@article{JonesArpWhitmanetal.2017, author = {Jones, Benjamin M. and Arp, Christopher D. and Whitman, Matthew S. and Nigro, Debora and Nitze, Ingmar and Beaver, John and Gadeke, Anne and Zuck, Callie and Liljedahl, Anna and Daanen, Ronald and Torvinen, Eric and Fritz, Stacey and Grosse, Guido}, title = {A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska experiencing climate and land-use changes}, series = {AMBIO}, volume = {46}, journal = {AMBIO}, publisher = {Springer}, address = {Dordrecht}, issn = {0044-7447}, doi = {10.1007/s13280-017-0915-9}, pages = {769 -- 786}, year = {2017}, abstract = {Lakes are dominant and diverse landscape features in the Arctic, but conventional land cover classification schemes typically map them as a single uniform class. Here, we present a detailed lake-centric geospatial database for an Arctic watershed in northern Alaska. We developed a GIS dataset consisting of 4362 lakes that provides information on lake morphometry, hydrologic connectivity, surface area dynamics, surrounding terrestrial ecotypes, and other important conditions describing Arctic lakes. Analyzing the geospatial database relative to fish and bird survey data shows relations to lake depth and hydrologic connectivity, which are being used to guide research and aid in the management of aquatic resources in the National Petroleum Reserve in Alaska. Further development of similar geospatial databases is needed to better understand and plan for the impacts of ongoing climate and land-use changes occurring across lake-rich landscapes in the Arctic.}, language = {en} } @article{StraussSchirrmeisterGrosseetal.2017, author = {Strauss, Jens and Schirrmeister, Lutz and Grosse, Guido and Fortier, Daniel and Hugelius, Gustaf and Knoblauch, Christian and Romanovsky, Vladimir E. and Schadel, Christina and von Deimling, Thomas Schneider and Schuur, Edward A. G. and Shmelev, Denis and Ulrich, Mathias and Veremeeva, Alexandra}, title = {Deep Yedoma permafrost: A synthesis of depositional characteristics and carbon vulnerability}, series = {Earth science reviews : the international geological journal bridging the gap between research articles and textbooks}, volume = {172}, journal = {Earth science reviews : the international geological journal bridging the gap between research articles and textbooks}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-8252}, doi = {10.1016/j.earscirev.2017.07.007}, pages = {75 -- 86}, year = {2017}, abstract = {Permafrost is a distinct feature of the terrestrial Arctic and is vulnerable to climate warming. Permafrost degrades in different ways, including deepening of a seasonally unfrozen surface and localized but rapid development of deep thaw features. Pleistocene ice-rich permafrost with syngenetic ice-wedges, termed Yedoma deposits, are widespread in Siberia, Alaska, and Yukon, Canada and may be especially prone to rapid-thaw processes. Freeze-locked organic matter in such deposits can be re-mobilized on short time-scales and contribute to a carbon-cycle climate feedback. Here we synthesize the characteristics and vulnerability of Yedoma deposits by synthesizing studies on the Yedoma origin and the associated organic carbon pool. We suggest that Yedoma deposits accumulated under periglacial weathering, transport, and deposition dynamics in non-glaciated regions during the late Pleistocene until the beginning of late glacial warming. The deposits formed due to a combination of aeolian, colluvial, nival, and alluvial deposition and simultaneous ground ice accumulation. We found up to 130 gigatons organic carbon in Yedoma, parts of which are well-preserved and available for fast decomposition after thaw. Based on incubation experiments, up to 10\% of the Yedoma carbon is considered especially decomposable and may be released upon thaw. The substantial amount of ground ice in Yedoma makes it highly vulnerable to disturbances such as thermokarst and thermo-erosion processes. Mobilization of permafrost carbon is expected to increase under future climate warming. Our synthesis results underline the need of accounting for Yedoma carbon stocks in next generation Earth-System-Models for a more complete representation of the permafrost-carbon feedback.}, language = {en} } @article{MonhonvalStraussThomasetal.2022, author = {Monhonval, Arthur and Strauss, Jens and Thomas, Maxime and Hirst, Catherine and Titeux, Hugues and Louis, Justin and Gilliot, Alexia and D'Aische, Eleonore du Bois and Pereira, Benoit and Vandeuren, Aubry and Grosse, Guido and Schirrmeister, Lutz and Jongejans, Loeka Laura and Ulrich, Mathias and Opfergelt, Sophie}, title = {Thermokarst processes increase the supply of stabilizing surfaces and elements (Fe, Mn, Al, and Ca) for mineral-organic carbon interactions}, series = {Permafrost and periglacial processes}, volume = {33}, journal = {Permafrost and periglacial processes}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {1045-6740}, doi = {10.1002/ppp.2162}, pages = {452 -- 469}, year = {2022}, abstract = {The stabilizing properties of mineral-organic carbon (OC) interactions have been studied in many soil environments (temperate soils, podzol lateritic soils, and paddy soils). Recently, interest in their role in permafrost regions is increasing as permafrost was identified as a hotspot of change. In thawing ice-rich permafrost regions, such as the Yedoma domain, 327-466 Gt of frozen OC is buried in deep sediments. Interactions between minerals and OC are important because OC is located very near the mineral matrix. Mineral surfaces and elements could mitigate recent and future greenhouse gas emissions through physical and/or physicochemical protection of OC. The dynamic changes in redox and pH conditions associated with thermokarst lake formation and drainage trigger metal-oxide dissolution and precipitation, likely influencing OC stabilization and microbial mineralization. However, the influence of thermokarst processes on mineral-OC interactions remains poorly constrained. In this study, we aim to characterize Fe, Mn, Al, and Ca minerals and their potential protective role for OC. Total and selective extractions were used to assess the crystalline and amorphous oxides or complexed metal pools as well as the organic acids found within these pools. We analyzed four sediment cores from an ice-rich permafrost area in Central Yakutia, which were drilled (i) in undisturbed Yedoma uplands, (ii) beneath a recent lake formed within Yedoma deposits, (iii) in a drained thermokarst lake basin, and (iv) beneath a mature thermokarst lake from the early Holocene period. We find a decrease in the amount of reactive Fe, Mn, Al, and Ca in the deposits on lake formation (promoting reduction reactions), and this was largely balanced by an increase in the amount of reactive metals in the deposits on lake drainage (promoting oxidation reactions). We demonstrate an increase in the metal to C molar ratio on thermokarst process, which may indicate an increase in metal-C bindings and could provide a higher protective role against microbial mineralization of organic matter. Finally, we find that an increase in mineral-OC interactions corresponded to a decrease in CO2 and CH4 gas emissions on thermokarst process. Mineral-OC interactions could mitigate greenhouse gas production from permafrost thaw as soon as lake drainage occurs.}, language = {en} }