheries and Aquatic Sciences 69, no. 3 (2012): 551–64. http://dx.doi.org/10.1139/f2011-172.

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There are very few studies reporting isotopic trophic discrimination factors and turnover rates for marine elasmobranchs. A controlled laboratory experiment was conducted to estimate carbon and nitrogen isotope trophic discrimination factors and isotope turnover rates for blood, liver, muscle, cartilage tissue, and fin samples of neonate to young-of-the-year leopard sharks ( Triakis semifasciata ). Trophic discrimination factors varied (0.13‰–1.98‰ for δ13C and 1.08‰–1.76‰ for δ15N). Tissues reached or were close to isotopic equilibrium to the new diet after about a threefold biomass gain and

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Dütsch, Marina, Stephan Pfahl, Miro Meyer, and Heini Wernli. "Lagrangian process attribution of isotopic variations in near-surface water vapour in a 30-year regional climate simulation over Europe." Atmospheric Chemistry and Physics 18, no. 3 (2018): 1653–69. http://dx.doi.org/10.5194/acp-18-1653-2018.

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Abstract. Stable water isotopes are naturally available tracers of moisture in the atmosphere. Due to isotopic fractionation, they record information about condensation and evaporation processes during the transport of air parcels, and therefore present a valuable means for studying the global water cycle. However, the meteorological processes driving isotopic variations are complex and not very well understood so far, in particular on short (hourly to daily) timescales. This study presents a Lagrangian method for attributing the isotopic composition of air parcels to meteorological processes,

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Gallart, Francesc, Sebastián González-Fuentes, and Pilar Llorens. "Technical note: Isotopic fractionation of evaporating waters: effect of sub-daily atmospheric variations and eventual depletion of heavy isotopes." Hydrology and Earth System Sciences 28, no. 1 (2024): 229–39. http://dx.doi.org/10.5194/hess-28-229-2024.

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Abstract. Isotopic fractionation of evaporating waters has been studied constantly in recent decades, particularly because it enables calculation of both the volume of water evaporated from a water body and the isotopic composition of its source water. We studied the stable water isotopic composition of an artificial pan filled with water and subject to total evaporation in a sub-humid environment, in order to put into practice an operational method for estimating the time since disconnection of riverine pools when these are sampled for the quality of aquatic life. Results indicate that (i) wh

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Li, Jie, Tao Tao, Zhonghe Pang, et al. "Identification of Different Moisture Sources through Isotopic Monitoring during a Storm Event." Journal of Hydrometeorology 16, no. 4 (2015): 1918–27. http://dx.doi.org/10.1175/jhm-d-15-0005.1.

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Abstract Rain samples were collected for isotopic analyses during the entirety of an extreme rainfall event in Beijing, China, on 21 July 2012, the city’s heaviest rainfall event in the past six decades. Four stages of the storm event have been identified with corresponding isotopic characteristics: 1) isotopes deplete as rain increases, 2) isotopes enrich as rain decreases, 3) isotopes quickly deplete as rain increases, and 4) isotopes remain constant as rain reduces to a small amount. The rainout effect dominates the depletion of isotopic composition in stages 1 and 3. The incursion of a new

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Extier, Thomas, Thibaut Caley, and Didier M. Roche. "Modelling water isotopologues (¹H²H¹⁶O, ¹H₂¹⁷O) in the coupled numerical climate model iLOVECLIM (version 1.1.5)." Geoscientific Model Development 17, no. 5 (2024): 2117–39. http://dx.doi.org/10.5194/gmd-17-2117-2024.

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Abstract. Stable water isotopes are used to infer changes in the hydrological cycle for different climate periods and various climatic archives. Following previous developments of δ18O in the coupled climate model of intermediate complexity, iLOVECLIM, we present here the implementation of the 1H2H16O and 1H217O water isotopes in the different components of this model and calculate the associated secondary markers deuterium excess (d-excess) and oxygen-17 excess (17O-excess) in the atmosphere and ocean. So far, the latter has only been modelled by the atmospheric model LMDZ4. Results of a 5000

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Gao, Jing, V. Masson-Delmotte, T. Yao, L. Tian, C. Risi, and G. Hoffmann. "Precipitation Water Stable Isotopes in the South Tibetan Plateau: Observations and Modeling*." Journal of Climate 24, no. 13 (2011): 3161–78. http://dx.doi.org/10.1175/2010jcli3736.1.

