@article{TreatKleinenBroothaertsetal.2019, author = {Treat, Claire C. and Kleinen, Thomas and Broothaerts, Nils and Dalton, April S. and Dommain, Rene and Douglas, Thomas A. and Drexler, Judith Z. and Finkelstein, Sarah A. and Grosse, Guido and Hope, Geoffrey and Hutchings, Jack and Jones, Miriam C. and Kuhry, Peter and Lacourse, Terri and Lahteenoja, Outi and Loisel, Julie and Notebaert, Bastiaan and Payne, Richard J. and Peteet, Dorothy M. and Sannel, A. Britta K. and Stelling, Jonathan M. and Strauss, Jens and Swindles, Graeme T. and Talbot, Julie and Tarnocai, Charles and Verstraeten, Gert and Williams, Christopher J. and Xia, Zhengyu and Yu, Zicheng and Valiranta, Minna and Hattestrand, Martina and Alexanderson, Helena and Brovkin, Victor}, title = {Widespread global peatland establishment and persistence over the last 130,000 y}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {11}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1813305116}, pages = {4822 -- 4827}, year = {2019}, abstract = {Glacial-interglacial variations in CO2 and methane in polar ice cores have been attributed, in part, to changes in global wetland extent, but the wetland distribution before the Last Glacial Maximum (LGM, 21 ka to 18 ka) remains virtually unknown. We present a study of global peatland extent and carbon (C) stocks through the last glacial cycle (130 ka to present) using a newly compiled database of 1,063 detailed stratigraphic records of peat deposits buried by mineral sediments, as well as a global peatland model. Quantitative agreement between modeling and observations shows extensive peat accumulation before the LGM in northern latitudes (> 40 degrees N), particularly during warmer periods including the last interglacial (130 ka to 116 ka, MIS 5e) and the interstadial (57 ka to 29 ka, MIS 3). During cooling periods of glacial advance and permafrost formation, the burial of northern peatlands by glaciers and mineral sediments decreased active peatland extent, thickness, and modeled C stocks by 70 to 90\% from warmer times. Tropical peatland extent and C stocks show little temporal variation throughout the study period. While the increased burial of northern peats was correlated with cooling periods, the burial of tropical peat was predominately driven by changes in sea level and regional hydrology. Peat burial by mineral sediments represents a mechanism for long-term terrestrial C storage in the Earth system. These results show that northern peatlands accumulate significant C stocks during warmer times, indicating their potential for C sequestration during the warming Anthropocene.}, language = {en} } @article{TanskiLantuitRuttoretal.2017, author = {Tanski, George and Lantuit, Hugues and Ruttor, Saskia and Knoblauch, Christian and Radosavljevic, Boris and Strauß, Jens and Wolter, Juliane and Irrgang, Anna Maria and Ramage, Justine Lucille and Fritz, Michael}, title = {Transformation of terrestrial organic matter along thermokarst-affected permafrost coasts in the Arctic}, series = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, volume = {581}, journal = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man}, publisher = {Elsevier Science}, address = {Amsterdam}, issn = {0048-9697}, doi = {10.1016/j.scitotenv.2016.12.152}, pages = {434 -- 447}, year = {2017}, abstract = {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.}, language = {en} } @article{AngelopoulosOverduinWestermannetal.2020, author = {Angelopoulos, Michael and Overduin, Pier Paul and Westermann, Sebastian and Tronicke, Jens and Strauss, Jens and Schirrmeister, Lutz and Biskaborn, Boris K. and Liebner, Susanne and Maksimov, Georgii and Grigoriev, Mikhail N. and Grosse, Guido}, title = {Thermokarst lake to lagoon transitions in Eastern Siberia}, series = {Journal of geophysical research : Earth surface}, volume = {125}, journal = {Journal of geophysical research : Earth surface}, number = {10}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9003}, doi = {10.1029/2019JF005424}, pages = {21}, year = {2020}, abstract = {As the Arctic coast erodes, it drains thermokarst lakes, transforming them into lagoons, and, eventually, integrates them into subsea permafrost. Lagoons represent the first stage of a thermokarst lake transition to a marine setting and possibly more saline and colder upper boundary conditions. In this research, borehole data, electrical resistivity surveying, and modeling of heat and salt diffusion were carried out at Polar Fox Lagoon on the Bykovsky Peninsula, Siberia. Polar Fox Lagoon is a seasonally isolated water body connected to