Description: This dataset compiles selected limnological properties of a series of thermokarst (thaw) lakes in Central Yakutia (Eastern Siberia). These properties were measured during fall 2018 (September), winter 2019 (March-April), spring 2019 (May), and summer 2019 (August). These data span four seasons (Fall, Winter, Spring, and Summer) 2018-2019. The lake type designation is based on field observations, past radiocarbon dating of lake sediments, geochemical signatures of lake waters, and a multiple-stage development model of thermokarst lakes. Data were collected at the surface (~ 30 cm depth) from lake shores. Specific conductivity (accuracy ±1% of reading), temperature (accuracy ±0.2°C), dissolved oxygen (accuracy ±1% of reading or 1% saturation) and pH (accuracy ±0.2) were measured using a YSI Pro DSS multiprobe sensor. Water samples were collected to analyze dissolved organic carbon (DOC). Samples were filtered using baked glass fiber filters (Whatman GF/F, 0. 7µm), acidified to pH 2 with ultra-pure HCl and stored in baked glass vials. DOC concentration was measured using a TOC-5000A analyzer (Shimadzu, Japan). The quantification limit was 1 mg L-1. Above this value, the analytical uncertainty was estimated at ±0.1 mg L-1. Reference material included ION-915 ([DOC]= 1.37 ± 0.41mg C L-1) and ION 96.4 ([DOC]= 4.64 ± 0.70 mg C L-1) (Environment and Climate Change Canada, Canada).

Description: Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1.0 × 10**4 m**2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002-2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1.4 × 10**6 km**2 across the Arctic, about 17 % of the Arctic lowland ( 〈 300 m a.s.l.) land surface area. PeRL waterbodies with sizes of 1.0 × 10**6 m**2 down to 1.0 × 10**2 m**2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1.0 × 10 to 9.4 × 10**1/km². Ponds are the dominant waterbody type by number in all landscapes representing 45-99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands.

