Photosynthesis is a complex process that consumes carbon dioxide and water to produce oxygen and glucose. Studies to investigate leaf-level photosynthetic activity have been conducted using systems that control certain parameters such as light intensity or partial pressure of CO2. For instance, the LI-COR LI‑6800 Portable Photosynthesis System enables the user to control and measure light,…

•  The air quality inside vehicles is affected by the intake of polluted air and by outgassing of fabrics.
•  Airlabs developed a portable air cleaner, the airbubbl, to remove particulate matter, NO2 and other pollutants from air. A new filter was designed to also remove formaldehyde.
•  Here, we present the performance of the new formaldehyde filter, also in…

Atmospheric concentrations of N₂O, CO₂and CH₄ are currently steadily increasing, and in the case of N₂O, the increase in emissions is mainly linked to the increased use of fertilizers in agricultural soils. Stable isotope analysis of these trace gases is a valuable tool to better understand production and consumption pathways in soils and this…

Differentiating microbial, anthropogenic, and thermogenic sources of carbon dioxide (CO₂) and methane (CH₄) in background air is an important element of understanding
upper ocean ecosystem processes. Here we present isotopic data of carbon dioxide and methane from the Fleur de Passion sailing research vessel which traveled from Dakar (Senegal) to Carbo Verde, the…

Oxygen (¹⁸O/¹⁶O) and deuterium (D/H) isotopes are a widespread tool to trace physical and chemical processes in hydrology and biogeosciences. Precision and throughput are key parameters for water isotope analysis. Here, we will present two new methodologies for the Picarro L2130-i Cavity Ring-Down Spectroscopy (CRDS) water isotope analyzer that allow the user…

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Atmospheric oxidation is dominated by the OH radical, although Cl atoms can play an important role under certain conditions. Gas-phase inorganic chlorine (Cl_y) controls the Cl budget. HCl dominates Cl_y[1]. Atmospheric sources and levels of HCl are poorly constrained. HCl is a sticky gas and is a challenge to measure with high time resolution. Most…

Methane Soil Flux Estimates Using Mobile and High Precision Cavity Ring Down Spectroscopy

In the dynamic landscape of gas leak investigations, mastering the intricacies of Picarro Leak Indications (LISAs) is crucial for efficient and accurate detection. In this training video, we delve into the unique investigative process required for Picarro indications, setting it apart from traditional leak surveys.

The Caddy Continuous Flow Interface has previously been used to connect available solid and
liquid bulk sample preparation instruments—including the Picarro Combustion Module—to
Picarro analyzers for high-precision carbon isotope (¹³C) measurements.

Picarro is happy to announce the AutoMate Prep Device from AutoMate FX as the Caddy’s
newest pairing. The Caddy’s…

Atmospheric carbon dioxide (CO₂) mole fractions were continuously measured from January 2009 to December 2011 at four atmospheric observatories in China using cavity ring-down spectroscopy instruments. The stations are Lin'an (LAN), Longfengshan (LFS), Shangdianzi (SDZ), and Waliguan (WLG), which are regional (LAN, LFS, SDZ) or global (WLG) measurement stations of the World…

Measurements of the ¹⁷O_excess of H₂O were obtained from ice cores in West and East Antarctica. Combined with previously-published results from East Antarctica, the new data provide the most complete spatial and temporal view of Antarctic ¹⁷O_excess to date. There is a steep spatial gradient of ¹⁷O_excess in present-…

Facilitation and competition between different vegetation layers may have a large impact on small-scale vegetation development. We propose that this should not only influence overall herbaceous layer yield but also species distribution and understory longevity, and hence the ecosystems carbon uptake capacity especially during spring. We analyzed the effects of trees on…

We report trends in springtime ozone (O₃) and carbon monoxide (CO) at the Mt. Bachelor Observatory (MBO) in central Oregon, U.S.A. from 2004 to 2013. Over the 10-year period the median and 95th percentile springtime O₃ increased by 0.76 ± 0.61 ppbv yr⁻¹ (1.7 ± 1.4% yr⁻¹) and 0.87 ± 0.73 ppbv…

Biogeochemical dynamics under seasonal ice cover were investigated in the shallow (<10 m) water column of highly productive Georgetown Lake, western Montana, USA. This high altitude (1,800 m) reservoir is well-mixed in summer, but becomes strongly stratified under ice cover (mid-November–mid-May). A rapid drop in dissolved oxygen (DO) concentration and rise in dissolved…

Stable isotopes in water (δ²H and δ¹⁸O) are important indicators of hydrological and ecological pattern and process. δ²H and δ¹⁸O of water are incorporated into geological and biological systems in a predictable manner and have been used extensively as tracers in hydrological, ecological and forensic studies. Physical processes result in spatial…

An instrumented sample holder was developed for time-lapse micro-tomography of snow samples to enable in-situ nondestructive spatial and temporal measurements under controlled advective airflows, temperature gradients, and air humidities. The design was aided by computational fluid dynamics simulations to evaluate the airflow uniformity across the snow sample. Morphological and mass…

