The Nitrogen Inventory of the Yedoma Permafrost Region

• Main Authors: Strauss, Jens, Beermann, Fabian, Biasi, Christina, Fiencke, Claudia, Grosse, Guido, Kutzbach, Lars, Sanders, Tina, Schirrmeister, Lutz, Schneider von Deimling, Thomas, Wetterich, Sebastian, Zubrzycki, Sebastian
• Format: Conference Object
• Language: unknown
• Published: 2016
• Subjects: Climate change; Global warming; Ice; permafrost; Tundra; wedge*; Alaska; Siberia
• Online Access: https://epic.awi.de/id/eprint/41173/; https://hdl.handle.net/10013/epic.48123

The biogeochemical composition of fossil organic matter stored in permafrost is an important subject in current climate change research. Multiple studies on the quality and quantity of permafrost organic carbon suggest that there is a high potential for carbon release into the active carbon turnover cycle through permafrost thaw in a warming Arctic. Other components of organic matter that are important for biogeochemical cycling, however, are less studied so far, including the amount and distribution of nitrogen (Keuper et al., 2012; Mack et al., 2004; Rustad et al., 2001). Nitrogen from thawing permafrost could be a significant source of the greenhouse gas N2O. Given its high global warming potential (about 300 times larger than CO2 over 100 years), even small releases of N2O can affect the permafrost-climate feedback. This study focuses on the abundance and distribution of nitrogen currently freeze-locked in the Yedoma region of Siberia and Alaska. Organic matter in permafrost deposits of the northern circumpolar region accumulated over tens of thousands of years during the last glacial and interglacial periods. A part of this permafrost region, the Yedoma region, is composed of thick ice-rich silts intersected by large ice wedges, resulting from sedimentation and syngenetic freezing accompanied by ice wedge growth in polygonal tundra, which was driven by certain climatic and environmental conditions during the late Pleistocene. These unique materials are called Yedoma deposits. They constitute a large organic carbon inventory of the (sub)Arctic but are also known to be nutrient-rich due to burial and freezing of plant remains. Besides carbon inventory estimates, detailed quantification of total nitrogen (TN) stocks is lacking. Based on the most comprehensive data set of TN content in permafrost to date, our study aims to estimate the present pool of nitrogen stored in the different stratigraphic units of the Yedoma region, which are (1) late Pleistocene Yedoma deposits; (2) in-situ thawed and diagenetically ...