• A record of the hydrogen isotopic composition of terrestrial leaf waxes (δD wax ) in sediment cores from Lake Titicaca provides new insight into the precipitation history of the Central Andes and controls of South American Summer Monsoon (SASM) variability since the last glacial period. (umn.edu)
  • The stable isotopic composition of precipitation was analyzed in samples collected between March 2012 and March 2013. (northumbria.ac.uk)
  • With one exception (Artà), the isotopic composition of waters in caves located along the coast (Drac, Vallgornera, Cala Varques, Tancada, and Son Sant Martí) indicates Mediterranean-sourced moisture masses. (northumbria.ac.uk)
  • Overall, our survey highlights the diversity of isotopic composition and evolution in Pituffik surface waters, and our complete isotopic and geospatial database provides a strong foundation for future researchers to study hydrological changes at Pituffik and across the Arctic. (essopenarchive.org)
  • This study presents a spatio-temporal analysis of the isotopic composition (δ18O, δ2 H, d-excess) during the 2018 rainy season in the Sonora River Basin (SRB), a region influenced by the characteristic weather conditions of the North American Monsoon (NAM). (una.ac.cr)
  • The rainfall isotopic composition is comparable with the Global Meteoric Water Line (GMWL) and with the records of the Global Isotope Network in Precipitation (GNIP) in Chihuahua, Mexico, between 1962 and 1988, and Tucson, Arizona (2018). (una.ac.cr)
  • The objective of this study is to reveal the isotopic composition of ice and meltwater in glaciated regions of South-Eastern Altai. (mdpi.com)
  • The paper depicts differences between the isotopic composition of glacier ice from several types of glaciers and from various locations. (mdpi.com)
  • Spatial variability in the isotopic composition of water in small catchments and its effect on hydrograph separation. (uzh.ch)
  • In 2009, the Commission on Isotopic Abundances and Atomic Weights (CIAAW) of the International Union of Pure and Applied Chemistry (IUPAC) introduced the interval notation to express the standard atomic weights of elements whose isotopic composition varies significantly in nature. (degruyter.com)
  • In the absence of detailed knowledge about the isotopic composition of a material, or when such details may safely be ignored, the probability distribution assigned to the standard atomic weight intervals may be taken as rectangular (or, uniform). (degruyter.com)
  • When information about the provenance of the material, or other information about the isotopic composition needs to be taken into account, then this distribution may be non-uniform. (degruyter.com)
  • Concerning the provision that the isotopic composition of a "normal" material should not have been modified significantly in a geologically brief period, John Böhlke (2015, personal communication) has pointed out that "high and low atomic weight values of light elements commonly are due to isotopic fractionation processes that are happening every day," as arise in respiration, evaporation, and dissolution. (degruyter.com)
  • The 2009 recommendation to use interval notation did achieve the valuable educational goal of drawing attention to the fact that isotopic composition can vary among natural materials, hence so do the atomic weights [ 8 ]. (degruyter.com)
  • The oxygen and hydrogen isotopic composition δ 2 H and δ 18 O of leaf and lake water reflects the isotopic composition of source water/precipitation modified by evapo(transpi)rative enrichment. (copernicus.org)
  • In this contribution, we review the modern inputs of DSi to the ocean and the controls on their isotopic composition, and assess the evidence for their variability on millennial-plus timescales.Today, 9.55 × 10 12 mol yr -1 DSi enters the ocean, of which roughly 64% and 25% are direct riverine inputs of DSi, and DSi from dissolution of aeolian and riverborne sediment, respectively. (lu.se)
  • We observe a trend of increasing monsoonal precipitation from the early to the late Holocene, consistent with summer insolation forcing of the SASM, but similar hydrologic variability on precessional timescales is not apparent during the last glacial period. (umn.edu)
  • Overall, this study demonstrates the relative importance of high-latitude versus tropical forcing as a dominant control on glacial SASM precipitation variability. (umn.edu)
  • Isotopic gradients correlate with precipitation amount, temperature, with distance to source areas of evaporation and often follow topographic features. (copernicus.org)
  • Water isotopes are valuable tracers of hydrological processes, but logistical challenges limit the length and scope of isotopic monitoring in High Arctic landscapes. (essopenarchive.org)
  • We find that the spatial and temporal variability of lake isotopes is dominated by evaporation and connectivity to summer meltwater sources, while evaporation determines interannual isotopic changes. (essopenarchive.org)