Tiksi Bay through a channel, leading to hypersaline waters under the ice cover. The boreholes in the center of the lagoon revealed floating ice and a saline cryotic bed underlain by a saline cryotic talik, a thin ice-bearing permafrost layer, and unfrozen ground. The bathymetry showed that most of the lagoon had bedfast ice in spring. In bedfast ice areas, the electrical resistivity profiles suggested that an unfrozen saline layer was underlain by a thick layer of refrozen talik. The modeling showed that thermokarst lake taliks can refreeze when submerged in saltwater with mean annual bottom water temperatures below or slightly above 0 degrees C. This occurs, because the top-down chemical degradation of newly formed ice-bearing permafrost is slower than the refreezing of the talik. Hence, lagoons may precondition taliks with a layer of ice-bearing permafrost before encroachment by the sea, and this frozen layer may act as a cap on gas migration out of the underlying talik.}, language = {en} } @article{TanskiBergstedtBevingtonetal.2019, author = {Tanski, George and Bergstedt, Helena and Bevington, Alexandre and Bonnaventure, Philip and Bouchard, Frederic and Coch, Caroline and Dumais, Simon and Evgrafova, Alevtina and Frauenfeld, Oliver W. and Frederick, Jennifer and Fritz, Michael and Frolov, Denis and Harder, Silvie and Hartmeyer, Ingo and Heslop, Joanne and Hoegstroem, Elin and Johansson, Margareta and Kraev, Gleb and Kuznetsova, Elena and Lenz, Josefine and Lupachev, Alexey and Magnin, Florence and Martens, Jannik and Maslakov, Alexey and Morgenstern, Anne and Nieuwendam, Alexandre and Oliva, Marc and Radosavljevi, Boris and Ramage, Justine Lucille and Schneider, Andrea and Stanilovskaya, Julia and Strauss, Jens and Trochim, Erin and Vecellio, Daniel J. and Weber, Samuel and Lantuit, Hugues}, title = {The Permafrost Young Researchers Network (PYRN) is getting older}, series = {Polar record}, volume = {55}, journal = {Polar record}, number = {4}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {0032-2474}, doi = {10.1017/S0032247418000645}, pages = {216 -- 219}, year = {2019}, abstract = {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.}, language = {en} } @article{StraussSchirrmeisterMangelsdorfetal.2015, author = {Strauss, Jens and Schirrmeister, Lutz and Mangelsdorf, Kai and Eichhorn, L. and Wetterich, Sebastian and Herzschuh, Ulrike}, title = {Organic-matter quality of deep permafrost carbon - a study from Arctic Siberia}, series = {Biogeosciences}, volume = {12}, journal = {Biogeosciences}, number = {7}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1726-4170}, doi = {10.5194/bg-12-2227-2015}, pages = {2227 -- 2245}, year = {2015}, abstract = {The organic-carbon (OC) pool accumulated in Arctic permafrost (perennially frozen ground) equals the carbon stored in the modern atmosphere. To give an idea of how Yedoma region permafrost could respond under future climatic warming, we conducted a study to quantify the organic-matter quality (here defined as the intrinsic potential to be further transformed, decomposed, and mineralized) of late Pleistocene (Yedoma) and Holocene (thermokarst) deposits on the Buor-Khaya Peninsula, northeast Siberia. The objective of this study was to develop a stratigraphic classified organic-matter quality characterization. For this purpose the degree of organic-matter decomposition was estimated by using a multiproxy approach. We applied sedimentological (grain-size analyses, bulk density, ice content) and geochemical parameters (total OC, stable carbon isotopes (delta C-13),total organic carbon : nitrogen (C / N) ratios) as well as lipid biomarkers (n-alkanes, n-fatty acids, hopanes, triterpenoids, and biomarker indices, i.e., average chain length, carbon preference index (CPI), and higher-plant fatty-acid index (HPFA)). Our results show that the Yedoma and thermokarst organic-matter qualities for further decomposition exhibit no obvious degradation-depth trend. Relatively, the C / N and delta C-13 values and the HPFA index show a significantly better preservation of the organic matter stored in thermokarst deposits compared to Yedoma deposits. The CPI data suggest less degradation of the organic matter from both deposits, with a higher value for Yedoma organic matter. As the interquartile ranges of the proxies mostly over-lap, we interpret this as indicating comparable quality for further decomposition for both kinds of deposits with likely better thermokarst organic-matter quality. Supported by principal component analyses, the sediment parameters and quality proxies of Yedoma