Description: Eight overlapping sediment cores, representing an approximately 6.6 m–long composite sequence, were collected on March 24, 2013 from Lake Malaya Chabyda in Central Yakutia (exact coring location 61°57.509' 129°24.500'). Sampling was conducted during a German–Russian Expedition (“Yakutia 2013”) as a cooperation between the North Eastern Federal State University in Yakutsk (NEFU) and the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI). To penetrate ca. 1 m of lake ice cover, 250-mm-diameter holes were drilled using a hand-held Jiffy ice auger. Water depth was measured using an Echo sounder (HONDEX PS-7 LCD) and a calibrated rope for verification. 100 cm-long parallel cores were collected at 2 m water depth using a Russian peat corer and supported by an UWITEC gravity coring system. Cores were stored in waterproof sealed, transparent PVC plastic tubes in cool and dark conditions. After the field season, the cores were transported to Potsdam, Germany and stored at 4°C in the cold rooms at AWI. The cores did not experience any visible drying or surface oxidation during storage. High–resolution X–ray fluorescence (XRF) analyses were carried out with 10 mm resolution on the entire sequence using an Avaatech XRF core scanner at AWI (Bremerhaven, Germany) with a Rh X-ray tube at 10 kV (without filter, 12 s, 1.5 mA) and 30 kV (Pd-thick filer, 15 s, 1.2 mA). The sediment surface was cleaned, leveled, and covered with a 4µm ultralene foil to avoid sediment desiccation prior to XRF scanning. Individual element counts per second (CPS) were transformed using a centered log transformation (CLR) and element ratios were transformed using an additive log ratio (ALR) to account for compositional data effects and reduce effects from variations in sample density, water content, and grain size. Statistical analysis was completed using the Python programming language (Python Software Foundation, https://www.python.org/). XRF analysis of the sequence indicated 24 detectable elements and a subset of these were selected for analysis based on low element χ2 values. These selected elements include the major rock forming elements of Silicon (Si) (Chi2 1.4), Calcium (Ca) (Chi2 6.3), Titanium (Ti) (Chi2 1.3), Rubidium (Rb) (Chi2 0.6), Strontium (Sr) (Chi2 0.7), Zircon (Zr) (Chi2 0.6) and the redox sensitive, productivity indicating elements of Manganese (Mn) (Chi2 1.3), Iron (Fe) (Chi2 2.5), and Bromine (Br) (Chi2 0.8). All subsequent analyses took place after the extracted subsamples had been freeze–dried until completely dry (approximately 48 hours). Grain size analysis was conducted on 18 samples that were chosen to span the entire sequence at relatively regular intervals. The samples were first treated for five weeks with H2O2 (0.88 M) in order to isolate clastic material. After treatment, seven samples were eliminated from the analysis because the remaining inorganic sediment fraction was too low for detection by the laser grain size analyzer. The remaining samples were homogenized using an elution shaker for 24 h and then analyzed using a Malvern Mastersizer 3000 laser. Standard statistical parameters (mean, median, mode, sorting, skewness, and kurtosis) were determined using GRADISTAT 9.1. Total carbon (TC), total organic carbon (TOC), and total nitrogen (TN) analyses were completed after the freeze–dried subsamples were ground in a Pulverisette 5 (Fritsch) planetary mill at 3000 rpm for 7 minutes. TC and TN were measured in a carbon–nitrogen–sulphur analyzer (Vario EL III, Elementar). Five mg of sample material were encapsulated in tin (Sn) capsules together with 10 mg of tungsten–(VI)–oxide. The tungsten–(VI)–oxide ensures complete oxidation of the sample during the measurement process. Duplicate capsules were prepared and measured for each subsample. Blanks and calibration standards were placed every 15 samples to ensure analytical accuracy (〈 ± 0.1 wt%). Between each sample spatula was cleaned with KIMTECK fuzz-free tissues and isopropyl. Analysis of TOC began by removing the inorganic carbon fraction by placing each subsample in a warm hydrochloric acid solution (1.3 molar) for at least three hours and then transferring the sample to a drying oven. The TC measured for each subsample in the previous analysis was used to determine the amount of sample required for the TOC analysis. The appropriate amount of sample was weighted in a ceramic crucible and analyzed using the Vario Max C, Elementar. The TOC/TN ratio was converted to the TOC/TNatomic ratio by multiplying the TOC/TN ratio by 1.167 (atomic weight of carbon and nitrogen). Total inorganic carbon (TIC) analysis was completed using a Vario SoilTOC cube elemental analyzer after combustion at 400ºC (TOC) and 900ºC (TIC) (Elementar Corp., Germany). Calculation of δ13C was completed twice for a subset of samples using two different methodologies. The analysis completed at the AWI Potsdam ISOLAB Facility removed carbonate by treating the samples with hydrogen chloride (12 M HCl) for three hours at 97 °C, then adding purified water and decanting and washed three times. Once the chloride content was below 500 parts per million (ppm), the samples were filtered over a glass microfiber (Whatman Grade GF/B, nominal particle retention of 1.0 µm). The residual sample was dried overnight in a drying cabinet at 50°C. The dry samples were manually ground for homogenization and weighted into tin capsules and analyzed using a ThermoFisher Scientific Delta–V–Advantage gas mass spectrometer equipped with a FLASH elemental analyzer EA 2000 and a CONFLO IV gas mixing system. In this system, the sample is combusted at 1020°C in O2 atmosphere so that the OC is quantitatively transferred to CO2, after which the isotope ratio is determined relative to a laboratory standard of known isotopic composition. Capsules for control and calibration were run in between. The isotope composition is given in permil (‰) relative to Vienna Pee Dee Belemnite (VPDB). The analysis of a small subset of samples which took place at Laboratoire des sciences du climat et de l'environnement Isotopic Laboratory for methodological comparison underwent a slightly different treatment, as follows. The sediment underwent a soft leaching process to remove carbonate using pre-combusted glass beakers, HCl 0.6N at room temperature, ultra-pure water and drying at 50 C. The samples were then crushed in a pre-combusted glass mortar for homogenization prior to carbon content and δ13 C analysis. The handling and chemical procedures are common precautions employed with low-carbon-content sediments. Analysis was performed online using a continuous flow EA-IRMS coupling, that is, a Fisons Instrument NA 1500 Element Analyzer coupled to a ThermoFinigan Delta+XP Isotope-Ratio Mass Spectrometer. Two in-house standards (oxalic acid, δ13C =−19.3% and GCL, _13C =−26.7 %) were inserted every five samples. Each in-house standard was regularly checked against international standards. The measurements were at least triplicated for representativeness. The external reproducibility of the analysis was better than 0.1 %, typically 0.06 %. Extreme values were checked twice. Those samples for which the carbonate was leeched at the room temperature, with lower HCl concentration (0.6N), and without a filtration step (samples analyzed at Laboratoire des sciences du climat et de l'environnement Isotopic Laboratory) had δ13C values 0.1‰ to 1.0‰ (average 0.5‰) higher than the samples treated at the higher temperature (97.7 ºC). However, the plotted δ13C curve is nearly identical for the subset of samples which were subjected to both treatments. There is some heterogeneity in the amount of offset between the two treatment methods. This might be related to an asymmetrical distribution of hot acid-soluble organic compounds throughout the sediment core. A correction of ca. +0.5‰ was applied to the results of the high temperature treatment. These values were then combined with the low temperature results to provide a complete dataset for the whole core. The standard deviation (1σ) is generally better than δ13C = ±0.15‰.