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Abstract Measurements of precipitation isotopic composition have been conducted on a daily basis for 1 yr at Bomi, in the southeast Tibetan Plateau, an area affected by the interaction of the southwest monsoon, the westerlies, and Tibetan high pressure systems, as well as at Lhasa, situated west of Bomi. The measured isotope signals are analyzed both on an event basis and on a seasonal scale using available meteorological information and airmass trajectories. The processes driving daily and seasonal isotopic variability are investigated using multidecadal climate simulations forced by twentiet

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Qu, Simin, Xueqiu Chen, Yifan Wang, et al. "Isotopic Characteristics of Precipitation and Origin of Moisture Sources in Hemuqiao Catchment, a Small Watershed in the Lower Reach of Yangtze River." Water 10, no. 9 (2018): 1170. http://dx.doi.org/10.3390/w10091170.

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The stable isotopes of oxygen and hydrogen in the water cycle have become a significant tool to study run-off formation, hydrograph separation, and the origin of precipitation. Precipitation assessment based on isotopic data has a potential implication for moisture sources. In the study, δD and δ18O of precipitation samples collected from six rainfall events were analyzed for stable isotope composition to provide implication of isotopic characteristics as well as moisture sources in Hemuqiao basin within Lake Tai drainage basin, eastern China. In these events, stable oxygen and hydrogen isotop

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Neumann, Thomas A., and Edwin D. Waddington. "Effects of firn ventilation on isotopic exchange." Journal of Glaciology 50, no. 169 (2004): 183–94. http://dx.doi.org/10.3189/172756504781830150.

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AbstractA new model of isotopic diffusion in the upper few meters of firn tracks the isotopic composition of both the ice matrix and the pore-space vapor through time in two dimensions. Stable isotopes in the vapor phase move through the firn by diffusion along concentration gradients and by advection. Wind-driven ventilation carries atmospheric water vapor into the firn, where it mixes with existing pore-space vapor. Unlike previous models, our model allows disequilibrium between pore-space vapor and the surrounding snow grains. We also calculate the isotopic effects of ventilation-driven sub

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Chen, Mengli, Edward A. Boyle, Jong-Mi Lee, et al. "Lead isotope exchange between dissolved and fluvial particulate matter: a laboratory study from the Johor River estuary." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 374, no. 2081 (2016): 20160054. http://dx.doi.org/10.1098/rsta.2016.0054.

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Atmospheric aerosols are the dominant source of Pb to the modern marine environment, and as a result, in most regions of the ocean the Pb isotopic composition of dissolved Pb in the surface ocean (and in corals) matches that of the regional aerosols. In the Singapore Strait, however, there is a large offset between seawater dissolved and coral Pb isotopes and that of the regional aerosols. We propose that this difference results from isotope exchange between dissolved Pb supplied by anthropogenic aerosol deposition and adsorbed natural crustal Pb on weathered particles delivered to the ocean b

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Roche, D. M. "δ<sup>18</sup>O water isotope in the <i>i</i>LOVECLIM model (version 1.0) – Part 1: Implementation and verification". Geoscientific Model Development 6, № 5 (2013): 1481–91. http://dx.doi.org/10.5194/gmd-6-1481-2013.

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Abstract. A new 18O stable water isotope scheme is developed for three components of the iLOVECLIM coupled climate model: atmospheric, oceanic and land surface. The equations required to reproduce the fractionation of stable water isotopes in the simplified atmospheric model ECBilt are developed consistently with the moisture scheme. Simplifications in the processes are made to account for the simplified vertical structure including only one moist layer. Implementation of these equations together with a passive tracer scheme for the ocean and a equilibrium fractionation scheme for the land sur

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Esteban, G. A., A. Perujo, and F. Legarda. "Study of the Isotope Effects in the Hydrogen Transport in Polycrystalline Tungsten." Materials Science Forum 480-481 (March 2005): 537–42. http://dx.doi.org/10.4028/www.scientific.net/msf.480-481.537.

