Groundwater-fed gravel pit lakes (GPLs) affect the biological, organic, and inorganic parameters of inflowing groundwater through combined effects of bank filtration at the inflow, reactions within the lake, and bank filtration at the outflow. GPLs result from wet dredging for sand and gravel and may conflict with groundwater protection programs by removing the protective soil cover and exposing groundwater to the atmosphere.

Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling (‘NEEM’) ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records.

We present a new mobile environmental reaction chamber for the simulation of the atmospheric aging of aerosols from different emissions sources without limitation from the instruments or facilities available at any single site. The chamber can be mounted on a trailer for transport to host facilities or for mobile measurements. Photochemistry is simulated using a set of 40 UV lights (total power 4 KW). Characterisation of the emission spectrum of these lights shows that atmospheric photochemistry can be accurately simulated over a range of temperatures from −7–25 °C.

Chemical weathering of rocks or sediments is extremely important for the generation of soils, for the evolution of landscape, and as a main source of inorganic nutrients for plant growth and therefore for life. Temporal trends in weathering mechanisms, plant succession and nutrients availability in cold environments can be successfully studied in soil chronosequences along a glacier forefield. In the present paper, this was carried out in the pro-glacial area of Morteratsch. Different forms of phosphorous in the soil, stream and spring water chemistry were investigated.

The stable isotopic compositions of nitrate dissolved in 49 types of bottled drinkingwater collected worldwide were determined, to trace the fate of atmospheric nitrate(NO−3 atm) that had been deposited into subaerial ecosystems, using the17O anomalies(∆175 O) of nitrate as tracers. The use of bottled water enables collection of groundwaterrecharged at natural, background watersheds. The nitrate in groundwater had small∆17O values ranging from −0.2 ‰ to +4.5 ‰ (n = 49).

Depth profiles were sampled at different locations throughout Lake Geneva on a monthly and seasonal basis over the course of two years and analyzed for their stable hydrogen and oxygen isotope compositions. The isotopic composition indicates an isotopic stratification in the metalimnion during summer and fall. This is related to mixing of Rhône River water, which in summer is dominated by snow and glacier melt waters, and lake water, with the latter having a homogenous isotopic composition.

The repeatability, reproducibility and accuracy of the direct measurement of δ(D) and δ(18O) isotopes inwater samples were evaluated using Cavity Ring-Down Spectrometry, and values comparable with the Isotopic Ratio Mass Spectrometry were obtained. Memory effect correction was negligible after five successive injections, and the time for each sample analysis was approximately 70 minutes. Application of the method toBrazilian bottled mineral water has shown that it is possible to trace the origin of the water to at least thestate level within Brazilian geographical regions.

 In this paper we report vertical profiles of CO₂ measured with a cavity ring-down spectrometer (CRDS, Picarro, Inc., 2301-m) on a research aircraft from near ground level to 8 km above mean sea level (a.m.s.l.). The airborne platform employed in this study is an Alpha Jet aircraft operated from NASA Ames Research Center. Flights were undertaken to Railroad Valley, Nevada, USA, to coincide with overpasses of the Greenhouse Gases Observing Satellite (GOSAT).

Deep saline aquifers are considered as the most promising option for geologic disposal of CO₂. One of the main concerns, however, is the integrity of the caprocks between and above the storage formations. Here, a hydrogeochemical and isotopic investigation is presented, using ionic chemistry, stable isotopes (δ¹⁸O, δ²H and ⁸⁷Sr/⁸⁶Sr) and radiocarbon dating, on five saline aquifers on a regional scale, namely: Neogene Minghuazhen, Guantao, Ordivician, Cambrian and Precambrian, all found in the Bohai Bay Basin in North China.

Accurate measurements of carbon monoxide (CO) in humid air have been made usingthe cavity ring-down spectroscopy (CRDS) technique. The measurements of CO molefractions are determined from the strength of its spectral absorption in the near infraredregion (∼ 1.57 µm) after removing interferences from adjacent carbon dioxide (CO25 )and water vapor (H2O) absorption lines. Water correction functions that account forthe dilution and pressure-broadening effects as well as absorption line interferencesfrom adjacent CO2 and H2O lines have been derived for CO2 mole fractions between360–390 ppm.

With the emergence of wide-spread application of cavity ring-down spectrometers (CRDS) to monitor δ¹³C in atmospheric CO₂ there is a growing need to ensure well calibrated measurements. We characterized a cavity ring-down spectrometer system used for continuous in-situ monitoring of atmospheric ¹³CO₂. We found no concentration dependency of the δ¹³C ratio within the range of 303–437 ppm.

