We provide sedimentological, geochemical, mineral magnetic, stable carbon isotope, charcoal, and pollen-based evidence from a guano/clay sequence in Gaura cu Muscă Cave (SW Romania), from which we deduced that from ~ 1230 BC to ~ AD 1240 climate oscillated between wet and dry. From ~ 1230 BC to AD 1000 the climate was wetter than the present, prompting flooding of the…
Here we test an experimental approach that produces estimates of the location, timing and extent of water uptake by individual plant species in the field. A tracer injection experiment was used to estimate the proportion of active roots across soil depths. These proportions were multiplied by species-specific estimates of evapotranspiration. This approach was repeated in early- and…
With the recent advent of commercial laser absorption spectrometers, field studies measuring stable isotope ratios of hydrogen and oxygen in water vapor have proliferated. These pioneering analyses have provided invaluable feedback about best strategies for optimizing instrumental accuracy, yet questions still remain about instrument performance and calibration approaches for multi-…
The performance of eight fast-response methane (CH4) gas analysers suitable for eddy covariance flux measurements were tested at a grassland site near the Cabauw tall tower (Netherlands) during June 2012. The instruments were positioned close to each other in order to minimise the effect of varying turbulent conditions. The moderate CH…
A laboratory and field experiment compared fluxes of CO2 , CH4 and N2O measured with cavity ring-down spectroscopy (CRDS) and gas chromatography (GC). The comparison between CRDS and GC showed that average CO2 fluxes were significantly higher for CRDS in both the…
Coastal wetlands are commonly exposed to hydrocarbon pollutants derived from extraction disasters like the Deepwater Horizon oil spill. Naturally occurring microbes can degrade oil, but the rate of oil degradation depends heavily on the key chemical and biological factors. The goal of this study was to…
Methane is emitted to the atmosphere from both anthropogenic and natural sources. One of the major anthropogenic sources is methane produced by bacteria in anaerobic environments such as rice pads and landfills. Land filling has for many years been the preferred waste disposal method, resulting in a large methane production with a large contribution to the global increase in…
Methane is a greenhouse gas (GHG) and the anthropogenic emission of methane to the atmosphere contributes to global warming. There are several anthropogenic methane sources, and the quantification of methane from these emission sources are often based on emission factors and model calculations making reporting uncertain. Reducing the methane emission is an effective way of reducing the…
Production of natural gas from shale formations is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past, which has generated considerable interest in potential environmental impacts. This study focused on the Barnett Shale Fort Worth Basin in Texas, which saw the number of gas-producing wells…
The most common currency for estimating N2 fixation is acetylene reduction to ethylene. Real-time estimates of nitrogen fixation are needed to close the global nitrogen budget and these remain a critical gap in both laboratory and field experiments. We present a new method for continuous real-time measurements of ethylene production: Acetylene Reduction Assays by Cavity ring-down…
Laser spectroscopy is an emerging technology for measuring nitrous oxide (N2O) dynamics in the environment, but most studies have focused on atmospheric applications. We have coupled a commercially available cavity ring-down spectroscope (CRDS) (Picarro G5101-i isotopic N2O analyzer) to an air/water gas…
We present a novel determination of the dissolution kinetics of inorganic calcite in seawater. We dissolved 13C-labeled calcite in unlabeled seawater, and traced the evolving …
Automated in situ instrumentation captured high-resolution surface water pCO2, CH4 and222Rn data at the creek mouth, and ∼500 m upstream in a sub-tropical mangrove ecosystem (Southern Moreton Bay, Australia, S27.78°, E153.38°) over a spring-neap-spring tidal cycle (∼15 …
Estuaries have high rates of primary production and respiration and can be hotspots for carbon dioxide and methane enriched submarine groundwater discharge. Here, we report high resolution pCO2, CH4, δ13C–CO2, δ13C–CH4…
Automated cavity ring down spectroscopy was used to make continuous measurements of dissolved methane, nitrous oxide, and carbon dioxide in a coral reef lagoon for 2 weeks (Heron Island, Great Barrier Reef). Radon (222Rn) was used to trace the influence of tidally driven pore water exchange on greenhouse gas dynamics. Clear tidal variation was…
Floods frequently produce deoxygenation and acidification in waters of artificially drained coastal acid sulfate soil (CASS) wetlands. These conditions are ideal for carbon dioxide and methane production. We investigated CO2 and CH4 dynamics and quantified carbon loss within an artificially drained CASS wetland during and after a flood. We separated the…
Fugitive greenhouse gas emissions from unconventional gas extraction processes (e.g. shale gas, tight gas and coal bed methane/coal seam gas) are poorly understood due in part to the extensive area over which these emissions may occur. We apply a rapid qualitative approach for source assessment at the scale of a large gas field. A mobile cavity ring down spectrometer (Picarro G2201-…
The replacement of native species by invasive Phragmites australis in coastal wetlands may impact ecosystem processes including fluxes of the greenhouse gases (GHGs) carbon dioxide (CO2) and methane (CH4). To investigate differences in daytime CH…
We present a study of methane emissions from oil and gas producing well pad facilities in the Barnett Shale region of Texas, measured using an innovative ground-based mobile flux plane (MFP) measurement system, as part of the Barnett Coordinated Campaign. Using only public roads, we measured the emissions from nearly 200 well pads over 2 weeks in October 2013. The population of…
This study presents two methods for estimating methane emissions from a waste water treatment plant (WWTP) along with results from a measurement campaign at a WWTP in Valence, France. These methods, chamber measurements and tracer release, rely on Fourier transform infrared spectroscopy and cavity ring-down spectroscopy instruments. We show that the tracer release method is suitable…