and thermokarst deposits could not be unambiguously separated from each other. This revealed that the organic-matter vulnerability is heterogeneous and depends on different decomposition trajectories and the previous decomposition and preservation history. Elucidating this was one of the major new contributions of our multiproxy study. With the addition of biomarker data, it was possible to show that permafrost organic-matter degradation likely occurs via a combination of (uncompleted) degradation cycles or a cascade of degradation steps rather than as a linear function of age or sediment facies. We conclude that the amount of organic matter in the studied sediments is high for mineral soils and of good quality and therefore susceptible to future decomposition. The lack of depth trends shows that permafrost acts like a giant freezer, preserving the constant quality of ancient organic matter. When undecomposed Yedoma organic matter is mobilized via thermokarst processes, the fate of this carbon depends largely on the environmental conditions; the carbon could be preserved in an undecomposed state till refreezing occurs. If modern input has occurred, thermokarst organic matter could be of a better quality for future microbial decomposition than that found in Yedoma deposits.}, language = {en} } @article{JongejansStraussLenzetal.2018, author = {Jongejans, Loeka L. and Strauss, Jens and Lenz, Josefine and Peterse, Francien and Mangelsdorf, Kai and Fuchs, Matthias and Grosse, Guido}, title = {Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska}, series = {Biogeosciences}, volume = {15}, journal = {Biogeosciences}, number = {20}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1726-4170}, doi = {10.5194/bg-15-6033-2018}, pages = {6033 -- 6048}, year = {2018}, abstract = {As Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes. This study presents OM data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in west Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the below-ground OC pool size and OM quality of ice-rich permafrost on the Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three-quarters of soil OC in the frozen deposits of the study region (total of 68 Mt) is stored in DTLB deposits (52 Mt) and one-quarter in the frozen yedoma deposits (16 Mt). The lake sediments contain a relatively small OC pool (4 Mt), but have the highest volumetric OC content (93 kgm(-3)) compared to the DTLB (35 kgm(-3)) and yedoma deposits (8 kgm(-3)), largely due to differences in the ground ice content. The biomarker analysis indicates that the OM in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of a degradation trend with depth in the yedoma deposits indi-cates that OM stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OM in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings show that the use of lipid biomarker analysis is valuable in the assessment of the potential future greenhouse gas emissions from thawing permafrost, especially because this area, close to the discontinuous permafrost boundary, is projected to thaw substantially within the 21st century.}, language = {en} } @article{FuchsLenzJocketal.2019, author = {Fuchs, Matthias and Lenz, Josefine and Jock, Suzanne and Nitze, Ingmar and Jones, Benjamin M. and Strauss, Jens and G{\"u}nther, Frank and Grosse, Guido}, title = {Organic carbon and nitrogen stocks along a thermokarst lake sequence in Arctic Alaska}, series = {Journal of geophysical research : Biogeosciences}, volume = {124}, journal = {Journal of geophysical research : Biogeosciences}, number = {5}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-8953}, doi = {10.1029/2018JG004591}, pages = {1230 -- 1247}, year = {2019}, abstract = {Thermokarst lake landscapes are permafrost regions, which are prone to rapid (on seasonal to decadal time scales) changes, affecting carbon and nitrogen cycles. However, there is a high degree of uncertainty related to the balance between carbon and nitrogen cycling and storage. We collected 12 permafrost soil cores from six drained thermokarst lake basins (DTLBs) along a chronosequence north of Teshekpuk Lake in northern Alaska and analyzed them for carbon and nitrogen contents. For comparison, we included three lacustrine cores from an adjacent thermokarst lake and one soil core from a non thermokarst affected remnant upland. This allowed to calculate the carbon and nitrogen stocks of the three primary landscape units (DTLB, lake, and upland), to reconstruct the landscape history, and to analyze the effect of thermokarst lake formation and drainage on carbon and