  • Stable water isotopes in HadCM3: Isotopic signature of El Niño-Southern Oscillation and the tropical amount effect. (copernicus.org)
  • These distributions, however, are not intended to reflect the natural variability of the abundances of the different isotopes in the earth's crust or in any other environment. (degruyter.com)
  • Furthermore, the use of isotopic niches underlines the utility of stable isotopes in studying the potential impacts of environmental change on feeding ecology. (frontiersin.org)
  • The use of C. finmarchicus δ 15 N and δ 13 C values as a baseline explained a portion of the spatial variability in isotopes, attributing some of the variation to physical and biological sources. (int-res.com)
  • Accordingly, the results illustrate the importance of spatial variability when interpreting trophic structure from stable isotopes. (int-res.com)
  • Understanding the isotopic variability and the sources of moisture in modern climate systems is required to develop speleothem isotope-based climate reconstructions. (northumbria.ac.uk)
  • Water isotope samples taken at individual times or sites in similar periglacial landscapes likely have limited regional representativeness, and increasing the spatiotemporal extent of isotopic sampling is critical to producing accurate and informative High Arctic paleoclimate reconstructions. (essopenarchive.org)
  • The temporal variability of rainfall isotope ratios was Δ18O = 7.4‰ and Δ2 H = 49.8‰, with a clear depletion pattern (low δ18O) as the monsoon rainy season progressed. (una.ac.cr)
  • Interdecadal-decadal climate variability from multicoral oxygen isotope records in the South Pacific Convergence Zone region since 1650 A.D. (columbia.edu)
  • Isotope-enabled general circulation models (iGCMs) have been established to explicitly simulate the processes that lead to these distributions, in response to the changes in radiative forcing, boundary conditions, and including effects of internal variability of the climate system. (copernicus.org)
  • We obtain encouraging results for the prediction of isotope variability in Greenland and the Antarctic. (copernicus.org)
  • Hansen JH, Hedeholm RB, Sünksen K, Tang Christensen J, Grønkjær P (2012) Spatial variability of carbon (δ 13 C) and nitrogen (δ 15 N) stable isotope ratios in an Arctic marine food web. (int-res.com)
  • Exploring the sensitivity of (13)Delta to possible respiratory isotope effects, we conclude that isotopic disequilibria between the gross fluxes of photosynthesis and day respiration can explain the high observed (13)Delta values during net photosynthetic gas exchange. (who.int)
  • We discuss implications of source variation for designing sampling protocols, interpreting isotopic signatures, and establishing trophic links between plants and consumers. (scielo.br)
  • Hence, significant differences in isotopic signatures on both large and small spatial scales were less related to food web structure than to different physical and biological properties of the water masses. (int-res.com)
  • Here, using a longitudinal dataset on the long-lived black-browed albatross (Thalassarche melanophris) as a model organism, we test the hypothesis that environmental variability directly affects divorce. (researchgate.net)
  • Isotopic variation within food sources adds uncertainty to models intended to reconstruct trophic pathways. (scielo.br)
  • Assessing isotopic niches may help to better understand the specific trophic responses to change in the environment. (frontiersin.org)
  • The proportion of BC-like polycyclic aromatic structures decreases downstream, but marked spatial variability in abundance and Δ 14 C values of DBC molecular markers imply dynamic sources and cycling in a manner that is incongruent with bulk DOC. (nature.com)
  • We find a high spatial variability of prediction accuracy, modest in many locations with the presently employed approaches. (copernicus.org)
  • Further research on tooth dentine and enamel will explore the age at which the isotopic differences first appeared and investigate different patterns of mobility and landscape-use in the study area. (eurekalert.org)
  • Normalization according to lipid content further reduces variability since differences in individuals serum lipid concentrations are cancelled out. (cdc.gov)
  • Groundwater systems act as a buffer against climate variability when surface water systems are low. (iaea.org)
  • Here, we present a comprehensive isotopic survey of 535 water samples taken in 2018-2019 of the lakes, streams, and other surface waters of the periglacial Pituffik Peninsula in far northwest Greenland. (essopenarchive.org)
  • Este estudio presenta un análisis espacio-temporal de la composición isotópica (δ18O, δ2 H, d-exceso) durante la temporada de lluvias 2018 en la Cuenca del Río Sonora (SRB), una región influenciada por las condiciones climáticas características del Monzón de América del Norte ( NAM). (una.ac.cr)
  • La composición isotópica de las precipitaciones es comparable con la Línea de Agua Meteórica Global (GMWL) y con los registros de la Red Global de Isótopos en Precipitación (GNIP) en Chihuahua, México, entre 1962 y 1988, y Tucson, Arizona (2018). (una.ac.cr)
