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董事会 - Cloned
Alex Balkanski
Picarro 总裁兼首席执行官
Alex Balkanski 是一位卓越的长期行业领导者，在提高收入和利润方面有着丰富的经验，同时也获得了客户满意度的认可。在 2013 年 11 月加入 Picarro 担任总裁兼首席执行官之前，Alex 是 Benchmark 的管理合伙人，并担任 Picarro 董事会成员。Alex 曾经领导 C-Cube 和 DiviCom，这两家公司推动了 MPEG 标准在消费电子和广播领域占据主导地位。Alex 于 1988 年创立了 C-Cube。1994 年，他将公司成功上市，并于 1998 年策划了 C-Cube 对 DiviCom 的收购。此前，他是 Ambarella（AMBA），Decru（被 Network Appliance 收购），Entrisphere（…
董事会 - Cloned
Alex Balkanski
Picarro 总裁兼首席执行官
Alex Balkanski 是一位卓越的长期行业领导者，在提高收入和利润方面有着丰富的经验，同时也获得了客户满意度的认可。在 2013 年 11 月加入 Picarro 担任总裁兼首席执行官之前，Alex 是 Benchmark 的管理合伙人，并担任 Picarro 董事会成员。Alex 曾经领导 C-Cube 和 DiviCom，这两家公司推动了 MPEG 标准在消费电子和广播领域占据主导地位。Alex 于 1988 年创立了 C-Cube。1994 年，他将公司成功上市，并于 1998 年策划了 C-Cube 对 DiviCom 的收购。此前，他是 Ambarella（AMBA），Decru（被 Network Appliance 收购），Entrisphere（…
PI5310 – 大气 N2O 和 CO 监测的解决方案
在全球致力于理解和应对气候变化的过程中，全球各地的网络正在监测温室气体（GHGs）。Picarro 分析仪凭借其独特的高精度 CRDS 技术，被广泛应用于包括所有欧洲综合碳监测系统（ICOS）大气主题中心（ATC）网络在内的许多监测网络中。随着 PI5310 氧化亚氮（N2O）和一氧化碳（CO）分析仪的推出，Picarro 提供了符合并超越世界气象组织（WMO）兼容性目标和 ICOS 规格要求的 N2O 和 CO 大气监测的最佳解决方案。
为什么要监测N2O
二氧化碳（…
Isotopic evidence for the moisture origin and composition of surface runoff in the headwaters of the Heihe River
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…
Assessment of fossil fuel carbon dioxide and other anthropogenic trace gas emissions from airborne measurements over Sacramento, California in spring 2009
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…
Atmospheric monitoring of the CO2 CRC Otway Project and lessons for large scale CO2 storage projects
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…
Real-Time Tracking of CO2 Injected into a Subsurface Coal Fire through High-Frequency Measurements of the 13CO2 Signature
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…
Rapid detection and characterization of surface CO2 leakage through the real-time measurement of δ13 C signatures in CO2 flux from the ground
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…
Toward continuous monitoring of seawater 13CO2/12CO2 isotope ratio and pCO2: Performance of cavity ringdown spectroscopy and gas matrix effects
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‰…
Effect of temperature on metabolic activity of intact microbial communities: Evidence for altered metabolic pathway activity but not for increased maintenance respiration and reduced carbon use efficiency
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…
Probing carbon flux patterns through soil microbial metabolic networks using parallel position-specific tracer labeling
In order to study controls on metabolic processes in soils, we determined the dynamics of 13CO2 production from two position-specific 13C-labeled pyruvate isotopologues in the presence and absence of glucose, succinate, pine, and legume leaf litter, and under anaerobic conditions. We also compared 13CO2…
Hydrogen isotope correction for laser instrument measurement bias at low water vapor concentration using conventional isotope analyses: application to measurements from Mauna Loa Observatory, Hawaii
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…
δ18O anchoring to VPDB: calcite digestion with 18O-adjusted ortho-phosphoric acid
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…
Modeling soil metabolic processes using isotopologue pairs of position-specific 13C-labeled glucose and pyruvate
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…
Correcting for Methane Interferences on δ2H and δ18O Measurements in Pore Water Using H2O(liquid)–H2O(vapor) Equilibration Laser Spectroscopy
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 continuous stream flash evaporator for the calibration of an IR cavity ring-down spectrometer for the isotopic analysis of water
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.…
Water isotopic ratios from a continuously melted ice core sample
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…
Positive feedbacks amplify rates of woody encroachment in mesic tallgrass prairie
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…
Exploring Geographic Origins at Cahuachi using Stable Isotopic Analysis of Archaeological Human Tissues and Modern Environmental Waters
In this study, we used oxygen- and hydrogen-isotope data from human bone (δ18O) and modern environmental water samples (δ18O and δD) to investigate geographic origins of individuals buried at Cahuachi, a ceremonial centre in the Nasca region of Peru (c.AD1-1000). Our objective was to characterise the natural variation in water stable…
Properties of air mass mixing and humidity in the subtropics from measurements of the D/H isotope ratio of water vapor at the Mauna Loa Observatory
Water vapor in the subtropical troposphere plays an important role in the radiative balance, the distribution of precipitation, and the chemistry of the Earth's atmosphere. Measurements of the water vapor mixing ratio paired with stable isotope ratios provide unique information on transport processes and moisture sources that is not available with mixing ratio data alone. Measurements…
Hydrogen isotope ratios of lacustrine sedimentary n-alkanes as proxies of tropical African hydrology: Insights from a calibration transect across Cameroon
Hydrogen isotope values (δD) of sedimentary aquatic and terrestrial lipid biomarkers, originating from algae, bacteria, and leaf wax, have been used to record isotopic properties of ancient source water (i.e., precipitation and/or lake water) in several mid- and high-latitude lacustrine environments. In the tropics, however, where both processes associated with…
Origins of Groundwater Inferred from Isotopic Patterns of the Badain Jaran Desert, Northwestern China
There are many viewpoints about the sources of groundwater in the Badain Jaran Desert (BJD), such as precipitation and snowmelt from the Qilian Mountains (the upper reaches [UR] of the Heihe River Basin [HRB]) and precipitation from the BJD and the Yabulai Mountains. To understand the source of the groundwater of the BJD and their…
