April 6, 2010

Results based on permafrost cores collected as part of the IPY UNIS course AG-333 are now published in Nature Geoscience

Contact person for additional information: Hanne H Christiansen

Text and photos by  Hanne H. Christiansen.

 

High nitrous oxide production from thawing permafrost is the title of a Nature Geoscience paper authored by two UNIS-professors Bo Elberling and Hanne H. Christiansen, and published online today. Here, surprisingly high nitrous oxide production rates based on incubated permafrost samples are reported. The scientific results is based on successful externally funded multidisciplinary permafrost IPY research approach coordinated by the UNIS Arctic Geology Department, combining teaching and research across the large climatic gradient between Greenland and Svalbard with permafrost samples collected by UNIS students in Svalbard as well as in Zackenberg (High Arctic NE Greenland). This was done in the master & ph.d. level AG-333 The International University Course on High Arctic Permafrost Landscape Dynamics in Svalbard and Greenland . This course was run as a special IPY course sponsored jointly by the Arctic Geology Department at UNIS, the Thermal State of Permafrost in Norway and Svalbard (TSP NORWAY) IPY research project, the Norden Arctic Co-operation Programme 2006-2008 and the Zackenberg Research Station.

Paper summary: Permafrost soils contain nearly twice as much carbon as the atmosphere. When these soils thaw, large quantities of carbon are lost, mainly in the form of methane and carbon dioxide. In contrast, thawing is thought to have little impact on nitrous oxide emissions, which remain minimal following the summer thaw. Here, we examined the impact of thawing on nitrous oxide production in permafrost soils collected from a heath and wetland site in Zackenberg, Greenland . Rates of nitrous oxide production in the heath soil were minimal, regardless of the hydrological conditions. Although rates of nitrous oxide production in the wetland soil were low following thawing, averaging 1.37 g N day-1 kg-1, they were 18 g N day-1 kg-1 in permafrost cores following thawing, drainage and rewetting with the original meltwater. We show that 31% of the nitrous oxide produced after artificial 10 cm thawing and rewetting equivalent to 34 mgN m-2 d-1 was released to the atmosphere; this is equivalent to the daily nitrous oxide emissions from tropical forests on a mean annual basis. Measurements of nitrous oxide production in permafrost samples from five additional wetland sites in the high Arctic, including from Svalbard, suggest that the rates of nitrous oxide production observed in the Zackenberg soils may be in the low range, whereas the Svalbard ones are higher.

Permafrost coring in Zackenberg, NE Greenland, August 2008. Photo: Hanne H. Christiansen.

 

The AG-333 student group and its two lecturers at the summit of the mountain Aucellaberget in Zackenberg, August 2008. Photo: Bo Elberling.

 

Special thanks to the ten UNIS course AG-333 students for their hard work in obtaining the permafrost cores studied, and to AG-333 student Louise Berg for laboratory assistance.

Correspondence and requests for materials should be addressed to Professor Bo Elberling, Department of Geography and Geology, University of Copenhagen , ster Voldgade 10, DK-1350 Copenhagen, Denmark; E-mail: be@geo.ku.dk