In the Ziz Basin, located in arid area in southeastern Morocco, surface waters are scarce and local populations are entirely dependent on groundwater resources for drinking and irrigation. In order to evaluate the main factors controlling the origin and salinization of groundwater resources, we have investigated the chemical and stable isotope compositions of groundwater and surface water…

The chemical and physical properties of secondary organic aerosol (SOA) formed by the photochemical degradation of biogenic and anthropogenic volatile organic compounds (VOC) are as yet still poorly constrained. The evolution of the complex refractive index (RI) of SOA, formed from purely biogenic VOC and mixtures of biogenic and anthropogenic VOC, was studied over a diurnal cycle in the…

• The oxygen isotope signature of water is a powerful tracer of water movement from plants to the global scale. However, little is known about the short-term variability of oxygen isotopes leaving the ecosystem via transpiration, as high-frequency measurements are lacking.
• A laser spectrometer was coupled to a gas-exchange chamber directly estimating branch-level fluxes in order…

In order to better understand the constraints on the use of barium as a coastal paleo-freshwater tracer, we surveyed the dissolved Ba distribution in Louisiana Shelf waters, including the Mississippi (MR) and Atchafalaya (AR) River plumes, during May and November 2008, and June/July 2009, which represent high, low and intermediate river discharges, respectively. Dissolved Ba was found…

In atmospheric and environmental sciences, optical spectrometers are used for the measurements of greenhouse gas mole fractions and the isotopic composition of water vapor or greenhouse gases. The large sample cell volumes (tens of milliliters to several liters) in commercially available spectrometers constrain the usefulness of such instruments for applications that are limited in sample…

In this paper, we report the vertical profiles of CO₂ and CH₄ measured with a cavity ring-down spectrometer (CRDS) on a research aircraft from near-ground level to 8 km above mean sea level. The airborne platform employed in this paper is an Alpha Jet aircraft operated from NASA's Ames Research Center. Flights were undertaken to Railroad Valley, NV, USA, to…

Hillslopes are the dominant landscape components where incoming precipitation is transferred to become groundwater, streamflow or atmospheric water vapor. However, directly observing flux partitioning in the soil is almost impossible. Hydrological hills-lope models are therefore being used to investigate the involved processes. Here we report on a modeling experiment using the Catchment…

Precise methods for the detection of geologically stored CO₂ within and above soil surfaces are an important component of the development of carbon capture and storage (CCS) under terrestrial environments. Although CO₂ leaks are not expected in well-chosen and operated storage sites, monitoring is required by legislation and any leakage needs to be quantified…

A Particle-into-Liquid Sampler – Total Organic Carbon and fraction collector sys-tem was flown aboard a Twin Otter aircraft sampling prescribed burning emis-sions in South Carolina in November 2011 to obtain smoke marker measure-ments. The fraction collector provided 2min time-integrated off-line samples for car-bohydrate (i.e., smoke markers levoglucosan, mannosan, galactosan) analysis by…

Emissions of methane (CH₄) from oil and natural gas (O&G) operations in the most densely drilled area of the Denver-Julesburg Basin in Weld County located in northeastern Colorado are estimated for 2 days in May 2012 using aircraft-based CH₄ observations and planetary boundary layer height and ground-based wind profile measurements. Total top-down CH_4…

Water is the key resource limiting world agricultural production. Although an impressive number of research reports have been published on plant drought tolerance enhancement via genetic modifications during the last few years, progress has been slower than expected. We suggest a feasible alternative strategy by application of rhizospheric bacteria coevolved with plant roots in harsh…

Silage is an important dietary water source that influences the oxygen and hydrogen isotopic composition of domestic herbivores and their products. Silage sampled fresh from the silo had¹⁸O- and ²H-depleted tissue water when compared with fresh pasture grass sampled around midday during the silage-making seasons. During exposure in the feed bunk, silage water…

Degradation of plant material by animals is an important transformation pathway in the nitrogen (N) cycle. During the involved processes, volatile reduced alkaline nitro-gen compounds, mainly ammonia (NH₃) and aliphatic amines such as trimethylamine (TMA), are formed. Today, animal husbandry is estimated to constitute a main source of aliphatic amines into the atmosphere with TMA…

Hydrological and geochemical processes controlling the pore water chemistry in a permafrost wetland, with loam overlain by sphagnum peat, were investigated. The vertical distributions of dissolved Cl, and of pore water δ¹⁸O, appeared unrelated to ion freeze-out and isotope ice-water fractionation processes, respectively, dismissing solute freeze-out as a main control on the water…

Hydrogeochemistry of 32 hot springs in the western Sichuan Province after the Wenchuan  8.0 earthquake was investigated by analyzing the concentrations of cation and anion and the isotopic compositions of hydrogen and oxygen. The water samples of the hot springs were collected four times from June 2008 to April 2010. Hydrogeochemical data indicated the water samples can be…

The East Scotia Ridge is an active back-arc spreading centre located to the west of the South Sandwich island arc in the Southern Ocean. Initial exploration of the ridge by deep-tow surveys provided the first evidence for hydrothermal activity in a back-arc setting outside of the western Pacific, and we returned in 2010 with a remotely operated vehicle to precisely locate and sample…