MEMO2: MEthane goes MObile – MEsurements and MOdelling

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Mila Stanisavljevic – Adventurous month in Germany

Just after the holidays and 2019 New Year eve, my secondment started in Germany at the Institute of Environmental Physics, Heidelberg University (UHEI). I have spent one fruitful month working together with ESR1 Piotr Korben at Dr. Martina Schmidt’s group. Before I collaborate with colleague Piotr (and part of his team) in terms of the CoMet campaign, so it was not a big deal to work again with a great colleague.

The goal of secondment was: to learn more about instrument capability (Picarro CRDS and Los Gatos Research ICOS off-axis instruments (LGR)), work with AirCore system (Hoheise et al., 2019, Rella et. al, 2015), and organize measurement campaigns.

So, let us start: the first 2 weeks was booked for testing of the instrument in laboratory conditions and testing them in-field measurement around Heidelberg city region. We performed a lot of new experiments, e.g. Influence water vapor on our measured methane concentrations (in laboratory conditions). Figure 1 illustrates all necessary equipment: cooling trap, analyzer and protecting glasses. Later on I was able to run all experiments in the host laboratory at AGH.

Figure 1: Laboratory equipment: Colling trap – left, Picarro G2201-i CRDS analyser- middle; protecting glasses- right

During the secondments, we did not spend time only in laboratory. We conducted mobile measurements on our untypically way: biking around Heidelberg city. The capability of the lightweight instrument allows as to organize biking tour with LGR on board (Figure 2). That kind of analyser allows as to pass roads which we are not capable to do with car. In one day we made biking tour with 30km – uhh good for science and for a health.

Figure 2: Left: LGR analyser in laboratory conditions; Right: bike ready for new adventure

Methane, methane, methane … Colleague Piotr help me to learn how to use their AirCore system (Figure 3). In principle AirCore system is a long tube connected to Picarro analyser, capable to store air. Stored air is measured again in order to obtain more measurements points. Beside methane, AirCore tool help us with measurements of δ13CH4. Theoretically more measurements points of δ13CHmeans more precise results. By this technique we can replace ‘old fashion’ bag samples storage. After identification of methane concertation (plume) and trepid gas onto tube, system allows methane peak analysis – in situ, just after 2 min of identification… Hence analysis and information are going quickly.

Figure 3: Air core system: left tube connected to the Picarro CRDS analyser, right schematic of the system. Figure is modified from Hoheise et al. 2019

To collect more data for future PhD we organize measuring campaign around hard coal mining area in Germany. The interesting thing about Germany is that all hard coal facility stopped with work and excavation of coal, but we were curious to see does mine shafts still emits methane. And we were right… Even if last shaft was closed December 2018 we were able to identified methane concertation above background.

Figure 4: Measurement system: left: Picarro analyser installed into van together with AirCore system, right upper photo, 2D wind measurements; right lower photo typical Picarro record in the surrounding of coal mines

At the end all knowledge obtained during one month, give me opportunity to collaborate more closely with colleagues from UHEI, bring knowledge to build new small devices in host laboratory and escape from clod Polish winter this year. As it is always case, beside learning new skills about measurements, methane, we had a time to learn about historical Heidelberg city and enjoy in a taste cakes.

Figure 5: Free time during secondments: taste cake and beautiful city of Heidelberg

Reference:

  1. Hoheisel, Antje, et al. “An improved method for mobile characterisation of δ13CH4 source signatures and its application in Germany.” Atmospheric Measurement Techniques, vol. 12, no. 2, 22 Feb. 2019, pp. 1123–1139.
  2. Rella, C.W., Tsai, T.R., Botkin, C.G., Crosson, E.R. and Steele, D. (2015). Measuring emissions from oil and natural gas well pads using the mobile flux plane technique. Environmental Science & Technology, 49(7), pp.4742–474