Affordable event and monthly rain samplers: Improving isotopic datasets to understand meteorological processes.

Rationale: Water-stable isotopes in rainfall are powerful tracers of atmospheric processes at different spatial and temporal scales. However, commercially available rain samplers for isotopic analysis are prohibitively expensive, especially for high spatial resolution networks and studies conducted in developing countries. A low-cost, simple, and robust sampler was designed for event and monthly rainfall samplings.

Investigating individual migration life histories: An isotopic case study from 17th to 18th century Nouvelle France.

Objectives: This isotopic study explores the mobility patterns of a growing urban population from Notre Dame's Catholic cemetery (1691-1796), located in Montreal (Canada). The site offers a unique opportunity to investigate early colonial settlement in Nouvelle France through individual life patterns.

Materials And Methods: Stable oxygen isotopic compositions (δO) were measured on the enamel of 32 individuals from the Notre Dame collection.

Characterization of vanillin carbon isotope delta reference materials.

Stable carbon isotope ratio measurements are used to investigate the provenance of vanillin. In this study, a variety of commercial vanillin samples and vanilla products were analyzed to provide a frame of reference for the variability of carbon isotope delta values in various vanillin samples, with the results ranging from -20.6 to -36.

Discontinuity in the Realization of the Vienna Peedee Belemnite Carbon Isotope Ratio Scale.

By convention, carbon isotope ratios are expressed relative to VPDB defined by the calcite standard NBS19 in the 1980s. [See T. Coplen, .

Characterisation of new reference materials IAEA-610, IAEA-611 and IAEA-612 aimed at the VPDB δ C scale realisation with small uncertainty.

Rationale: LSVEC, the second anchor Reference Material (RM) for the VPDB δ C scale realisation, was introduced in 2006. In 2015, its δ C value was found to be drifting and, in 2017, its use as an RM for δ C was officially discontinued by IUPAC. New RMs of low uncertainty are needed.

Designing working standards for stable H, C, and O isotope measurements in CO and H O.

Rationale: We address here the selection, preparation, calibration, storage, and use of carbonate and water working standards (WSs) for stable H, C, and O isotope measurements requiring the best possible precision and accuracy vs international reference materials (iRMs). This may be of interest for laboratories working intensively in the domains of the carbon and water cycles and of paleoclimate.

Methods: Defining a WS for stable C and O isotope studies requires combining mineralogical, physical, chemical (low Mg- and trace-carbonate), and isotopic measurements to select a carbonate fit for purpose; for water, two distinct deionized or distilled waters, with high and low δ H and δ O values, respectively, are normally used.

USGS44, a new high-purity calcium carbonate reference material for δ C measurements.

Rationale: The stable carbon isotopic (δ C) reference material (RM) LSVEC Li CO has been found to be unsuitable for δ C standardization work because its δ C value increases with exposure to atmospheric CO . A new CaCO RM, USGS44, has been prepared to alleviate this situation.

Methods: USGS44 was prepared from 8 kg of Merck high-purity CaCO .

Preparation and characterisation of IAEA-603, a new primary reference material aimed at the VPDB scale realisation for δ C and δ O determination.

Rationale: NBS19 carbonate, a primary reference material (RM) for the Vienna Pee Dee Belemnite (VPDB) scale realisation introduced in 1987, was exhausted in 2009, and no primary RM was available for several years. This study describes the preparation and characterisation of a new RM, IAEA-603 (Ca-carbonate, calcite of marble origin), which shall serve as a new primary RM (replacement for NBS19) or primary calibrator aimed at the highest realisation of the VPDB scale for δ C and δ O values, including the VPDB-CO δ O scale.

Methods: IAEA-603 preparation and characterisation (value transfer) against NBS19 were performed by addressing the major modern technical requirements for the production and characterisation of RMs (ISO Guide 35).

A New Technique to Determine the Phosphate Oxygen Isotope Composition of Freshwater Samples at Low Ambient Phosphate Concentration.