nitrogen stocks. We show that carbon and nitrogen contents and the carbon-nitrogen ratio are considerably lower in sediments of extant lakes than in the DTLB or upland cores indicating degradation of carbon during thermokarst lake formation. However, we found similar amounts of total carbon and nitrogen stocks due to the higher density of lacustrine sediments caused by the lack of ground ice compared to DTLB sediments. In addition, the radiocarbon-based landscape chronology for the past 7,000years reveals five successive lake stages of partially, spatially overlapping DTLBs in the study region, reflecting the dynamic nature of ice-rich permafrost deposits. With this study, we highlight the importance to include these dynamic landscapes in future permafrost carbon feedback models. Plain Language Summary When permanently frozen soils (permafrost) contain ice-rich sediments, the thawing of this permafrost causes the surface to sink, which may result in lake formation. This process, the thaw of ice-rich permafrost and melting of ground ice leads to characteristic landforms-known as thermokarst. Once such a thaw process is initiated in ice-rich sediments, a thaw lake forms and grows by shoreline erosion, eventually expanding until a drainage pathway is encountered and the lake eventually drains, resulting in a drained thermokarst lake basin. In our study, we show that such a thermokarst-affected landscape north of Teshekpuk Lake in northern Alaska is shaped by repeated thaw lake formation and lake drainage events during the past 7,000years, highlighting the dynamic nature of these landscapes. These landscape-scale processes have a big effect on the carbon and nitrogen stored in permafrost soils. We show that large amounts of carbon (>45kg C/m(2)) and nitrogen (>2.6kg N/m(2)) are stored in unfrozen lake sediments and in frozen soil sediments. The findings are important when considering the potential effect that permafrost thaw has for the global climate through releasing carbon and nitrogen, which was frozen and therefore locked away for millennia, from the active carbon cycle.}, language = {en} } @article{SchirrmeisterBobrovRaschkeetal.2018, author = {Schirrmeister, Lutz and Bobrov, Anatoly and Raschke, Elena and Herzschuh, Ulrike and Strauss, Jens and Pestryakova, Luidmila Agafyevna and Wetterich, Sebastian}, title = {Late Holocene ice-wedge polygon dynamics in northeastern Siberian coastal lowlands}, series = {Arctic, antarctic, and alpine research : an interdisciplinary journal}, volume = {50}, journal = {Arctic, antarctic, and alpine research : an interdisciplinary journal}, number = {1}, publisher = {Institute of Arctic and Alpine Research, University of Colorado}, address = {Boulder}, issn = {1523-0430}, doi = {10.1080/15230430.2018.1462595}, pages = {18}, year = {2018}, abstract = {Ice-wedge polygons are common features of northeastern Siberian lowland periglacial tundra landscapes. To deduce the formation and alternation of ice-wedge polygons in the Kolyma Delta and in the Indigirka Lowland, we studied shallow cores, up to 1.3 m deep, from polygon center and rim locations. The formation of well-developed low-center polygons with elevated rims and wet centers is shown by the beginning of peat accumulation, increased organic matter contents, and changes in vegetation cover from Poaceae-, Alnus-, and Betula-dominated pollen spectra to dominating Cyperaceae and Botryoccocus presence, and Carex and Drepanocladus revolvens macro-fossils. Tecamoebae data support such a change from wetland to open-water conditions in polygon centers by changes from dominating eurybiontic and sphagnobiontic to hydrobiontic species assemblages. The peat accumulation indicates low-center polygon formation and started between 2380 +/- 30 and 1676 +/- 32 years before present (BP) in the Kolyma Delta. We recorded an opposite change from open-water to wetland conditions because of rim degradation and consecutive high-center polygon formation in the Indigirka Lowland between 2144 +/- 33 and 1632 +/- 32 years BP. The late Holocene records of polygon landscape development reveal changes in local hydrology and soil moisture.