The main aim of the field sampling in April was to put up a series of ‘frisbee’ traps to collect dust in the lake catchments across the Kangerlussuaq area from the ice sheet to the mid-fjord area. This required hiking to most sites and occasionally wading through knee deep snowdrifts, given the unusual amounts of snow this year. Great effort by the dust team Maud, Matt, Jo and John for struggling through all of this. The frisbees are now installed doing their thing and will be joined by a two continuous monitoring dust track stations to be put up in the summer.
Meanwhile, we also collected snow samples from the lake surfaces to look at the dust which had collected there over the winter. This was a bit of an unknown, because we did not know how ‘dirty’ the snow would be. So the first samplings involved digging large snow pits and backpacking the snow from the lakes. Again, not easy in deep snow. We also collected lake water samples by boring through the lake ice.
Back at the lab, the snow was melted and filtered, revealing much higher dust quantities that we expected, and meaning that it was probably not necessary to collect so much snow. A useful pilot study. The rest of the time was spent analysing the chemistry of the snow and lake waters, and packing up samples for analysis back in the UK.
Loughborough PhD Student Maud Van-Souest who will be looking at dust-soil interactions in Kangerlussuaq gives us her first impressions:
It has been a week ago already since I made my first steps on the Greenlandic soil. John Anderson, Joanna Bullard, Matthew Baddock and I took the plane from Copenhagen to Kangerlussuaq on the 20th of April. We have had some magnificent views over the icecap during the flight. One of the first things that John noticed was however that there was way more snow than he expected for this time of the year. That might have cause some problems with the accessibility of the sampling sites. But the sun was working hard and we were about to discover in the following days that it is very normal to wake up and go to bed in a completely different landscape, as sublimation and melting were alternated with periods of fresh snow.
Kangerlussuaq is the main airport of Greenland and not much more than that. The airport is one of the American settlements since the WWII and the small population of about 500 people is almost entirely reliant on the airport and tourist industry. Many scientists stay a few days in Kangerlussuaq to finish the preparations for their fieldwork on the ice or in other remote areas and another few days before they go back home. We are based at KISS (Kangerlussuaq International Science Support) for the full two weeks of this first trip and occupied one of the kitchens and half of the lab space. Especially after we unpacked the pallets and spent some hours in John’s store room (Aladdin’s cave) to install and organise all the equipment.
Ready for the days ahead in the field….
It’s been a busy week since the Dusty project start date on 1 April 2017 (OK perhaps not the best choice of start date…).
We’ve received two ‘Dust trak’ automated monitoring stations which will be used for continuous measurements of dusts along with a weather station. This kit requires some serious battery power to operate in the cold conditions in Greenland.
We also have 30 Hall deposition traps and Fryear dust traps which will be deployed at each lake site to look at local deposition patterns closer to lake sites to be studied in more detail. Added to that are the chemicals we need for analysis and many other smaller pieces of kit that we need for sampling dust and lakes, and you get a massive 8 pallets worth of equipment.
Fortunately, Rebecca McKenzie (pictured left, technician at Loughborough who will be joining the field team in August) and Maud Van Souest (right, PhD student investigating dust in Greenland) were on hand to help with the packing and see off the shipment to Kangerlussuaq, ready for the fieldwork in a few weeks’ time.
A new £700k NERC-funded project due to start in April 2017 will to assess how glacially-derived dust is changing the ecology of Arctic lakes.
The project investigators are from Loughborough University (John Anderson and Jo Bullard), British Geological Survey (Michael Watts) and University of Nottingham (Suzanne McGowan). More information on the project can be found under the Dusty tab.
A new synthesis of the Kangerlussuaq landscape arising from a KAIRN workshop was recently published. The paper focuses on understanding how biogeochemical linkages will change with future warming.
The paper can be accessed here
The NERC-funded Lakes and the Arctic Carbon Cycle (LAC) project draws to a close this month and so the team met in the New Forest to work on finalising the datasets and paper writing. The focus of this meeting was interpreting the Holocene sediment record from Ruppert Lake in Alaska. The extensive suite of proxies analysed on this sediment core includes pollen and plant macrofossils to detect shifts in terrestrial vegetation and remains produced within the lake including geochemical elements, stable isotopes analysed on the organic fraction of sediment, chlorophyll and carotenoid pigments and diatoms. The results arising from the project indicate that terrestrial vegetation shifts have a clear effect on the structure and function of lake ecosystems, indicating that Arctic “greening” has the potential to substantially modify net carbon fluxes between the lake and catchment, with implications of for terrestrial carbon budgets on the landscape scale.
We presented research from the LAC project and from Disko Island at two conferences in Asia this summer. The INQUA conference in Japan (26th July to 2nd August) was held in Nagoya and is held every four years for researchers who study the Quaternary time period (divided into the Pleistocene and Holocene). Suzanne McGowan presented her pigment results from multiple Arctic lakes in northern Norway, Alaska and Greenland, while Pete Langdon presented a poster on the LAC project as well as convening a special session on ‘Tipping points in the late Quaternary’. Mark Stevenson presented his PhD research on Arctic Lakes in Disko Island, west Greenland which included pigment and carbon isotope results. Everyone who attended was in agreement that the INQUA congress was very comprehensive and a great opportunity to networking. Highlighting the importance of this conference to Japan, the emperor and empress of Japan were in attendance at the opening ceremony!
We then made the 3,000km journey (two or three consecutive flights) to Lanzhou in the central interior of China. Here we attended the IPS (International Paleolimnology Symposium) at Lanzhou, China (4th to 7th August). The hospitality offered by the organising committee was very generous and the conference was again a great place to network. We were joined by Maarten van Hardenbroek who gave an excellent presentation on the Alaskan elements of the LAC project and John Anderson who convened a session and spoke enthusiastically on Nitrogen dynamics, which included many references to carbon cycling. The audience were impressed by the detail of the changes that linked to the tree-line advance. Suzanne McGowan in her keynote outlined the importance of ‘ecology’ within palaeo reconstructions, and Mark Stevenson gave his talk on carbon cycling in Disko Island lakes to the west of Greenland. Pete Langdon presented the LAC poster which sparked many hours of discussion and debate and presented an enthusiastic talk on using salmon populations to reconstruct changes in the Atlantic over the past 2,000 years.
We really enjoyed the conferences and are now going into the final stages of the project. As the data rolls in our understanding of the importance of Arctic lakes in the global carbon cycle increases!
Suzanne McGowan at INQUA presenting on carbon cycling using pigments in Arctic lake sediments
Pete Langdon at INQUA presenting the LAC poster
Silhouette of Mark Stevenson at IPS presenting on reconstructing carbon cycling using Dikso Island lake sediments, West Greenland