Melting of the Greenland Ice Sheet (GrIS) is accelerating and will contribute signifi-cantly to global sea level rise during the 21st century. Instrumental data on GrIS melting only cover the last few decades, and proxy data extending our knowledge into5 the past are vital for validating models predicting the influence of ongoing climatechange. We investigated a potential meltwater proxy in Godthabsfjord (West Green- ˚land), where glacier meltwater causes seasonal excursions with lower oxygen isotopewater (δ18Ow) values and salinity.

In preparation for the routine deployment of the Earth Networks greenhouse gas monitoring network, we have designed and tested a simple method for drying ambient airto below 0.2 % mole fraction H2O using a Nafion dryer. The inlet was designed for usewith a Picarro model G2301 cavity ring down spectrometer (CRDS) CO2/CH45 /H2O analyzer. The analyzer measures water vapor mixing ratio at the same frequency as CO2and CH4 and then corrects for the dilution and peak broadening effects of H2O on theCO2 and CH4 mixing ratios.

This article reports the first application of coupled total organic carbon cavity ring-down spectroscopy (TOC-CRDS) for the analysis of the δ¹³C signature of dissolved organic carbon (DOC) in freshwater samples. DOC represents a major, dynamic component of the global carbon cycle. The export of DOC from soils into rivers and groundwaters may be highly climate sensitive, and much of this export may occur in ephemeral fluxes. Thus, a robust, simple and inexpensive method for the continuous determination of DOC concentration and quality is urgently needed.

Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water), long-term tropospheric water vapour isotopologues data records are provided for ten globally distributed ground-based mid-infrared remote sensing stations of the NDACC (Network for the Detection of Atmospheric Composition Change). We present a new method allowing for an extensive and straightforward characterisation of the complex nature of such isotopologue remote sensing datasets.

The Total Carbon Column Observing Network (TCCON) is a ground-based network of Fourier Transform Spectrometer (FTS) sites around the globe, where the column abundances of CO₂, CH₄, N₂O, CO and O₂ are measured. CO₂ is constrained with a precision better than 5 0.25%. To achieve a similarly high accuracy, calibration to World Meteorological Organization (WMO) standards is required. This paper introduces the first aircraft calibration campaign of five European TCCON sites and a mobile FTS instrument.

N₂ fixation by moss-associated cyanobacteria plays an important role in the nitrogen cycling of terrestrial ecosystems. Recent studies have mainly focused on boreal ecosystems; little is known about such association in other ecosystems. Moss-associated cyanobacteria are subject to rapid changes (hourly or less) in environmental conditions that may affect N₂fixation kinetics.

By employing chemical and isotopic tracers (¹⁵N and ¹⁸O in NO₃⁻), we investigated the main processes controlling nitrate distribution in the unsaturated zone and aquifer. Soil water was extracted from two soil cores drilled in a typical agricultural cropping area of the North China Plain (NCP), where groundwater was also sampled. The results indicate that evaporation and denitrification are the two major causes of the distribution of nitrate in soil water extracts in the unsaturated zone.

The 2010 Arctic Mars Analog Svalbard Expedition (AMASE) investigated two distinct geologic settings on Svalbard, using methodologies and techniques to be deployed on Mars Science Laboratory (MSL). AMASE-related research comprises both analyses conducted during the expedition and further analyses of collected samples using laboratory facilities at a variety of institutions.

We examined potential interferences from water vapor and atmospheric backgroundgases (N2, O2, and Ar), and biases by isotopologues of target species, on accuratemeasurement of atmospheric CO2 and CH4 by means of wavelength-scanned cavity5 ring-down spectroscopy (WS-CRDS). Variations in the composition of the backgroundgas substantially impacted the CO2 and CH4 measurements: the measured amounts ofCO2 and CH4 decreased with increasing N2 mole fraction, but increased with increasing O2 and Ar, suggesting that the pressure-broadening effects (PBEs) increased asAr < O2 < N2.

The NorthGRIP ice core chronology GICC05modelext is composed of the annual-layercounted GICC05 chronology to 60 kyr before 2000 AD (b2k), and an ice flow model dating the deepest part of the ice core to 123 kyr b2k. Determination of annual strata in ice5 beyond 60 kyr b2k has been challenged by the thinning of annual layers to < 1 cm andthe appearance of microfolds in some early glacial strata.

