TY - GEN A1 - Fritz, Michael A1 - Opel, Thomas A1 - Tanski, George A1 - Herzschuh, Ulrike A1 - Meyer, Hanno A1 - Eulenburg, A. A1 - Lantuit, Hugues T1 - Dissolved organic carbon (DOC) in Arctic ground ice T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Thermal permafrost degradation and coastal erosion in the Arctic remobilize substantial amounts of organic carbon (OC) and nutrients which have accumulated in late Pleistocene and Holocene unconsolidated deposits. Permafrost vulnerability to thaw subsidence, collapsing coastlines and irreversible landscape change are largely due to the presence of large amounts of massive ground ice such as ice wedges. However, ground ice has not, until now, been considered to be a source of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and other elements which are important for ecosystems and carbon cycling. Here we show, using biogeochemical data from a large number of different ice bodies throughout the Arctic, that ice wedges have the greatest potential for DOC storage, with a maximum of 28.6 mg L-1 (mean: 9.6 mg L-1). Variation in DOC concentration is positively correlated with and explained by the concentrations and relative amounts of typically terrestrial cations such as Mg2+ and K+. DOC sequestration into ground ice was more effective during the late Pleistocene than during the Holocene, which can be explained by rapid sediment and OC accumulation, the prevalence of more easily degradable vegetation and immediate incorporation into permafrost. We assume that pristine snowmelt is able to leach considerable amounts of well-preserved and highly bioavailable DOC as well as other elements from surface sediments, which are rapidly frozen and stored in ground ice, especially in ice wedges, even before further degradation. We found that ice wedges in the Yedoma region represent a significant DOC (45.2 Tg) and DIC (33.6 Tg) pool in permafrost areas and a freshwater reservoir of 4200 km(2). This study underlines the need to discriminate between particulate OC and DOC to assess the availability and vulnerability of the permafrost car-bon pool for ecosystems and climate feedback upon mobilization. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 493 KW - last glacial maximum KW - Beaufort Sea coast KW - Cape Mamontov Klyk KW - permafrost carbon KW - Laptev Sea KW - Lyakhovsky Island KW - climate-change KW - old carbon KW - hologene KW - Siberia Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-408155 SN - 1866-8372 IS - 493 ER - TY - JOUR A1 - Fritz, Michael A1 - Opel, Thomas A1 - Tanski, George A1 - Herzschuh, Ulrike A1 - Meyer, H. A1 - Eulenburg, A. A1 - Lantuit, Hugues T1 - Dissolved organic carbon (DOC) in Arctic ground ice JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union N2 - Thermal permafrost degradation and coastal erosion in the Arctic remobilize substantial amounts of organic carbon (OC) and nutrients which have accumulated in late Pleistocene and Holocene unconsolidated deposits. Permafrost vulnerability to thaw subsidence, collapsing coastlines and irreversible landscape change are largely due to the presence of large amounts of massive ground ice such as ice wedges. However, ground ice has not, until now, been considered to be a source of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and other elements which are important for ecosystems and carbon cycling. Here we show, using biogeochemical data from a large number of different ice bodies throughout the Arctic, that ice wedges have the greatest potential for DOC storage, with a maximum of 28.6 mg L-1 (mean: 9.6 mg L-1). Variation in DOC concentration is positively correlated with and explained by the concentrations and relative amounts of typically terrestrial cations such as Mg2+ and K+. DOC sequestration into ground ice was more effective during the late Pleistocene than during the Holocene, which can be explained by rapid sediment and OC accumulation, the prevalence of more easily degradable vegetation and immediate