Field tests of a new WS-CRDS based, closed-path analyzer for simultaneous eddy covariance flux measurements of CO2 and methane.
Describes field testing of Picarro's fast analyzer for eddy covariance flux measurements of greenhouse gases.
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.
The quantification of fugitive methane emissions from extended sources such as landfills is problematic due to the high temporal variability and spatial heterogeneity of the emission. Additionally, the relationship between the emission rate and the gas concentration at a given location is dependent on the meteorological conditions and local topography, preventing accurate quantification of…
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.
Describes a field campaign wherein a Picarro water isotope analyzer was used to measure isotopes in water vapor over a corn field in China for the purpose of studying evapotranspiration. The Picarro sampled vapor along with a cold trap sampling system and the real-time Picarro data was compared to offline analysis of the trapped vapor.
The regulation of Earth’s climate and its ability to sustain life are critically linked to water as it exists in all three of its phases (gas, liquid, and solid). Earth’s water cycle, its movement between the hydrosphere, biosphere, and the atmosphere, and how it undergoes phase changes, is incredibly complex. While we continue to gain insight into the water cycle, there remains…
Cavity Ring-Down spectroscopy is becoming a gold standard for atmospheric monitoring. High sensitivity and precision coupled with low drift characteristics ensure optimal operation even in remote field stations or on aircraft and ships. However, current platforms have been limited to two or three species simultaneous observation. Research and development at Picarro have been focused on…
Hydrothermal fluids from two vent sites along the East Scotia Ridge, E2 and E9, were analyzed for their hydrogen and oxygen isotopic values using a Picarro L1115-i CRDS. The fluids display varying salinity, sulfate and hydrogen sulfide content. None of the samples analyzed in this work showed any signs of spectroscopic interference. Isotopic values of the fluids were combined with…
The world’s first continuous flow isotopic TIC/DOC-CRDS measurements are reported here with remarkable achieved precisions. A measurement precision of the isotopic ratio in the range of 0.2 ‰ to 0.4 ‰ was achieved in minutes of measurement time. Such precision readily distinguishes the isotopic DIC and DOC signatures from a set of three different streamwater samples collected from various…
The recent development of a field deployable water isotope analyzer using CRDS technology was used to directly measure the vapor isotopes in real time and at multiple heights above the crop canopy. This technique was coupled with additional samples gathered using conventional techniques and a new xylem water extracting apparatus developed by the IAEA.
In a paper published by the Integrated Carbon Observation System (ICOS), the drift performance of 47 Picarro analyzers of 3 different generations were compared (Yver Kowket al, Atmos. Meas. Tech. Discuss., 8, 4219–4272, 2015). The results show that methane drift (the minimum of the Allan standard deviation) was much better in first-generation G1000 analyzers.
…High-salinity waters such as Seawater poses an operational and maintenance challenge to the measurements of water stable isotopes via Cavity Ring-Down Spectroscopy. As liquid samples are evaporated in the vaporizer peripheral before being sent to the CRDS analyzer, salt precipitates accumulate in the vaporizer chamber. As a result, the sample-to-sample memory performance degrades over time…
Soil flux chamber measurements are a key tool for determining production and sequestration of direct and indirect greenhouse gases. The Picarro G2508 Cavity Ring-down Spectrometer radically simplifies soil flux analyses by providing simultaneous measurements of five gases: CO2, CH4, N2O, NH3, and H2O, and by ready field deployment. The Picarro Soil Flux Software (SFP) …
With a global warming potential of nearly 300, N2O is a critically important greenhouse gas, contributing about 5 % of the US total GHG emissions. Agriculture soil management practices are the dominant source of anthropogenic N2O emissions, contributing nearly 75 % of US N2O emissions. In urban areas, vehicle tailpipe emissions and waste water treatment plants are…
The necessity for constant monitoring of greenhouse gases (GHGs) is clearly evident now more than ever. Moreover, interpreting and understanding the processes that dictate the production and consumption of these gases will allow for proper management of GHGs in order to mitigate its detrimental climate effects. Presence of oxygen, or lack of it, is the driving force for determining pathways…
High-accuracy continuous measurements of greenhouse gases (CO2 and CH4) during the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) phase B campaign in Brazil in May 2009 were accomplished using a newly available analyzer based on the cavity ring-down spectroscopy (CRDS) technique. This analyzer was flown without a drying system or any in-flight…
Horizontal drilling and hydraulic fracturing are transforming energy production, but their potential environmental effects remain controversial. We analyzed 141 drinking water wells across the Appalachian Plateaus physiographic province of northeastern Pennsylvania, examining natural gas concentrations and isotopic signatures with proximity to shale gas wells. Methane was detected in 82% of…
The doubly labeled water method provides an objective and accurate measure of total energy expenditure in free-living subjects and is considered the gold-standard method for this measurement. Its use, however, is limited by the need to employ isotope ratio mass spectrometry (IRMS) to obtain the high-precision isotopic abundance analyses needed to optimize the dose of expensive 18…