Mountain–plain transitional landscapes are especially important as groundwater recharge zones. In this study, the oxygen and hydrogen stable isotopic composition (δ¹⁸O and δD) of water and hydrochemical information were employed to quantify contribution ratios of different sources of groundwater recharge in the Ashikaga area of central Japan. The study area is situated between the Ashio Mountains and the Kanto Plain, and the Watarase River flows into the region parallel to the mountain–plain boundary.

Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. However,the current data quality objectives of the World Meteorological Organization (WMO) for5 carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, newspectroscopic techniques came on the market with promising properties for trace gasanalytics.

The presence of aqueously altered, olivine-rich rocks along with carbonate on Mars suggest that serpentinization may have occurred in the past and may be occurring presently in the subsurface, and possibly contributing methane (CH₄) to the martian atmosphere. Serpentinization, the hydration of olivine in ultramafic rocks, yields ultra-basic fluids (pH ⩾ 10) with unique chemistry (i.e. Ca²⁺–OH⁻ waters) and hydrogen gas, which can support abiogenic production of hydrocarbons (i.e.

The D/H isotope ratio is used to attribute boundary layer humidity changes to the set of contributing fluxes for a case following a snowstorm in which a snow pack of about 10 cm vanished. Profiles of H₂O and CO₂ mixing ratio, D/H isotope ratio, and several thermodynamic properties were measured from the surface to 300 m every 15 min during four winter days near Boulder, Colorado.

Combined measurements of salinity and the oxygen/hydrogen stable isotope composition of marine
waters can characterise processes such as freshwater mixing, evaporation, precipitation and sea-ice formation.
However, stable isotope data with high spatial and temporal resolution are necessary for a detailed understanding
of mixed water bodies with multiple inputs. So far analysis of d18O and dD values in water has been a relatively
expensive, laboratory-based technique requiring collection of discrete samples. This has greatly limited the scope and

A 141 m-long ice core was recovered from Combatant  Col (51.385°N, 125.258°W, 3000 m a.s.l.), Mount Waddington, Coast Mountains, British Columbia, Canada.  Records of black carbon, dust, lead, and water stable-isotopes demonstrate that unambiguous seasonality is preserved throughout the core, despite summer surface snowmelt and temperate ice. High accumulation rates at the site (in excess of 4 m a-1ice-equivalent) limit modification of annual stratigraphy by percolation of surface meltwater. The ice-core record spans the period 1973-2010.

A one hour integrated flask sampling system to collect air in automated NOAA/ESRL12-flask packages is described. The integrating compressor system uses a mass flowcontroller to regulate the flow of air through a 15 l volume, thus providing a mixture of air5 collected over an hour-long period. By beginning with a high flow rate of 3800 standardliters per minute and gradually decreasing the flow rate over time to 290 standardliters per minute it is possible to obtain a nearly uniformly time averaged sample of airand collect it into a pressurized 0.7 l flask.

The repeatability, reproducibility and accuracy of the direct measurement of δ(D) and δ(¹⁸O) isotopes in water samples were evaluated using Cavity Ring-Down Spectrometry, and values comparable with the Isotopic Ratio Mass Spectrometry were obtained. Memory effect correction was negligible after five successive injections, and the time for each sample analysis was approximately 70 minutes.

There is a close relationship between surface water and groundwater in semi-arid and arid areas of China, and thus researching on the interactions of them is of importance for reasonable water resources development. This paper took Bulang River basin as case study, analysis and discussion were conducted to water chemistry and isotopes tests results of water samples. The results show that surface water in Bulang River basin mainly relies on precipitation recharge, partially on groundwater recharge, the hydrochemistry type of surface water is mainly Ca-HCO₃ with low salinity.

Tunable diode laser absorption (TDL) and cavity ring-down spectroscopic (CRDS) sensors for atmospheric  carbon dioxide were co-deployed during summer and fall of 2010 in field and laboratory conditions at Los Alamos National Laboratory. Both sensors were characterized for accuracy and precision for ambient carbon dioxide measurements at ground level and compared using both laboratory and ambient field data.

Isotope records of atmospheric CH₄ can be used to infer changes in the biochemistry of CH₄. One factor limiting quantitative estimates of changes in the biogeochemistry of CH₄ are the uncertainties of the isotope measurements due to the lack of a unique isotope reference gas, certified for ¹³C-CH₄ or ² 5 H-CH₄.

The experiment was conducted at twelve grazing plots denoting four treatments defined along a grazing gradient with three replications: non-grazing (0 sheep/ha, NG), light grazing (0.75 sheep/ha, LG), moderate grazing (1.50 sheep/ha, MG) and heavy grazing (2.25 sheep/ha, HG). Using an automatic cavity ring-down spectrophotometer, we measured CH₄ fluxes from March 1 to April 29 in 2010 and March 2 to April 27 in 2011.

