Quantitech supports Arctic greenhouse gas research

A scientist from the University of Saskatchewan in Canada has successfully used a Quantitech Gasmet DX4015 FTIR analyser to monitor gases in the High Arctic of Canada.

Martin Brummell employed the DX4015 on his most recent research expedition to investigate the soils in the polar deserts of the High Arctic. Carried out on Ellesmere Island in the Baffin Region of Nunavut, Canada, the device had to perform reliably in extreme environmental conditions. The analyser was used to monitor the production, consumption and atmospheric exchange of the greenhouse gases Carbon Dioxide (CO₂), Methane (CH₄) and Nitrous Oxide (N₂O). These gases are released and up-taken by soil microbes in the Arctic.

The DX4015 was used to examine both the flux of gases from the soil surface and the concentration profiles of gases in the soil’s active layer above the permafrost. In doing so the FTIR provides raw data consisting of gas concentrations in parts-per-million (ppm).

Brummell drove a set of simple, perforated steel tubes into the soil, to the point of the permafrost threshold. Inside these tubes gases within the soil were allowed to reach equilibrium via diffusion over 24 hours. This allowed Brummell to analyse gas concentrations to a depth of one metre. The procedure was simple and repeatable. Furthermore, measurement of gas concentrations at different depths enabled direct comparison with soil analysis.

‘The real-time nature of the Gasmet FTIR, allows me to see results within minutes of setting up in the field,’ said Brummell. ‘This permits me to make changes to the experimental design and further investigate unexpected results whilst in the field. This contrasts with traditional methods of soil gas analysis, which employ lab-based gas chromatography systems and collection of samples ‘blind’ in the field.’

The work revealed areas of strong CO₂ and CH₄ production immediately above the permafrost, which Brummell believes is the result of the relative disparity in carbon distribution in Arctic soils compared with warmer climates. Carbon accumulates far lower in Arctic soils due to cryoturbation, which is the constant mixing and burying of organic matter, which fuels microbial activity at a deeper level.

Comparisons between the surface flux and the soil profile for each of the greenhouse gases was a key objective within Brummell’s investigation. Most notably, he observed a negative surface flux for NO₂, but no significant regions of consumption were identified. The location of the NO₂ sink is not yet clear, nor the organisms and biogeochemical processes responsible.

Brummell’s research also highlighted the importance of reliability, ruggedness, flexibility and accuracy in the equipment employed in such work. The DX4015’s ability to provide simultaneous measurement of multiple gases in near real-time was a major advantage.

‘In contrast to other field equipment I have used in the High Arctic, including self-destructing sledgehammers, unreliable generators and broken fibre-optic cables, the Gasmet DX4015 has never failed even in the most difficult field conditions. It has happily survived air-transport, inconsistent electrical supply, low temperatures, rain, snow, mud and all other insults, and always gives me accurate, precise measurements of gas concentrations,’ he said.

The Gasmet DX4015 is a portable FTIR (fourier-transform infrared) gas analyser for ambient air analysis. It is able simultaneously to analyse up to 50 gas compounds.

The device is operated using a laptop computer running Calcmet software, which is capable of simultaneous detection, identification and quantification of ambient gases. It can be used in a number of applications, including industrial emissions monitoring, occupational safety surveys, engine exhaust testing, process monitoring, leak detection, emergency response, chemical spill and fire investigations.