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A time-dependent gas-phase isovolumetric desorption technique has been used to evaluate the diffusive transport parameters of hydrogen isotopes in polycrystalline tungsten in the temperatures range 673 to 1073 K and driving pressures from 1.3 104 to 105 Pa. Experiments have been run with both protium and deuterium obtaining their respective transport parameters diffusivity (D), Sieverts’ constant (Ks), the trap site density (Nt) and the trapping activation energy (Et). Isotope effects on these transport parameters are analysed and modelled. Because the classical isotope relation for diffusivit

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Comas-Bru, Laia, and Sandy P. Harrison. "SISAL: Bringing Added Value to Speleothem Research." Quaternary 2, no. 1 (2019): 7. http://dx.doi.org/10.3390/quat2010007.

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Isotopic records from speleothems are an important source of information about past climates and, given the increase in the number of isotope-enabled climate models, are likely to become an important tool for climate model evaluation. SISAL (Speleothem Isotopes Synthesis and Analysis) have created a global database of isotopic records from speleothems in order to facilitate regional analyses and data-model comparison. The papers in this Special Issue showcase the use of the database for regional analyses. In this paper, we discuss some of the important issues underpinning the use of speleothem

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Völpel, Rike, André Paul, Annegret Krandick, Stefan Mulitza, and Michael Schulz. "Stable water isotopes in the MITgcm." Geoscientific Model Development 10, no. 8 (2017): 3125–44. http://dx.doi.org/10.5194/gmd-10-3125-2017.

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Abstract. We present the first results of the implementation of stable water isotopes in the Massachusetts Institute of Technology general circulation model (MITgcm). The model is forced with the isotopic content of precipitation and water vapor from an atmospheric general circulation model (NCAR IsoCAM), while the fractionation during evaporation is treated explicitly in the MITgcm. Results of the equilibrium simulation under pre-industrial conditions are compared to observational data and measurements of plankton tow records (the oxygen isotopic composition of planktic foraminiferal calcite)

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Fujii, T., F. Moynier, A. Agranier, E. Ponzevera, and M. Abe. "Nuclear field shift effect of lead in ligand exchange reaction using a crown ether." Proceedings in Radiochemistry 1, no. 1 (2011): 387–92. http://dx.doi.org/10.1524/rcpr.2011.0069.

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AbstractLead isotopes were fractionated by the liquid-liquid extraction technique between an aqueous phase and a crown ether. After purification by ion-exchange chemistry, the 207Pb/206Pb and 208Pb/206Pb isotopic ratios were measured by multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Isotope fractionations > 0.05‰ have been found. The conventional equilibrium mass-dependent isotope effect estimated by an ab initio calculation was smaller than the Pb isotope fractionation experimentally obtained. Conventional mass-dependent isotope fractionation is not a valuable

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Kim, Songyi, Yeongcheol Han, Soon Do Hur, Kei Yoshimura, and Jeonghoon Lee. "Relating Moisture Transport to Stable Water Vapor Isotopic Variations of Ambient Wintertime along the Western Coast of Korea." Atmosphere 10, no. 12 (2019): 806. http://dx.doi.org/10.3390/atmos10120806.

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Atmospheric water vapor transfers energy, causes meteorological phenomena and can be modified by climate change in the western coast region of Korea. In Korea, previous studies have utilized precipitation isotopic compositions in the water cycle for correlations with climate variables, but there are few studies using water vapor isotopes. In this study, water vapor was directly collected by a cryogenic method, analyzed for its isotopic compositions, and used to trace the origin and history of water vapor in the western coastal region of Korea during the winter of 2015/2016. Our analysis of pai

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Pieterse, G., M. C. Krol, A. M. Batenburg, et al. "Global modelling of H<sub>2</sub> mixing ratios and isotopic compositions with the TM5 model." Atmospheric Chemistry and Physics Discussions 11, no. 2 (2011): 5811–66. http://dx.doi.org/10.5194/acpd-11-5811-2011.