A new technique for the satellite remote sensing of greenhouse gases in the atmosphere via the absorption of short-wave infrared laser signals transmitted between counter-rotating satellites in low earth orbit has recently been proposed; this would enable the acquisition of a stable, global set of altitude-resolved concentration measurements.

Hydrogen isotope ratios in lipids derived from mangroves have the potential to be used for paleohydrologic reconstructions and could serve as a much needed tool for establishing past climate variability in the tropics. We assessed the effect of salinity on the apparent fractionation factor, α_a, between mangrove derived n-alkanes and their source water for Avicennia marina (gray mangrove) specimens collected along a 28 PSU salinity gradient in the Brisbane River Estuary.

Attributing observed CO₂ variations to human or natural cause is critical to deducing and tracking emissions from observations. We have used in situ CO₂, CO, and planetary boundary layer height (PBLH) measurements recorded during the CalNex-LA (CARB et al., 2008) ground campaign of 15 May–15 June 2010, in Pasadena, CA, to deduce the diurnally varying anthropogenic component of observed CO₂ in the megacity of Los Angeles (LA).

The lapse rate of water isotopes is used in the study of the hydrologic cycle as well as in the estimation of uplift of the Tibetan Plateau. The greater elevation contrast in the southern Himalayas allows for a detailed discussion about this lapse rate. We analyze variations of δ ¹⁸O in precipitation and river water between 1320 m and 6700 m elevations in the southern Himalayas, and calculate the specific lapse rate of water δ ¹⁸O.

Variations of stable water isotopes in water vapour have become measurable at a measurement frequency of about 1 Hz in recent years using novel laser spectroscopic techniques. This enables us to perform continuous measurements for process-based investigations of the atmospheric water cycle at the time scales relevant for synoptic meteorology. An important prerequisite for the interpretation of data from automated field measurements lasting for several weeks or months is a detailed knowledge about instrument properties and the sources of measurement uncertainty.

The suite of measurement methods available to characterize fluxes between groundwater and surface water is rapidly growing. However, there are few studies that examine approaches to design of field investigations that include multiple methods. We propose that performing field measurements in a spatially telescoping sequence improves measurement flexibility and accounts for nested heterogeneities while still allowing for parsimonious experimental design.

Questions of mobility, settlement pattern, and their relation to economic organization and resource use are central to ongoing work in central-western Argentina. Here we analyze geographic patterns in the distribution of 178 human bone carbonate δ¹⁸O samples, 46 human tooth enamel carbonate δ¹⁸O samples, and 48 water δ¹⁸O samples from throughout the Andean Cordillera and Monte Desert and evaluate their implications for prehistoric mobility and economy.

Soil and vadose zone profiles are used as an archive of changes in groundwater recharge and water quality following changes in land use in an area of the Loess Plateau of China. A typical rain-fed loess-terrace agriculture region in Hequan, Guyuan, is taken as an example, and multiple tracers (chloride mass balance, stable isotopes, tritium and water chemistry) are used to examine groundwater recharge mechanisms and to evaluate soil water chloride as an archive for recharge rate and water quality.

RATIONALE:

The Amazon River is a huge network of long tributaries, and little is known about the headwaters. Here we present a study of one wet tropical Amazon forest side, and one dry and cold Atiplano plateau, originating from the same cordillera. The aim is to see how this difference affects the water characteristics.

The traditional hypothesis that old-growth forests are carbon neutral is under debate as recent studies show evidence of net carbon sequestration. Here, we present a decade (1998–2008) of carbon dioxide, water and energy fluxes from an old-growth stand in the American Pacific Northwest to identify ecosystem-level responses to climate variability, including teleconnection patterns. This study provides the longest, continuous record of old-growth eddy flux data to date.

Background. The diffusion of high-performance analytical technology has opened prospects for breath diagnosis as a non-invasive diagnostic tool. In this study, ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques were used to analyse ammonia gas (NH3) in real-time in breath from patients undergoing haemodialysis (HD) treatment and any correlation with blood urea nitrogen (BUN) levels and Kt/V were investigated.

The mechanisms allowing the rapid release of stored water to streams are poorly understood. Here we use a tile drained field site to combine naturally structured soils at the hillslope scale with the advantage of at least partly controlled lower boundary conditions. We performed a series of three irrigation experiments combining hydrometric measurements with stable isotope and bromide tracers to better understand macropore-matrix interactions and stored water release processes at the hillslope scale.