incorporation into permafrost. We assume that pristine snowmelt is able to leach considerable amounts of well-preserved and highly bioavailable DOC as well as other elements from surface sediments, which are rapidly frozen and stored in ground ice, especially in ice wedges, even before further degradation. We found that ice wedges in the Yedoma region represent a significant DOC (45.2 Tg) and DIC (33.6 Tg) pool in permafrost areas and a freshwater reservoir of 4200 km(2). This study underlines the need to discriminate between particulate OC and DOC to assess the availability and vulnerability of the permafrost car-bon pool for ecosystems and climate feedback upon mobilization. Y1 - 2015 U6 - https://doi.org/10.5194/tc-9-737-2015 SN - 1994-0416 SN - 1994-0424 VL - 9 IS - 2 SP - 737 EP - 752 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Tanski, George A1 - Couture, Nicole A1 - Lantuit, Hugues A1 - Eulenburg, Antje A1 - Fritz, Michael T1 - Eroding permafrost coasts release low amounts of dissolved organic carbon (DOC) from ground ice into the nearshore zone of the Arctic Ocean JF - Global biogeochemical cycles N2 - Ice-rich permafrost coasts in the Arctic are highly sensitive to climate warming and erode at a pace that exceeds the global average. Permafrost coasts deliver vast amounts of organic carbon into the nearshore zone of the Arctic Ocean. Numbers on flux exist for particulate organic carbon (POC) and total or soil organic carbon (TOC, SOC). However, they do not exist for dissolved organic carbon (DOC), which is known to be highly bioavailable. This study aims to estimate DOC stocks in coastal permafrost as well as the annual flux into the ocean. DOC concentrations in ground ice were analyzed along the ice-rich Yukon coast (YC) in the western Canadian Arctic. The annual DOC flux was estimated using available numbers for coast length, cliff height, annual erosion rate, and volumetric ice content in different stratigraphic horizons. Our results showed that DOC concentrations in ground ice range between 0.3 and 347.0mgL(-1) with an estimated stock of 13.63.0gm(-3) along the YC. An annual DOC flux of 54.90.9Mgyr(-1) was computed. These DOC fluxes are low compared to POC and SOC fluxes from coastal erosion or POC and DOC fluxes from Arctic rivers. We conclude that DOC fluxes from permafrost coasts play a secondary role in the Arctic carbon budget. However, this DOC is assumed to be highly bioavailable. We hypothesize that DOC from coastal erosion is important for ecosystems in the Arctic nearshore zones, particularly in summer when river discharge is low, and in areas where rivers are absent. KW - Arctic KW - permafrost KW - coastal erosion KW - biogeochemistry KW - carbon cycle Y1 - 2016 U6 - https://doi.org/10.1002/2015GB005337 SN - 0886-6236 SN - 1944-9224 VL - 30 SP - 1054 EP - 1068 PB - American Geophysical Union CY - Cambridge ER - TY - THES A1 - Tanski, George T1 - Fate of organic matter mobilized from eroding permafrost coasts Y1 - 2017 ER - TY - JOUR A1 - Tanski, George A1 - Bergstedt, Helena A1 - Bevington, Alexandre A1 - Bonnaventure, Philip A1 - Bouchard, Frederic A1 - Coch, Caroline A1 - Dumais, Simon A1 - Evgrafova, Alevtina A1 - Frauenfeld, Oliver W. A1 - Frederick, Jennifer A1 - Fritz, Michael A1 - Frolov, Denis A1 - Harder, Silvie A1 - Hartmeyer, Ingo A1 - Heslop, Joanne A1 - Hoegstroem, Elin A1 - Johansson, Margareta A1 - Kraev, Gleb A1 - Kuznetsova, Elena A1 - Lenz, Josefine A1 - Lupachev, Alexey A1 - Magnin, Florence A1 - Martens, Jannik A1 - Maslakov, Alexey A1 - Morgenstern, Anne A1 - Nieuwendam, Alexandre A1 - Oliva, Marc A1 - Radosavljevi, Boris A1 - Ramage, Justine Lucille A1 - Schneider, Andrea A1 - Stanilovskaya, Julia A1 - Strauss, Jens A1 - Trochim, Erin A1 - Vecellio, Daniel J. A1 - Weber, Samuel A1 - Lantuit, Hugues T1 - The Permafrost Young Researchers Network (PYRN) is getting older BT - The past, present, and future of our evolving community JF - Polar record N2 - A lasting legacy of the International Polar Year (IPY) 