}, language = {en} } @article{MonhonvalStraussMaucletetal.2021, author = {Monhonval, Arthur and Strauss, Jens and Mauclet, Elisabeth and Hirst, Catherine and Bemelmans, Nathan and Grosse, Guido and Schirrmeister, Lutz and Fuchs, Matthias and Opfergelt, Sophie}, title = {Iron redistribution upon thermokarst processes in the Yedoma domain}, series = {Frontiers in Earth Science}, volume = {9}, journal = {Frontiers in Earth Science}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-6463}, doi = {10.3389/feart.2021.703339}, pages = {18}, year = {2021}, abstract = {Ice-rich permafrost has been subject to abrupt thaw and thermokarst formation in the past and is vulnerable to current global warming. The ice-rich permafrost domain includes Yedoma sediments that have never thawed since deposition during the late Pleistocene and Alas sediments that were formed by previous thermokarst processes during the Lateglacial and Holocene warming. Permafrost thaw unlocks organic carbon (OC) and minerals from these deposits and exposes OC to mineralization. A portion of the OC can be associated with iron (Fe), a redox-sensitive element acting as a trap for OC. Post-depositional thaw processes may have induced changes in redox conditions in these deposits and thereby affected Fe distribution and interactions between OC and Fe, with knock-on effects on the role that Fe plays in mediating present day OC mineralization. To test this hypothesis, we measured Fe concentrations and proportion of Fe oxides and Fe complexed with OC in unthawed Yedoma and previously thawed Alas deposits. Total Fe concentrations were determined on 1,292 sediment samples from the Yedoma domain using portable X-ray fluorescence; these concentrations were corrected for trueness using a calibration based on a subset of 144 samples measured by inductively coupled plasma optical emission spectrometry after alkaline fusion (R (2) = 0.95). The total Fe concentration is stable with depth in Yedoma deposits, but we observe a depletion or accumulation of total Fe in Alas deposits, which experienced previous thaw and/or flooding events. Selective Fe extractions targeting reactive forms of Fe on unthawed and previously thawed deposits highlight that about 25\% of the total Fe is present as reactive species, either as crystalline or amorphous oxides, or complexed with OC, with no significant difference in proportions of reactive Fe between Yedoma and Alas deposits. These results suggest that redox driven processes during past thermokarst formation impact the present-day distribution of total Fe, and thereby the total amount of reactive Fe in Alas versus Yedoma deposits. This study highlights that ongoing thermokarst lake formation and drainage dynamics in the Arctic influences reactive Fe distribution and thereby interactions between Fe and OC, OC mineralization rates, and greenhouse gas emissions.}, language = {en} } @article{WetterichRudayaKuznetsovetal.2019, author = {Wetterich, Sebastian and Rudaya, Natalia and Kuznetsov, Vladislav and Maksimov, Fedor and Opel, Thomas and Meyer, Hanno and G{\"u}nther, Frank and Bobrov, Anatoly and Raschke, Elena and Zimmermann, Heike Hildegard and Strauss, Jens and Starikova, Anna and Fuchs, Margret and Schirrmeister, Lutz}, title = {Ice Complex formation on Bol'shoy Lyakhovsky Island (New Siberian Archipelago, East Siberian Arctic) since about 200 ka}, series = {Quaternary research : an interdisciplinary journal}, volume = {92}, journal = {Quaternary research : an interdisciplinary journal}, number = {2}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {0033-5894}, doi = {10.1017/qua.2019.6}, pages = {530 -- 548}, year = {2019}, abstract = {Late Quaternary landscapes of unglaciated Beringia were largely shaped by ice-wedge polygon tundra. Ice Complex (IC) strata preserve such ancient polygon formations. Here we report on the Yukagir IC from Bol'shoy Lyakhovsky Island in northeastern Siberia and suggest that new radioisotope disequilibria (230Th/U) dates of the Yukagir IC peat confirm its formation during the Marine Oxygen Isotope Stage (MIS) 7a-c interglacial period. The preservation of the ice-rich Yukagir IC proves its resilience to last interglacial and late glacial-Holocene warming. This study compares the Yukagir IC to IC strata of MIS 5, MIS 3, and MIS 2 ages exposed on Bol'shoy Lyakhovsky Island. Besides high intrasedimental ice content and syngenetic ice wedges intersecting silts, sandy silts, the Yukagir IC is characterized by high organic matter (OM) accumulation and low OM decomposition of a distinctive Drepanocladus moss-peat. The Yukagir IC pollen data reveal grass-shrub-moss tundra indicating rather wet summer conditions similar to modern ones. The stable isotope composition of Yukagir IC wedge ice is similar to those of the MIS 5 and MIS 3 ICs pointing to similar atmospheric moisture generation and transport patterns in winter. IC data from glacial and interglacial periods provide insights into permafrost and climate dynamics since about 200 ka.}, language = {en} }