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Abstract. The isotopic composition of molecular hydrogen (H2) contains independent information for constraining the global H2 budget. To explore this, we have implemented hydrogen sources and sinks, including their isotopic composition, into the global chemistry transport model TM5. For the first time, a global model now includes a simplified but explicit isotope reaction scheme for the photochemical production of H2. We present a comparison of modelled results for the H2 mixing ratio and isotope composition with available measurements on the seasonal to inter annual time scales for the years

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Jahn, A., K. Lindsay, X. Giraud, et al. "Carbon isotopes in the ocean model of the Community Earth System Model (CESM1)." Geoscientific Model Development 8, no. 8 (2015): 2419–34. http://dx.doi.org/10.5194/gmd-8-2419-2015.

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Abstract. Carbon isotopes in the ocean are frequently used as paleoclimate proxies and as present-day geochemical ocean tracers. In order to allow a more direct comparison of climate model results with this large and currently underutilized data set, we added a carbon isotope module to the ocean model of the Community Earth System Model (CESM), containing the cycling of the stable isotope 13C and the radioactive isotope 14C. We implemented the 14C tracer in two ways: in the "abiotic" case, the 14C tracer is only subject to air–sea gas exchange, physical transport, and radioactive decay, while

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Jahn, A., K. Lindsay, X. Giraud, et al. "Carbon isotopes in the ocean model of the Community Earth System Model (CESM1)." Geoscientific Model Development Discussions 7, no. 6 (2014): 7461–503. http://dx.doi.org/10.5194/gmdd-7-7461-2014.

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Abstract. Carbon isotopes in the ocean are frequently used as paleo climate proxies and as present-day geochemical ocean tracers. In order to allow a more direct comparison of climate model results with this large and currently underutilized dataset, we added a carbon isotope module to the ocean model of the Community Earth System Model (CESM), containing the cycling of the stable isotope 13C and the radioactive isotope 14C. We implemented the 14C tracer in two ways: in the "abiotic" case, the 14C tracer is only subject to air–sea gas exchange, physical transport, and radioactive decay, while

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Arnoldi, Jean-François, Jenny Rose Bortoluzzi, Hugh Rowland, et al. "How strongly does diet variation explain variation in isotope values of animal consumers?" PLOS ONE 19, no. 6 (2024): e0301900. http://dx.doi.org/10.1371/journal.pone.0301900.

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Analysis of stable isotopes in consumers is used commonly to study their ecological and/or environmental niche. There is, however, considerable debate regarding how isotopic values relate to diet and how other sources of variation confound this link, which can undermine the utility. From the analysis of a simple, but general, model of isotopic incorporation in consumer organisms, we examine the relationship between isotopic variance among individuals, and diet variability within a consumer population. We show that variance in consumer isotope values is directly proportional to variation in die

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Piovano, Thea I., Doerthe Tetzlaff, Sean K. Carey, Nadine J. Shatilla, Aaron Smith, and Chris Soulsby. "Spatially distributed tracer-aided runoff modelling and dynamics of storage and water ages in a permafrost-influenced catchment." Hydrology and Earth System Sciences 23, no. 6 (2019): 2507–23. http://dx.doi.org/10.5194/hess-23-2507-2019.

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Abstract. Permafrost strongly controls hydrological processes in cold regions. Our understanding of how changes in seasonal and perennial frozen ground disposition and linked storage dynamics affect runoff generation processes remains limited. Storage dynamics and water redistribution are influenced by the seasonal variability and spatial heterogeneity of frozen ground, snow accumulation and melt. Stable isotopes are potentially useful for quantifying the dynamics of water sources, flow paths and ages, yet few studies have employed isotope data in permafrost-influenced catchments. Here, we app

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Uriarte, Amaya, Alberto García, Aurelio Ortega, Fernando De la Gándara, José Quintanilla, and Raúl Laiz-Carrión. "Isotopic discrimination factors and nitrogen turnover rates in reared Atlantic bluefin tuna larvae (Thunnus thynnus): effects of maternal transmission." Scientia Marina 80, no. 4 (2016): 447. http://dx.doi.org/10.3989/scimar.04435.25a.