Lakewater paleothermometry from Deep Lake, Minnesota during the deglacial–Holocene transition from combined δ18O analyses of authigenic carbonate and aquatic cellulose
Carbonate, cellulose, and bulk organic isotope data from varved sediments of Deep Lake (Minnesota) provide a record of paleohydrologic and paleoclimatic change during the deglacial–Holocene transition from 12,000 to 7500 cal BP. Deep Lake became enriched in 18O in response to increased influence of maritime tropical moisture from the Gulf of Mexico…
Quantifying instantaneous regeneration rates of plant leaf waxes using stable hydrogen isotope labeling
Leaf waxes protect terrestrial plants from biotic and abiotic stresses and are important sedimentary biomarkers for terrestrial plants. Thus, understanding the production and ablation of leaf waxes is critical in plant physiology and for geochemical studies. However, there have been no accurate approaches to quantify leaf wax production at different time scales. In this study, we…
Reducing and correcting for contamination of ecosystem water stable isotopes measured by isotope ratio infrared spectroscopy
oncern exists about the suitability of laser spectroscopic instruments for the measurement of the (18)O/(16)O and (2)H/(1)H values of liquid samples other than pure water. It is possible to derive erroneous isotope values due to optical interference by certain organic compounds, including some commonly present in ecosystem-derived samples such as leaf or soil waters. Here we…
ISO-CADICA: Isotopic – continuous, automated dissolved inorganic carbon analyzer
RATIONALE
Quantifying the processes that control dissolved inorganic carbon (DIC) dynamics in aquatic systems is essential for progress in ecosystem carbon budgeting. The development of a methodology that allows high-resolution temporal data collection over prolonged periods is essential and is described in this study.…
Continuous analysis of δ18O and δD values of water by diffusion sampling cavity ring-down spectrometry: a novel sampling device for unattended field monitoring of precipitation, ground and surface waters
A novel sampling device suitable for continuous, unattended field monitoring of rapid isotopic changes in environmental waters is described. The device utilises diffusion through porous PTFE tubing to deliver water vapour continuously from a liquid water source for analysis of δ18O and δD values by Cavity Ring-Down Spectrometry (CRDS). Separation of the…
Greenhouse Gas and Ozone Measurements from Aircraft in Alaska 2009 - 2011
Presentation Description:
The NOAA ESRL GMD Carbon Cycle and Greenhouse Gases Group’s aircraft network consists of 18 sites, mostly in North America, that conduct bi-weekly flask sampling over given locations to altitudes of 8000 m above sea level (masl). Most sites sample 12 flasks during an altitude profile, and through collaboration with GMD’s Ozone group, many…
Continuous in situ measurements of stable isotopes in liquid water
We developed a method to measure in situ the isotopic composition of liquid water with minimal supervision and, most important, with a temporal resolution of less than a minute. For this purpose a microporous hydrophobic membrane contactor (Membrana) was combined with an isotope laser spectrometer (Picarro). The contactor, originally…
Real-time monitoring of breath ammonia during haemodialysis: use of ion mobility spectrometry (IMS) and cavity ring-down spectroscopy (CRDS) techniques
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…
Spatially telescoping measurements for improved characterization of ground water-surface water interactions
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…
Macropore flow of old water revisited: where does the mixing occur at the hillslope scale?
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…
Isotopic values of the Amazon headwaters in Peru: comparison of the wet upper Río Madre de Dios watershed with the dry Urubamba‐Apurimac river system
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.
METHODS:
Different kind of water (spring,…
A 1-year long δ18O record of water vapor in Niamey (Niger) reveals insightful atmospheric processes at different timescales
We present a 1-year long representative δ18O record of water vapor (δ18Ov) in Niamey (Niger) using the Wavelength Scanned-Cavity Ring Down Spectroscopy (WS-CRDS). We explore how local and regional atmospheric processes influence δ18Ov variability from seasonal to diurnal scale. At seasonal scale, δ18O…
Assessing the Rate and Timing of Leaf Wax Regeneration in Fraxinus Americana Using Stable Hydrogen Isotope Labeling
RATIONALE
Understanding leaf wax regeneration and recycling is crucial for plant physiology and paleoclimate studies. However, our recent isotope labeling experiments on a grass species (Phleum pratense) yielded different conclusions from published data on a tree species (Populus trichocarpa), with the…
Geochemistry of a continental saline aquifer for CO2 sequestration: The Guantao formation in the Bohai Bay Basin, North China
The Neogene Guantao formation in the Beitang sag in the Bohai Bay Basin (BBB) of North China, a Mesozoic–Cenozoic sedimentary basin of continental origin, has been chosen as a candidate for a pilot field test of CO2 sequestration. Hydrogeological and geochemical investigations have been carried out to assess its suitability, taking advantage of many existing geothermal wells…
Measuring variations of δ18O and δ2H in atmospheric water vapour using laser spectroscopy: an instrument characterisation study
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…
Process-evaluation of tropospheric humidity simulated by general circulation models using water vapor isotopologues: 1. Comparison between models and observations
The goal of this study is to determine how H2O and HDO measurements in water vapor can be used to detect and diagnose biases in the representation of processes controlling tropospheric humidity in atmospheric general circulation models (GCMs). We analyze a large number of isotopic data sets (four satellite, sixteen ground-based remote…