The oxygen isotope composition of dissolved inorganic phosphate (δO) offers new opportunities to understand the sources and the fate of phosphorus (P) in freshwater ecosystems. However, current analytical protocols for determining δO are unable to generate reliable data for samples in which ambient P concentrations are extremely low, precisely the systems in which δO may provide new and important insights into the biogeochemistry of P. In this Article, we report the development, testing and initial application of a new technique that enables δO analysis to be extended into such ecosystems.

Improved accuracy and precision of water stable isotope measurements using the direct vapour equilibration method.

Rationale: A method to measure the δ H and δ O composition of pore water in soil samples using direct vapour equilibration and laser spectrometry was first described in 2008, and was rapidly adopted. Here, we describe an improved setup to measure pore water δ H and δ O values through direct vapour equilibration with a laser spectrometer, combining a liquid and a vapour mode for water isotope analyses, and resulting in improved accuracy.

Methods: We first tested new gas sampling bags as part of the equilibration protocol.

Geochemical study of carbonate concretions from the aqueduct of Nîmes (southern France): a climatic record for the first centuries AD?

The first centuries AD in the Mediterranean region have generally been associated with a warm, stable climate. High-resolution sedimentary archives sensitive to local environmental change are needed to switch from this general frame to the regional scale. Similarly to cave speleothems, laminated carbonate deposits can grow in the channels of aqueducts which transported water from karstic springs during the Roman period.

North America's oldest boreal trees are more efficient water users due to increased [CO], but do not grow faster.

Due to anthropogenic emissions and changes in land use, trees are now exposed to atmospheric levels of [[Formula: see text]] that are unprecedented for 650,000 y [Lüthi et al. (2008) 453:379-382] (thousands of tree generations). Trees are expected to acclimate by modulating leaf-gas exchanges and alter water use efficiency which may result in forest productivity changes.

Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements: Caffeines, n-Alkanes, Fatty Acid Methyl Esters, Glycines, L-Valines, Polyethylenes, and Oils.

An international project developed, quality-tested, and determined isotope-δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-600 (caffeine). These new RMs enable users to normalize measurements of samples to isotope-δ scales. The RMs span a range of δ(2)H(VSMOW-SLAP) values from -210.

Processes governing the stable isotope composition of water in the St. Lawrence river system, Canada.

Linkages between δ(18)O-δ(2)H and hydrological processes have been investigated from isotopic time series recorded in the St. Lawrence River basin. Three stations were monitored from 1997 to 2008.

Field Metabolic Rate Is Dependent on Time-Activity Budget in Ring-Billed Gulls (Larus delawarensis) Breeding in an Anthropogenic Environment.

Environmental and behavioral factors have long been assumed to affect variation in avian field metabolic rate (FMR). However, due to the difficulties in measuring continuous behavior of birds over prolonged periods of time, complete time-activity budgets have rarely been examined in relation to FMR. Our objective was to determine the effect of activity (measured by detailed time-activity budgets) and a series of extrinsic and intrinsic factors on FMR of the omnivorous ring-billed gull (Larus delawarensis).

Methane baseline concentrations and sources in shallow aquifers from the shale gas-prone region of the St. Lawrence lowlands (Quebec, Canada).

Hydraulic fracturing is becoming an important technique worldwide to recover hydrocarbons from unconventional sources such as shale gas. In Quebec (Canada), the Utica Shale has been identified as having unconventional gas production potential. However, there has been a moratorium on shale gas exploration since 2010.

(222)Rn activity in groundwater of the St. Lawrence Lowlands, Quebec, eastern Canada: relation with local geology and health hazard.

One hundred ninety-eight groundwater wells were sampled to measure the (222)Rn activity in the region between Montreal and Quebec City, eastern Canada. The aim of this study was to relate the spatial distribution of (222)Rn activity to the geology and the hydrogeology of the study area and to estimate the potential health risks associated with (222)Rn in the most populated area of the Province of Quebec. Most of the groundwater samples show low (222)Rn activities with a median value of 8.