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The use of stable isotope analysis to study animal diets requires estimates of isotopic turnover rates (half time, t50) and discrimination factors (Δ) for an accurate interpretation of trophic patterns. The stable isotopes of carbon and nitrogen were analysed for eggs and reared larvae of Thunnus thynnus, as well as for the different diets supplied during the experiment. The results showed high values of δ15N in eggs and larvae (n=646) until 4 DAH. After this time lapse, the stable isotope values declined progressively until 12 DAH, when notochord flexion began. The δ13C showed an inverse tren

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Pieterse, G., M. C. Krol, A. M. Batenburg, et al. "Global modelling of H<sub>2</sub> mixing ratios and isotopic compositions with the TM5 model." Atmospheric Chemistry and Physics 11, no. 14 (2011): 7001–26. http://dx.doi.org/10.5194/acp-11-7001-2011.

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Abstract. The isotopic composition of molecular hydrogen (H2) contains independent information for constraining the global H2 budget. To explore this, we have implemented hydrogen sources and sinks, including their stable isotopic composition and isotope fractionation constants, into the global chemistry transport model TM5. For the first time, a global model now includes a simplified but explicit isotope reaction scheme for the photochemical production of H2. We present a comparison of modelled results for the H2 mixing ratio and isotope composition with available measurements on seasonal to

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Pfahl, S., H. Wernli, and K. Yoshimura. "The isotopic composition of precipitation from a winter storm – a case study with the limited-area model COSMO<sub>iso</sub>." Atmospheric Chemistry and Physics Discussions 11, no. 9 (2011): 26521–70. http://dx.doi.org/10.5194/acpd-11-26521-2011.

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Abstract. Stable water isotopes are valuable tracers of the atmospheric water cycle, and potentially provide useful information also on weather-related processes. In order to further explore this potential, the water isotopes H218O and HDO are incorporated into the limited-area model COSMO. In a first case study, the new COSMOiso model is used for simulating a winter storm event in January 1986 over the eastern United States associated with intense frontal precipitation. The modelled isotope ratios in precipitation and water vapour are compared to spatially distributed δ18O observations. COSMO

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Pfahl, S., H. Wernli, and K. Yoshimura. "The isotopic composition of precipitation from a winter storm – a case study with the limited-area model COSMO<sub>iso</sub>." Atmospheric Chemistry and Physics 12, no. 3 (2012): 1629–48. http://dx.doi.org/10.5194/acp-12-1629-2012.

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Abstract. Stable water isotopes are valuable tracers of the atmospheric water cycle, and potentially provide useful information also on weather-related processes. In order to further explore this potential, the water isotopes H218O and HDO are incorporated into the limited-area model COSMO. In a first case study, the new COSMOiso model is used for simulating a winter storm event in January 1986 over the eastern United States associated with intense frontal precipitation. The modelled isotope ratios in precipitation and water vapour are compared to spatially distributed δ18O observations. COSMO

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Müller, Tom, Mauro Fischer, Stuart N. Lane, and Bettina Schaefli. "Separating snow and ice melt using water stable isotopes and glacio-hydrological modelling: towards improving the application of isotope analyses in highly glacierized catchments." Cryosphere 19, no. 1 (2025): 423–58. https://doi.org/10.5194/tc-19-423-2025.

