Real-time chemical mapping of a river using OA-ICOS Technology
Real-time chemical mapping of a river using OA-ICOS Technology

Real-time chemical mapping of a river using OA-ICOS Technology

The carbon cycling and conversion to CO2 or CH4 follows specific dynamics in coastal ecosystems that combine water and sediments. In order to better understand this accelerated cycle, a group of marine scientists from Whoods Hole Oceanographic Institution (USA) have developed the gas-powered autonomous surface vehicle (ASV) “ChemYak” equipped with various in-situ sensors for water composition analysis and meteorologic measurements.


The ASV allows to perform carbon cycle mapping in the coastal zone with high spatial and temporal resolution, and accurately follow preplanned routes even in remote locations, with precise speed control.

The ASV was fitted with LGR’s membrane-based Dissolved Gas Extraction System (DGES) coupled with an Ultraportable Greenhouse Gas Analyzer (U-GGA-915) to perform real-time measurements of dissolved CO2 and CH4 in coastal waters. The LGR instrumentation was preferred over other commercial sensors for dissolved methane analysis, thanks to its superior accuracy and response time.

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Dissolved Gas Extraction System (left) and Ultraportable Greenhouse Gas Analyzer (right)

In attached article “Rapid Mapping of Dissolved Methane and Carbon Dioxide in Coastal Ecosystems Using the ChemYak Autonomous Surface Vehicle”, the marine scientists describe an application example of the complete measurement system for coastal water composition mapping in the North River estuary, 30 miles south of Boston (MA, USA). The ASV was deployed in both the main estuary channel and the smaller Cove Brook tidal creek during a 1-day field test.

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ChemYak ASV equipped with various chemical and weather sensors (Nicholson et al.)

The paper provides a detailed and thorough illustration of the combined efficiency of the DGES coupled to U-GGA-915 for in-situ analysis of dissolved gases. In particular, it describes precisely the procedure to characterize the gas extraction efficiency of the DGES.

Data generated with the DGES + U-GGA-915 showed that dissolved CH4 and CO2 values increased upriver, reflecting a net flux to the atmosphere from the North River estuary. Authors also observed that levels of CHand CO2 in the 1-km Cove Brook section were significantly higher than in the main North River channel.


Mapping of partial CO2 and CH4 pressure through North River main estuary and Cove Brook tidal creek (Nicholson et al.)

They also demonstrated that the relationship between salinity and water chemistry was clearly distinct between the main channel and side channel, indicating a distinct freshwater end-member, influenced by an additional source of CO2 and CH4.

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Dissolved CO2 and CH4 concentratrion in main channel and Cove Brook side channel of North River as a function of salinity (Nicholson et al.)

This work represents the first use of an ASV utilized for dissolved CH4 measurements. The authors concluded that the various sensors aboard the ChemYak allowed to collect high-quality continuous data, providing orders of magnitude more data than if characterization had been conducted by water sample collection. In addition, all chemical analysis was done in situ and not in the laboratory, greatly expediting generation of deployment results. This ASV-base approach opens up future opportunities for adaptive sampling using real-time sensor feedback and coordinated, multivehicle operations.



The stable isotopic compositions of rainfalls is affected by complex meteorological and geographical factors, such as atmospheric conditions at the moisture source and precipitation site, moisture transport trajectories, altitude of condensation and latitude. Therefore, stable isotopes of water (2H, 18O and more recently 17O) can be used as natural tracers in ecohydrological and meteorological research, providing information on precipitation formation and transport mechanisms.

In the attached report “Stable isotope variations of daily precipitation from 2014–2018 in the central United States“, hydrogeologists from Indiana University-Purdue University Indianapolis (IUPUI) presented a four-year daily precipitation isotope dataset collected at mid-latitudes (Zionsville, Indiana, USA) and measured with LGR Water Vapor Isotope Standard Source (WVISS) and Triple Water Vapor Isotope Analyzer (TWVIA-912).

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Water Vapor Isotope Standard Source (WVISS) and Triple Water Vapor Isotope Analyzer (TWVIA-912)

The influencing factors of the precipitation formation at the study site are complex and caused by different water vapor sources (Continental, Pacific, Atlantic, Gulf of Mexico, and Arctic). The procedure for sampling, measuring, calibrating and post-processing the data is detailed in the report. Multiple standards were used to validate the measurements and the precision values were compared with reported values in the literature.