A portable Wavelength Scanned-Cavity Ring-Down Spectrometer (Picarro L2120) fitted with a diffusion sampler (DS-CRDS) was used for the first time to continuously measure δ18O and δ2H of stream water. The experiment took place during a storm event in a wet tropical agricultural catchment in north-eastern Australia. At a temporal…
Temperature reconstructions across Heinrich stadials 1–3 are presented from an absolute-dated speleothem from Abaco Island in the Bahamas to understand the nature of climate change across these intervals in the subtropical Atlantic. The stalagmite carbonate record, dated by the U–Th geochronometry technique, includes higher δ18O and …
Insights into the effects of stormwater control measures (SCMs) on urban stream hydrology and in-stream processes are required to understand their effectiveness in mitigating the environmental problems associated with urbanization. Stable water isotopes were applied to understand processes occurring within SCMs and their effects on water sourcing in urban streams. We sampled ten…
The isotopic composition of near surface (or planetary boundary layer) water vapor on the south coast of Iceland (63.83°N, 21.47°W) has been monitored in situ between November 2011 and April 2013. The calibrated data set documents seasonal variations in the relationship between δ18O and local humidity (ppmv) and between deuterium…
Laser-based spectroscopic techniques, such as cavity ring-down spectroscopy (CRDS), provide a new, costeffective and more widely available approach to measure the oxygen isotope ratio in water molecules, H218O/H216O (d18O), and are used increasingly to measure d18O in the world’s oceans. Here, we present results froman interlaboratory comparison designed to evaluate the quality of…
Deuterium (dD) and oxygen (d18O) isotopes are powerful tracers of the hydrological cycle and have been extensively used for paleoclimate reconstructions as they can provide information on past precipitation,temperature and atmospheric circulation. More recently, the use of 17O excess derived from precise measurement of d17O and d18O gives new and additional insights in tracing the…
A laboratory and field experiment compared fluxes of CO2, CH4 and N2O measured with cavity ring-downspectroscopy (CRDS) and gas chromatography (GC). The comparison between CRDS and GC showed thataverage CO2 fluxes were significantly higher for CRDS in both the laboratory and field, but the same experimental treatments effects were detected for…
A correction for the undesirable effects of direct and indirect cross-interference from water vapour on ammonia (NH3) measurements was developed using an optical laser sensor based on cavity ring-down spectroscopy. This correction relied on new measurements of the collisional broadening due to water vapour of two NH3 spectral…
Describes development of and results obtained from an analyzer engineered by Picarro for measuring six important atmospheric contaminants (hydrogen sulfide, ammonia, nitrous oxide, carbon dioxide, water vapor and methane) that are of interest to researchers monitoring Concentrated Animal Feeding Operations (CAFOs).
Picarro has developed a field-deployable, real time, ambient gas monitor capable of measuring atmospheric levels of carbon dioxide, methane, hydrogen sulfide, and ammonia with parts-per-billion (ppbv) sensitivity and water vapor with parts-per-million (ppmv) sensitivity. Results from field trials of three different CO2 analyzers at Harvard, Penn State, and the NOAA facility in Boulder CO…
Description of field-deployable instrumentation that measures carbon dioxide, methane, and water vapor with both high-accuracy and high-precision would reduce the uncertainty in the determination of terrestrial sources and sinks of these dominant greenhouse gases.
Results presented from field trials at Woods Hole Oceanographic Institute and laboratory tests at INSTAAR of a newly available analyzer capable of performing continuous measurements of stable isotopes (δD and δ18O) of liquid water and / or water vapor samples.
Picarro has developed an isotope analyzer for lab and field measurements of carbon isotopes in CO2 with the goal of allowing turnkey analysis to be done without the need for flask samples and complex IRMS methods. Here we present a description of the analyzer and its technology as well as recent results from two different collaborators who utilized the analyzer.
Describing work by CSIRO, CO2 CRC and Picarro to characterize sequestration site leaks using tracers and isotopes.
Describes the first field data taken by Oregon State University of Picarro's dual-species Eddy-Covariance analyzer.
Describes work by INSTAAR, NOAA & Picarro on both liquid water and water vapor measurements of stable water isotopes.
From the EGU 2009 General Assembly, describing measurements of edible oils and chocolates made with Picarro's iTOC-CRDS Isotopic Carbon Analyzer.
Describes specific design aspects of WS-CRDS-based analyzers and how these details result in ultra-stable field measurements.
Describes how CRDS works and shows hydrogen, oxygen and carbon isotope data for water vapor, evapotranspiration, food and agricultural applications.
Describes liquid water and water vapor isotope measurements with the Picarro isotopic water analyzer.
Describes field testing of Picarro's fast analyzer for eddy covariance flux measurements of greenhouse gases.
Describes results of laboratory testing and field campaigns with Picarro's flight-ready greenhouse gas analyzer.
Describes results from a Picarro N2O analyzer based in the mid-infrared spectral region.
Describes a newly-developed analyzer for tracer-based measurements and shows results from field work using such a system.
Describes recent developments in GC-C-CRDS-based instrumentation applied to isotope measurements in large molecules.
Describes the flexibility of Picarro's fast water isotope analyzer for applications requiring very short sample-to-sample measurement times and shows data taken in lab and field measurements.
Describes recent developments in CRDS instrumentation in the mid-infrared spectral region for applications using N2O isotopologue and trace concentration measurements.
Describes field work conducted with Picarro water isotope analyzer for both water vapor and liquid water samples.
Describes use and methods for stable isotope-based food adulteration testing using Cavity Ring-Down Spectrometry.
Describes application and function of a the LIAISON, a new Picarro universal interface for high throughput analysis.
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