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Abstract. Glacio-hydrological models are widely used for estimating current and future streamflow across spatial scales, utilizing various data sources, notably observed streamflow and snow and/or ice accumulation, as well as ablation observations. However, modelling highly glacierized catchments poses challenges due to data scarcity and complex spatio-temporal meteorological conditions, leading to input data uncertainty and potential misestimation of the contribution of snow and ice melt to streamflow. Some studies propose using water stable isotopes to estimate shares of rain, snow and ice i

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Li, Jianghanyang, Xuan Zhang, John Orlando, Geoffrey Tyndall та Greg Michalski. "Quantifying the nitrogen isotope effects during photochemical equilibrium between NO and NO<sub>2</sub>: implications for <i>δ</i><sup>15</sup>N in tropospheric reactive nitrogen". Atmospheric Chemistry and Physics 20, № 16 (2020): 9805–19. http://dx.doi.org/10.5194/acp-20-9805-2020.

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Abstract. Nitrogen isotope fractionations between nitrogen oxides (NO and NO2) play a significant role in determining the nitrogen isotopic compositions (δ15N) of atmospheric reactive nitrogen. Both the equilibrium isotopic exchange between NO and NO2 molecules and the isotope effects occurring during the NOx photochemical cycle are important, but both are not well constrained. The nighttime and daytime isotopic fractionations between NO and NO2 in an atmospheric simulation chamber at atmospherically relevant NOx levels were measured. Then, the impact of NOx level and NO2 photolysis rate on th

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Comas-Bru, Laia, Sandy P. Harrison, Martin Werner, Kira Rehfeld, Nick Scroxton, and Cristina Veiga-Pires. "Evaluating model outputs using integrated global speleothem records of climate change since the last glacial." Climate of the Past 15, no. 4 (2019): 1557–79. http://dx.doi.org/10.5194/cp-15-1557-2019.

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Abstract. Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data–model comparisons. Here, we illustrate this using 456 globally distributed speleothem δ18O records from an updated version of th

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Lewicka-Szczebak, Dominika, Maciej Piotr Lewicki, and Reinhard Well. "N<sub>2</sub>O isotope approaches for source partitioning of N<sub>2</sub>O production and estimation of N<sub>2</sub>O reduction – validation with the <sup>15</sup>N gas-flux method in laboratory and field studies." Biogeosciences 17, no. 22 (2020): 5513–37. http://dx.doi.org/10.5194/bg-17-5513-2020.

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Abstract. The approaches based on natural abundance N2O stable isotopes are often applied for the estimation of mixing proportions between various N2O-producing pathways as well as for estimation of the extent of N2O reduction to N2. But such applications are associated with numerous uncertainties; hence, their limited accuracy needs to be considered. Here we present the first systematic validation of these methods for laboratory and field studies by applying the 15N gas-flux method as the reference approach. Besides applying dual-isotope plots for interpretation of N2O isotopic data, for the

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Hermoso de Mendoza, Ignacio, Etienne Boucher, Fabio Gennaretti, Aliénor Lavergne, Robert Field, and Laia Andreu-Hayles. "A new snow module improves predictions of the isotope-enabled MAIDENiso forest growth model." Geoscientific Model Development 15, no. 5 (2022): 1931–52. http://dx.doi.org/10.5194/gmd-15-1931-2022.

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Abstract. The representation of snow processes in forest growth models is necessary to accurately predict the hydrological cycle in boreal ecosystems and the isotopic signature of soil water extracted by trees, photosynthates and tree-ring cellulose. Yet, most process-based models do not include a snow module; consequently, their simulations may be biased in cold environments. Here, we modified the MAIDENiso model to incorporate a new snow module that simulates snow accumulation, melting and sublimation, as well as thermal exchanges driving freezing and thawing of the snow and the soil. We tes

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Zhao, Heng, Yanjie Li, Wenhui Liu, Guchun Zhang, and Yanjun Wang. "The Dynamic Evolution Model of the Chemical and Carbon Isotopic Composition of C1–3 during the Hydrocarbon Generation Process." Molecules 29, no. 2 (2024): 476. http://dx.doi.org/10.3390/molecules29020476.