Description: Dieses Projekt startete im Oktober 2015 mit einer verrückten Idee: Schreiben und Einreichen eines Antrags auf Förderung einer internationalen, multidisziplinären und nicht-traditionell wissenschaftlichen Projektinitiative… innerhalb von 48 Stunden. Und es hat geklappt ! Eine Gruppe hoch motivierter, junger Forscher aus Kanada und Europa hat sich gebildet, um Kunst und Wissenschaft zu kombinieren und eine Reihe von Comics über Permafrost (gefrorene Böden) zu produzieren. Unser Ziel ist es, zu zeigen, wie wissenschaftliches Arbeiten im hohen Norden funktioniert, mit dem Schwerpunkt auf Geländearbeit und den schnellen Umweltveränderungen in der Arktis. Die Zielgruppe sind Kinder, Jugendliche, Eltern und Lehrer, mit dem allgemeinen Ziel, Permafrost zugänglicher und mit Spaß zu vermitteln. Denn ratet mal: Permafrost ist ein Gebiet von mehr als 20 Millionen km2 auf der Nordhalbkugel – ein riesiges Gebiet. Durch die Klimaerwärmung taut der Permafrost und wird zu instabil, um Häuser, Straßen und Flughäfen zu tragen. Durch das Auftauen von gefrorenem Boden werden außerdem Pflanzen- und Tierhabitate zerstört, die Wasserqualität und Ökologie von Seen beeinflusst und auf Grund der Freisetzung von Kohlenstoff als Treibhausgas in die Atmosphäre wird der Klimawandel sogar verstärkt. Daher betrifft Permafrost und seine Reaktion auf den Klimawandel uns alle. Die Internationale Permafrost Gemeinschaft (IPA) hat das Projekt als „Action Group“ von Beginn an unterstützt und seitdem sind noch viele weitere Sponsoren dazugekommen. Und hier sind wir nun: Zwei Jahre nach der ersten Idee. Ihr seid kurz davor das zu lesen, was das Ergebnis eines ständigen Austauschs zwischen Künstlern und Wissenschaftlern ist. Zunächst hatten wir eine Ausschreibungsrunde und erhielten 49 Bewerbungen von Künstlern aus 16 Ländern. Durch ein Bewertungsverfahren wählten wir zwei Künstlerinnen aus, um an diesem Projekt zu arbeiten: Noémie Ross aus Kanada und Heta Nääs aus Finnland. Mit den Beiträgen von Wissenschaftlern erstellten Noémie und Heta fantastische Cartoons, die ein paar der Veränderungen erklären, die in Permafrost-Gebieten passieren. Zum Beispiel: wie wird die Welt der Menschen und Tiere beeinflusst und was machen Forscher, um diese Prozesse besser zu verstehen, sodass sie den Einheimischen helfen können, innovative Wege zur Anpassung zu finden.

Description: Over the past two decades, the International Arctic Science Committee (IASC) and the Scientific Committee on Antarctic Research (SCAR) have organized activities focused on international and interdisciplinary perspectives for advancing Arctic and Antarctic research cooperation and knowledge dissemination in many areas (e.g. Kennicutt et al., 2014). For permafrost science, however, no consensus document exists at the international level to identify future research priorities, although the International Permafrost Association (IPA) highlighted the need for such a document during the 10th International Conference on Permafrost in 2012. Four years later, this presentation, which is based on the results obtained by Fritz et al. (2015), outlines the outcome of an international and interdisciplinary effort conducted by early career researchers (ECRs). This effort was designed as a contribution to the Third International Conference on Arctic Research Planning (ICARP III). In June 2014, 88 ERCs convened during the Fourth European Conference on Permafrost to identify future priorities for permafrost research. We aimed to meet our goals of hosting an effective large group dialogue by means of online question development followed by a “World Café” conversational process. An overview of the process is provided in Figure 1. This activity was organized by the two major early career researcher associations Permafrost Young Researchers’ Network (PYRN) and the Association of Polar Early career Scientists (APECS), as well as the regional research projects PAGE21 (EU) and ADAPT (Canada). Participants were provided with live instructions including criteria regarding what makes a research question (Sutherland et al., 2011). The top five questions that emerged from this process are: (1) How does permafrost degradation affect landscape dynamics at different spatial and temporal scales? (2) How can ground thermal models be improved to better reflect permafrost dynamics at high spatial resolution? (3) How can traditional environmental knowledge be integrated in permafrost research? (4) What is the spatial distribution of different ground-ice types and how susceptible is ice-rich permafrost to future environmental change? (5) What is the influence of infrastructures on the thermal regime and stability of permafrost in different environmental settings? As the next generation of permafrost researchers, we see the need and the opportunity to participate in framing the future research priorities. Across the polar sciences, ECRs have built powerful networks, such as the Association of Polar Early Career Scientists (APECS) and the Permafrost Young Researchers Network (PYRN), which have enabled us to efficiently consult with the community. Many participants of this community-input exercise will be involved in and also affected by the Arctic science priorities during the next decade. Therefore, we need to (i) contribute our insights into larger efforts of the community such as the Permafrost Research Priorities initiative by the Climate and Cryosphere (CliC) project together with the IPA and (ii) help identify relevant gaps and a suitable roadmap for the future of Arctic research. Critical evaluation of the progress made since ICARP II and revisiting the science plans and recommendations will be crucial. IASC and the IPA, together with SCAR on bipolar activities, should coordinate the research agendas in a proactive manner engaging all partners, including funding agencies, policy makers, and local communities. Communicating our main findings to society in a dialogue between researchers and the public is a priority. Special attention must be given to indigenous peoples living on permafrost, where knowledge exchange creates a mutual benefit for science and local communities. The ICARP III process is an opportunity to better communicate the global importance of permafrost to policy makers and the public.