δ2H, δ18O, δ17O, d-excess and 17O-excess values of daily precipitation from

June 2014 to May 2018 in Indianapolis, Indiana, U.S. (Tian & Wang)

The authors concluded that the precisions of the three individual isotopes (δ2H, δ18O and δ17O) was in line with finding from previous studies. In addition, they observed that the precision of  17O-excess –which is a relatively new tracer- is comparable with Isotopic Ratio Mass Spectrometry (IRMS) which has long been considered as the reference method for isotopic analysis. The dataset is made it available to researchers around the world who may use it as a reference for site comparisons and for assessing global hydrological models.

Additional information on the research efforts of that group at IUPUI is provided in that educational video from Professor Wang, that features the LGR TWVIA-912 analyzer in action:


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Monitoring low levels of formaldehyde in ambient air News: Monitoring low levels of formaldehyde in ambient air

Formaldehyde, chemical formula HCHO or CH2O, is a colorless gas with a pungent odor. Levels above 0.1 ppm can cause allergy and acute health problems, e.g. sore throat, skin irritation, nausea, scratchy eyes and cough. Formaldehyde (HCHO) is also classified as highly carcinogenic compound. Exposure to moderate amounts of HCHO has been linked to cancer, such as leukemia.

New carbon dioxide isotope analyzers News: New carbon dioxide isotope analyzers

Stable isotopes act as tracers for studying flows and fluxes of material through ecosystems and the atmosphere. In practice, scientists measure the stable carbon isotope content of air, plants and soil to quantify many phenomena including the recycling of carbon dioxide within forests, water use efficiency, partitioning ecosystem carbon exchange into its components, gross primary productivity and ecosystem respiration, and to identify and quantify the distribution and contributions of plant species to global productivity. In addition, stable isotopes of carbon may be used to determine the effectiveness of carbon sequestration strategies. For these studies, investigators require fast, accurate measurements over a wide range of carbon dioxide concentrations.

ABB LGR-ICOS Carbon Dioxide Isotope analyzers exceed all of these requirements.

Cloud Condensation Nuclei (CCN) counter News: Cloud Condensation Nuclei (CCN) counter

Droplet's CCN-100/200 measures the count and size of individual aerosol particles that can form into cloud droplets. Its fast response time allows use in either airborne or ground-based stations.

Photoacoustic detector for solid, semi-solid and liquid samples News: Photoacoustic detector for solid, semi-solid and liquid samples

The INRAe of Narbonne has bought an ultra-high performance photoacoustic detector for solid, semi-solid and liquid samples (a PA301 module produced by Gasera). The PA301 is used as an accessory for any FTIR device. Last week, the Envicontrol team provided on site setup and a full training has been given.

Flux measurements News: Flux measurements

Los Gatos Research (LGR) now offers more analyzer choices to measure surface-atmosphere fluxes. Traditionally, there are four main flux measurement techniques: Eddy Covariance, Relaxed Eddy Accumulation, Gradient and Chamber-based. Though carbon dioxide and water vapor are the most common greenhouse gases measured, in many ecosystems a number of different gases must be measured. LGR's technology has improved rapidly over the years and new analyzers are now available allowing scientists to expand their research by measuring other greenhouse gases such as methane, nitrous oxide, carbon monoxide, ammonia, and carbonyl sulfide.

Envicontrol Germany News: Envicontrol Germany

Envicontrol is increasing his presence in Europe with the setup of a subsidiary in Germany. Envicontrol GmbH is now fully established in Köln.

From Germany, for any commercial request, please contact Hans Helsen. For technical support, contact Tobias Könemann.

We are close to our customers and will be even closer tomorrow.

VMM choose our NOx analyzers News: VMM choose our NOx analyzers

The Vlaams Milieu Maatschappij (VMM) has chosen to work with Envicontrol for the NOx monitoring within the Flemish air quality monitoring network. The T200 analysers from TAPI will take place soon and 45 units are foreseen to be delivered before the end of 2021.

Measuring ships SO2 emissions with OPSIS News: Measuring ships SO2 emissions with OPSIS

Last week during the ship's stopover at the harbour of Antwerp, the Envicontrol team has maintained the OPSIS analyser monitoring CO2 and SO2 on the “Nabucco” vessel.

We participate in various fairs and seminars around Europe where we can keep you informed of the latest developments and possibilities in the field of measurement and analysis equipment. Below you will find an overview of the events we visited recently and the events where you can meet us soon.


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