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A new approach is presented in this paper for the dynamic modeling of the chemical and isotopic evolution of C1–3 during the hydrocarbon generation process. Based on systematic data obtained from published papers for the pyrolysis of various hydrocarbon sources (type I kerogen/source rock, type II kerogen/source rock, type III kerogen/source rock, crude oil, and asphalt, etc.), the empirical evolution framework of the chemical and isotopic composition of C1–3 during the hydrocarbon generation process was built. Although the empirical framework was built only by fitting a large amount of pyroly

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Harris, Eliza, Philipp Fischer, Maciej P. Lewicki, Dominika Lewicka-Szczebak, Stephen J. Harris, and Fernando Perez-Cruz. "Technical note: A Bayesian mixing model to unravel isotopic data and quantify trace gas production and consumption pathways for time series data – Time-resolved FRactionation And Mixing Evaluation (TimeFRAME)." Biogeosciences 21, no. 16 (2024): 3641–63. http://dx.doi.org/10.5194/bg-21-3641-2024.

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Abstract. Isotopic measurements of trace gases such as N2O, CO2, and CH4 contain valuable information about production and consumption pathways. Quantification of the underlying pathways contributing to variability in isotopic time series can provide answers to key scientific questions, such as the contribution of nitrification and denitrification to N2O emissions under different environmental conditions or the drivers of multiyear variability in atmospheric CH4 growth rate. However, there is currently no data analysis package available to solve isotopic production, mixing, and consumption pro

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Seeger, Stefan, and Markus Weiler. "Temporal dynamics of tree xylem water isotopes: in situ monitoring and modeling." Biogeosciences 18, no. 15 (2021): 4603–27. http://dx.doi.org/10.5194/bg-18-4603-2021.

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Abstract. We developed a setup for a fully automated, high-frequency in situ monitoring system of the stable water isotope deuterium and 18O in soil water and tree xylem. The setup was tested for 12 weeks within an isotopic labeling experiment during a large artificial sprinkling experiment including three mature European beech (Fagus sylvatica) trees. Our setup allowed for one measurement every 12–20 min, enabling us to obtain about seven measurements per day for each of our 15 in situ probes in the soil and tree xylem. While the labeling induced an abrupt step pulse in the soil water isotopi

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C. Banda, Limbikani, Michael Rivett, Robert Kalin, et al. "Seasonally Variant Stable Isotope Baseline Characterisation of Malawi’s Shire River Basin to Support Integrated Water Resources Management." Water 12, no. 5 (2020): 1410. http://dx.doi.org/10.3390/w12051410.

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Integrated Water Resources Management (IWRM) is vital to the future of Malawi and motivates this study’s provision of the first stable isotope baseline characterization of the Shire River Basin (SRB). The SRB drains much of Southern Malawi and receives the sole outflow of Lake Malawi whose catchment extends over much of Central and Northern Malawi (and Tanzania and Mozambique). Stable isotope (283) and hydrochemical (150) samples were collected in 2017–2018 and analysed at Malawi’s recently commissioned National Isotopes Laboratory. Distinct surface water dry-season isotope enrichment and wet-

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Marrocchi, Yves, Maxime Piralla, and François L. H. Tissot. "Iron Isotope Constraints on the Structure of the Early Solar System." Astrophysical Journal Letters 954, no. 1 (2023): L27. http://dx.doi.org/10.3847/2041-8213/acefd1.

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Abstract The recent advent of nontraditional isotopic systems has revealed that meteorites display a fundamental isotopic dichotomy between noncarbonaceous (NC) and carbonaceous (C) groups, which represent material from the inner and outer solar system, respectively. On the basis of iron isotope anomalies, this view has recently been challenged in favor of a circumsolar disk structured into three distinct reservoirs (the so-called isotopic trichotomy). In this scenario, the CI chondrites—a rare type of carbonaceous chondrites with chemical composition similar to that of the Sun’s photosphere—w

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Binns, W. R., M. E. Wiedenbeck, T. T. von Rosenvinge, et al. "The Isotopic Abundances of Galactic Cosmic Rays with Atomic Number 29 ≤ Z ≤ 38." Astrophysical Journal 936, no. 1 (2022): 13. http://dx.doi.org/10.3847/1538-4357/ac82e7.