Description: This project started in October 2015 with a crazy idea: prepare and submit a funding application for an international, multidisciplinary and non-traditional scientific outreach project… within the next 48 hours. Well, it worked out. A group of highly motivated young researchers from Canada and Europe united to combine arts and science and produce a series of outreach comic strips about permafrost (frozen ground). The aim of the project is to present and explain scientific research conducted across the circumpolar Arctic, placing emphasis on field work and the rapidly changing northern environment. The target audience is kids, youth, parents and teachers, with the general goal of making permafrost science more fun and accessible to the public. Because guess what : permafrost represents an area of more than twenty million km2 in the Northern Hemisphere, a huge area. As the climate warms, permafrost thaws and becomes unstable for houses, roads and airports. This rapid thawing of previously frozen ground also disrupts plant and animal habitats, impacts water quality and the ecology of lakes, and releases carbon into the atmosphere as greenhouse gases, making climate change even stronger. Hence permafrost and its response to climate change concerns us all. The project received initial support from the International Permafrost Association (IPA) as a targeted ‘Action Group’, and since then several other sponsors have joined the project. Here we are, now, two years after this first idea. What you are about to read is the result of an iterative process of exchanging ideas between artists and scientists. We first made an application call and received 49 applications from artists in 16 countries. Through a formal review process, we then selected two artists to work on this project: Noémie Ross from Canada, and Heta Nääs from Finland. With input from scientists, Noémie and Heta created fantastic cartoons that explain some of the changes happening to the environment in permafrost areas, how they affect people and wildlife, and what scientists are doing to better understand these changes to help people find innovative ways to adapt. We wish everyone plenty of fun reading this booklet and we would like to thank all those who supported this project.

Description: The Action Group called ‘Standardized methods across Permafrost Landscapes: from Arctic Soils to Hydrosystems’ (SPLASH) is a community-driven effort aiming to provide a suite of standardized field strategies for sampling mineral and organic components in soils, sediments, and water across permafrost landscapes. This unified approach will allow data from different landscape interfaces, field locations and seasons to be shared and compared, thus improving our understanding of the processes occurring during lateral transport in circumpolar Arctic watersheds.

Description: This project started in October 2015 with a crazy idea: prepare and submit a funding application for an international, multidisciplinary and non-traditional scientific outreach project… within the next 48 hours. Well, it worked out. A group of highly motivated young researchers from Canada and Europe united to combine arts and science and produce a series of outreach comic strips about permafrost (frozen ground). The aim of the project is to present and explain scientific research conducted across the circumpolar Arctic, placing emphasis on field work and the rapidly changing northern environment. The target audience is kids, youth, parents and teachers, with the general goal of making permafrost science more fun and accessible to the public. Because guess what : permafrost represents an area of more than twenty million km2 in the Northern Hemisphere, a huge area. As the climate warms, permafrost thaws and becomes unstable for houses, roads and airports. This rapid thawing of previously frozen ground also disrupts plant and animal habitats, impacts water quality and the ecology of lakes, and releases carbon into the atmosphere as greenhouse gases, making climate change even stronger. Hence permafrost and its response to climate change concerns us all. The project received initial support from the International Permafrost Association (IPA) as a targeted ‘Action Group’, and since then several other sponsors have joined the project. Here we are, now, two years after this first idea. What you are about to read is the result of an iterative process of exchanging ideas between artists and scientists. We first made an application call and received 49 applications from artists in 16 countries. Through a formal review process, we then selected two artists to work on this project: Noémie Ross from Canada, and Heta Nääs from Finland. With input from scientists, Noémie and Heta created fantastic cartoons that explain some of the changes happening to the environment in permafrost areas, how they affect people and wildlife, and what scientists are doing to better understand these changes to help people find innovative ways to adapt. We wish everyone plenty of fun reading this booklet and we would like to thank all those who supported this project.