2007–2008 was the promotion of the Permafrost Young Researchers Network (PYRN), initially an IPY outreach and education activity by the International Permafrost Association (IPA). With the momentum of IPY, PYRN developed into a thriving network that still connects young permafrost scientists, engineers, and researchers from other disciplines. This research note summarises (1) PYRN’s development since 2005 and the IPY’s role, (2) the first 2015 PYRN census and survey results, and (3) PYRN’s future plans to improve international and interdisciplinary exchange between young researchers. The review concludes that PYRN is an established network within the polar research community that has continually developed since 2005. PYRN’s successful activities were largely fostered by IPY. With >200 of the 1200 registered members active and engaged, PYRN is capitalising on the availability of social media tools and rising to meet environmental challenges while maintaining its role as a successful network honouring the legacy of IPY. KW - Early-career scientists KW - Education KW - IPY KW - International Polar Year KW - Outreach KW - Permafrost Young Researchers Network KW - PYRN KW - Science communication Y1 - 2019 U6 - https://doi.org/10.1017/S0032247418000645 SN - 0032-2474 SN - 1475-3057 VL - 55 IS - 4 SP - 216 EP - 219 PB - Cambridge Univ. Press CY - New York ER - TY - JOUR A1 - Tanski, George A1 - Lantuit, Hugues A1 - Ruttor, Saskia A1 - Knoblauch, Christian A1 - Radosavljevic, Boris A1 - Strauß, Jens A1 - Wolter, Juliane A1 - Irrgang, Anna Maria A1 - Ramage, Justine Lucille A1 - Fritz, Michael T1 - Transformation of terrestrial organic matter along thermokarst-affected permafrost coasts in the Arctic JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - The changing climate in the Arctic has a profound impact on permafrost coasts, which are subject to intensified thermokarst formation and erosion. Consequently, terrestrial organic matter (OM) is mobilized and transported into the nearshore zone. Yet, little is known about the fate of mobilized OM before and after entering the ocean. In this study we investigated a retrogressive thaw slump (RTS) on Qikiqtaruk - Herschel Island (Yukon coast, Canada). The RTS was classified into an undisturbed, a disturbed (thermokarst-affected) and a nearshore zone and sampled systematically along transects. Samples were analyzed for total and dissolved organic carbon and nitrogen (TOC, DOC, TN, DN), stable carbon isotopes (delta C-13-TOC, delta C-13-DOC), and dissolved inorganic nitrogen (DIN), which were compared between the zones. C/N-ratios, delta C-13 signatures, and ammonium (NH4-N) concentrations were used as indicators for OM degradation along with biomarkers (n-alkanes, n-fatty adds, n-alcohols). Our results show that OM significantly decreases after disturbance with a TOC and DOC loss of 77 and 55% and a TN and DN loss of 53 and 48%, respectively. C/N-ratios decrease significantly, whereas NH4-N concentrations slightly increase in freshly thawed material. In the nearshore zone, OM contents are comparable to the disturbed zone. We suggest that the strong decrease in OM is caused by initial dilution with melted massive ice and immediate offshore transport via the thaw stream. In the mudpool and thaw stream, OM is subject to degradation, whereas in the slump floor the nitrogen decrease is caused by recolonizing vegetation. Within the nearshore zone of the ocean, heavier portions of OM are directly buried in marine sediments close to shore. We conclude that RTS have profound impacts on coastal environments in the Arctic. They mobilize nutrients from permafrost, substantially decrease OM contents and provide fresh water and nutrients at a point source. KW - Canadian Arctic KW - Coastal erosion KW - Retrogressive thaw slump KW - Biogeochemistry KW - Carbon degradation Y1 - 2017 U6 - https://doi.org/10.1016/j.scitotenv.2016.12.152 SN - 0048-9697 SN - 1879-1026 VL - 581 SP - 434 EP - 447 PB - Elsevier Science CY - Amsterdam ER -