A summer on Disko:
Methane dynamics in a Greenlandic wetland
by Cecilie Skov
My field season started by the end of May 2014 where I went to Disko off West Greenland with one aim: getting a complete growing season of measurements on the wet snowfence experiment that we established the previous summer. My measurements include methane emissions, dissolved methane, and organic acids in the soil water. Going to Disko, I was very eager to see 1) if the snowfences had worked and accumulated a high pile of snow on the lee side, and 2) how much snow was left (if any). Determining (i.e. guessing) when the growing season will start, and hence when you should be on the site, is a bit of a gamble, so I was eagerly scouting the site from the boat when we passed along the coast. But with snow patches everywhere it was impossible to even point out the snowfences, so the suspense was kept until I could walk to the site the following day.
When I arrived at the site the following day, I was relieved to see that the snowfences had indeed worked. The answer to my second question was also “yes,” there was still snow - a lot of snow. It took two weeks before I could start measuring on the control sides of the fences and three weeks before the snow at the other sides had melted. In the meantime I had plenty of time to measure snow depth, take snow samples, and test my equipment.
Finally, the snow was gone and I could start measuring. I was lucky to have a brand new state of the art ultraportable (20 kg!!) methane analyzer at my disposal, and so I got instant, high-resolution data. In addition, the analyzer made so little noise I could still hear birds singing. Soon, too soon, a master student took over the measurements, so I could go back to Denmark for four weeks and regain some energy for the autumn campaign.
When I came back to Disko early August it was very dry. The area had started to dry out already when I left one month earlier, and the site had received almost no precipitation during that month. The wetland that had been so wet the previous year, when we made the installations, had now gone almost completely dry. I was a bit concerned for my measurements – would I see any treatment effect at all on the methane fluxes when it was so dry? I was almost praying for rain.
Then suddenly came the rain; and lots of it. One Saturday in August it rained so much, that the water supply for the village was out for a few hours, and the Red River rose to almost touch the bridge. The following Saturday it rained again, and this time the river actually washed over the sides of the bridge preventing access to the experimental site.
The rain events presaged the coming of autumn. From then on we had more frequent rain, and by September it turned into snow. It got colder and darker, and it became a struggle to complete a three-day measurement round without interruptions, as we could not measure in heavy rain. But the autumn also meant that the whole valley turned into beautiful colors of yellow and red, rewarding the ones who made the hike out there.
In the end it was time to pack up the stuff and go home. I had fulfilled my goal of covering a complete growing season of measurements despite some struggle with equipment along the way. In addition, I had gotten the arctic seasons under my skin. Experiencing the transformation from early spring to late autumn, and seeing the landscape go through a whole palette of colors, is truly something special. Add to that some whales, the sound of barking sledge dogs, and well, a few mosquitoes, and you have what I consider the essence of Disko Island.