The Deepwater Horizon oil spill was unprecedented in total loading of petroleum hydrocarbons accidentally released to a marine ecosystem. Controversial application of chemical dispersants presumably accelerated microbial consumption of oil components, especially in warm Gulf of Mexico surface waters. We employed δ13C as a tracer of oil-derived carbon to resolve two periods of…
Methane was the most abundant hydrocarbon released during the 2010 Deepwater Horizon oil spill in the Gulf of Mexico. Beyond relevancy to this anthropogenic event, this methane release simulates a rapid and relatively short-term natural release from hydrates into deepwater. Based on methane and oxygen distributions measured at 207 stations throughout the affected region, we find that within…
Bats are one of the most successful mammalian groups, even though their foraging activities are restricted to the hours of twilight and night-time. Some studies suggested that bats became nocturnal because of overheating when flying in daylight. This is because—in contrast to feathered wings of birds—dark and naked wing membranes of bats efficiently absorb short-wave solar radiation. We…
We investigated the moisture origin and contribution of different water sources to surface runoff entering the headwaters of the Heihe River basin on the basis of NECP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) re-analysis data and variations in the stable hydrogen and oxygen isotope ratios (δD and δ18O) of…
Direct quantification of fossil fuel CO2 (CO2ff) in atmospheric samples can be used to examine several carbon cycle and air quality questions. We collected in situ CO2, CO, and CH4 measurements and flask samples in the boundary layer and free troposphere over Sacramento, California, USA, during two aircraft flights over…
Monitoring is essential for the approval and control of geological storage of carbon dioxide and to judge the effectiveness of the technology in mitigating CO2 emissions and climate change. We present a strategy for monitoring the atmosphere in the vicinity of a geological storage project that is designed to detect and quantify potential emissions. The strategy includes…
CO2 was injected into a coal fire burning at a depth of 15 m in the subsurface in southwestern Colorado, USA. Measurements were made of the 13CO2 isotopic signature of gas exhaust from an observation well and two surface fissures. The goal of the test was to determine (1) whether CO2 with a distinct isotopic signature could be used as a tracer to…
A portable stable carbon isotope ratio analyzer for carbon dioxide, based on wavelength scanned cavity ringdown spectroscopy, has been used to detect, locate, and characterize an intentional leakage of CO2 from an underground pipeline at the ZERT experimental facility in Bozeman, Montana. Rapid (1 h) walking surveys of the 100 m x 100 m site surrounding the…
The potential of a continuous wave cavity ringdown spectrometer for monitoring the isotope ratio 13CO2/12CO2 and the partial pressure pCO2 of CO2 dissolved in water was thoroughly analyzed by quantitative measurements. Running calibration gas standards under typical operation conditions, a elative accuracy of D(d13C[CO2]) = ±0.1‰…
We used metabolic tracers and modeling to analyze the response of soil metabolism to a sudden temperature change from 4 to 20 °C. We hypothesized that intact soil microbial communities would exhibit shifts in pentose phosphate pathway and glycolysis activity as observed for individual microorganisms in pure culture, and that increased maintenance respiration at…
The hydrogen and oxygen isotope ratios of water vapor can be measured with commercially available laser spectroscopy analyzers in real time. Operation of the laser systems in relatively dry air is difficult because measurements are non-linear as a function of humidity at low water concentrations. Here we use field-based sampling coupled with traditional mass spectrometry techniques for…
For anchoring CO2 isotopic measurements on the δ18OVPD-CO2 scale, the primary reference material (NBS 19 calcite) needs to be digested using concentrated ortho-phosphoric acid. During this procedure, great care must be taken to ensure that the isotopic composition of the liberated gas is accurate. Apart from controlling the reaction temperature to ±0.1°C, the potential for oxygen isotope…
We used metabolic tracers and modeling to analyze the response of soil metabolism to a sudden temperature change from 4 to 20 °C. We hypothesized that intact soil microbial communities would exhibit shifts in pentose phosphate pathway and glycolysis activity as observed for individual microorganisms in pure culture, and that increased maintenance respiration at higher temperature would…
Cavity ring-down spectroscopy (CRDS) is a new and evolving technology that shows great promise for isotopic δ(18)O and δ(2)H analyses of pore water from equilibrated headspace H(2)O vapor from environmental and geologic cores. We show that naturally occurring levels of CH(4) can seriously interfere with CRDS spectra, leading to erroneous δ(18)O and δ(2)H results for water. We created a new…
A new technique for high-resolution simultaneous isotopic analysis of δ18O and δD in liquid water is presented. A continuous stream flash evaporator has been designed that is able to vapourise a stream of liquid water in a continuous mode and deliver a stable and finely controlled water vapour sample to a commercially available infrared cavity ring-down spectrometer.…
A new technique for on-line high resolution isotopic analysis of liquid water, tailored for ice core studies is presented. We built an interface between a Wavelength Scanned Cavity Ring Down Spectrometer (WS-CRDS) purchased from Picarro Inc. and a Continuous Flow Analysis (CFA) system. The system offers the possibility to perform simultaneuous water isotopic…
Over the last century, many grasslands worldwide have transitioned from a graminoid to atree/shrub-dominated state in a short period of time, a phenomenon referred to as woody encroachment.Positive feedbacks and bi-stability are thought to be important drivers of woody encroachment, but there islittle empirical evidence to suggest that positive feedbacks accelerate the woody encroachment of…