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Abstract The Cosmic Ray Isotope Spectrometer (CRIS) on the Advanced Composition Explorer spacecraft has been operating successfully in a halo orbit about the L1 Lagrange point since late 1997. We report here the isotopic composition of the Galactic cosmic ray (GCR) elements with 29 ≤ Z ≤ 38 derived from more than 20 years of CRIS data. Using a model of cosmic-ray transport in the Galaxy and the solar system (SS), we have derived from these observations the isotopic composition of the accelerated material at the GCR source (GCRS). Comparison of the isotopic fractions of these elements in the GC

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Michalski, G., S. K. Bhattacharya, and G. Girsch. "NO<sub>x</sub> cycle and tropospheric ozone isotope anomaly: an experimental investigation." Atmospheric Chemistry and Physics Discussions 13, no. 4 (2013): 9443–83. http://dx.doi.org/10.5194/acpd-13-9443-2013.

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Abstract. The oxygen isotope composition of nitrogen oxides (NOx) in the atmosphere may be a useful tool for understanding the oxidation of NOx into nitric acid/nitrate in the atmosphere. A set of experiments were conducted to examine changes in isotopic composition of NOx due to O3-NOx photochemical cycling. At low NO2/O2 mixing ratios, NO2 becomes progressively and nearly equally enriched in 17O and 18O over time until it reaches a steady state with Δ17O values of 40.6 ± 1.9‰ and δ18O values of 84.2 ± 4‰, relative to the isotopic composition of the O2 gas. As the mixing ratio increases, isot

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Jensen, Alexandria, William Ford, James Fox, and Admin Husic. "Improving In-Stream Nutrient Routines in Water Quality Models Using Stable Isotope Tracers: A Review and Synthesis." Transactions of the ASABE 61, no. 1 (2018): 139–57. http://dx.doi.org/10.13031/trans.12545.

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Abstract. Water quality models serve as an economically feasible alternative to quantify fluxes of nutrient pollution and to simulate effective mitigation strategies; however, their applicability is often questioned due to broad uncertainties in model structure and parameterization, leading to uncertain outputs. We argue that reduction of uncertainty is partially achieved by integrating stable isotope data streams within the water quality model architecture. This article outlines the use of stable isotopes as a response variable within water quality models to improve the model boundary conditi

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Wang, Pei, Yujing Deng, and Zhongwang Wei. "Modeling Investigation of Diurnal Variations in Water Flux and Its Components with Stable Isotopic Tracers." Atmosphere 10, no. 7 (2019): 403. http://dx.doi.org/10.3390/atmos10070403.

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The isotopic compositions of water fluxes provide valuable insights into the hydrological cycle and are widely used to quantify biosphere–atmosphere exchange processes. However, the combination of water isotope approaches with water flux components remains challenging. The Iso-SPAC (coupled heat, water with isotopic tracer in soil–plant–atmosphere-continuum) model is a useful framework for simulating the dynamics of water flux and its components, and for coupling with isotopic fractionation and mixing processes. Here, we traced the isotopic fractionation processes with separate soil evaporatio

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Werner, M., B. Haese, X. Xu, X. Zhang, M. Butzin, and G. Lohmann. "Glacial–interglacial changes in H<sub>2</sub><sup>18</sup>O, HDO and deuterium excess – results from the fully coupled ECHAM5/MPI-OM Earth system model." Geoscientific Model Development 9, no. 2 (2016): 647–70. http://dx.doi.org/10.5194/gmd-9-647-2016.

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Abstract. In this study we present the first results of a new isotope-enabled general circulation model set-up. The model consists of the fully coupled ECHAM5/MPI-OM atmosphere–ocean model, enhanced by the JSBACH interactive land surface scheme and an explicit hydrological discharge scheme to close the global water budget. Stable water isotopes H218O and HDO have been incorporated into all relevant model components. Results of two equilibrium simulations under pre-industrial and Last Glacial Maximum conditions are analysed and compared to observational data and paleoclimate records for evaluat

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