  • Green A, Chadwick MA, Jones PJS (2018) Variability of UK seagrass sediment carbon: Implications for blue carbon estimates and marine conservation management. (plos.org)
  • Although limited, the isotopic data presented here constitute the baseline for future studies using speleothem δ18O records for western Mediterranean paleoclimate reconstructions. (northumbria.ac.uk)
  • Strong relationships between atmospheric circulation and isotopologue variability exist, mitigated by fractionation during phase transitions of water. (copernicus.org)
  • Seasonal variability and individual consistency in gray seal (Halichoerus grypus) isotopic niches. (lsu.edu)
  • At its 2009 meeting in Vienna, the IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW) resolved to express the standard atomic weight of ten elements - including hydrogen, carbon, and oxygen - by means of intervals that characterize the span of their atomic-weight values in so-called "normal" materials. (degruyter.com)
  • To assess the isotopic variation across the island, water samples from eight caves were collected. (northumbria.ac.uk)
  • Variation in the functioning of the continental Si cycle on timescales similar to the residence time of DSi in the ocean (~10 ka) may therefore contribute to downcore variability in δ 30 Si BSi on millennial or longer timescales. (lu.se)
  • We sampled 13 Zostera marina meadows along the southwest coast of the UK to assess the variability in their sedimentary organic carbon (OC) stocks. (plos.org)
  • The predicted contribution of different carbon sources to the consumer biomass changed between models as a function of source variability. (scielo.br)
  • We have been examining these problems by modeling the effects of loading the atmosphere with H2, characterizing the stable isotopic (D/H) variability of atmospheric H2, and determining the isotopic characteristics of H2 of different origins. (caltech.edu)
  • Stream isotopic compositions vary in both space and time based on the relative source balance of tundra snowpack meltwater versus surface melt from the nearby Greenland Ice Sheet. (essopenarchive.org)
  • For twelve elements, a range of atomic weights is given to reflect the isotopic variability in natural materials. (euronuclear.org)
  • The assignment of suitable probability distributions to the atomic weight intervals is consistent with the CIAAW's goal of emphasizing the variability of the atomic weight values in nature. (degruyter.com)
  • Because of the variability of customs processes and procedures in different countries, ASTM International cannot guarantee transit times to international destinations. (astm.org)
  • An isotopic analysis of megalithic graves and caves in Spain may suggest the existence of a degree of differentiation in the lifeways of people buried in these different funerary sites, according to a study published September 27, 2017 in the open-access journal PLOS ONE by Teresa Fernández-Crespo and Rick Schulting from the University of the Basque Country, Spain, and the University of Oxford, UK. (eurekalert.org)
  • The researchers' isotopic analysis of both megalithic graves and caves suggests a similar C3 plant-based human diet, mostly consisting of wheat and barley, as well as a substantial amount of protein from cattle and sheep. (eurekalert.org)
  • Flint pebbles show little variability, consistent with a single source. (uwo.ca)
  • Such a condition of initial thorough isotopic mixing of the original magma body followed by rapid chemical segregation is suited to the assumptions of whole-rock and mineral isochron dating. (answersingenesis.org)
  • Long-distance migration will also be investigated using feather isotopic signature. (uibk.ac.at)
  • Alice will determine the production rates, variability, and structure of H 2 O and CO, and CO 2 gas surrounding the nucleus and the far-UV properties of solid grains in the coma. (esa.int)
  • Compared to previous studies, it will take into account the fine-scale structure of urban settlements to better catch the variability in urban habitat quality. (uibk.ac.at)
  • This technique is based on the assumption that "you are what you eat (plus a few ‰)" (DeNiro and Epstein 1976 ), as a consumer's tissues reflect the isotopic array of the ingested foods. (springer.com)
  • The δ 18 O, δ 2 H, and deuterium-excess values of these samples, representing 196 unique sites, grant us unprecedented insight into the environmental drivers of the region's hydrology and water isotopic variability. (essopenarchive.org)
  • They document glacial values that are typically 0.5 to 1.0‰ lower than interglacial values and together hint at coherent and predictable glacial-interglacial variability in whole-ocean δ 30 Si driven by a change in mean δ 30 Si of the inputs. (lu.se)
  • The isotopic lapse rate was found to be − 1.0‰ in δ18O per km of elevation as a result of the topography relief and rainout effects within the basin. (una.ac.cr)