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Abstract High-latitude and altitude cold regions are affected by climate warming and permafrost degradation. One of the major concerns associated with degrading permafrost is thaw subsidence (TS) due to melting of excess ground ice and associated thaw consolidation. Field observations, remote sensing, and numerical modeling are used to measure and estimate the extent and rates of TS across broad spatial and temporal scales. Our new data synthesis effort from diverse permafrost regions of North America and Eurasia, confirms widespread TS across the panarctic permafrost domain with rates of up to 2 cm yr⁻¹in the areas with low ice content and more than 3 cm yr⁻¹in regions with ice-rich permafrost. Areas with human activities or areas affected by wildfires exhibited higher subsidence rates. Our findings suggest that permafrost landscapes are undergoing geomorphic change that is impacting hydrology, ecosystems, and human infrastructure. The development of a systematic TS monitoring is urgently needed to deliver consistent and continuous exchange of data across different permafrost regions. Integration of coordinated field observations, remote sensing, and modeling of TS across a range of scales would contribute to better understanding of rapidly changing permafrost environments and resulting climate feedbacks. 

Abstract The 2015 spring flood of the Sagavanirktok River inundated large swaths of tundra as well as infrastructure near Prudhoe Bay, Alaska. Its lasting impact on permafrost, vegetation, and hydrology is unknown but compels attention in light of changing Arctic flood regimes. We combined InSAR and optical satellite observations to quantify subdecadal permafrost terrain changes and identify their controls. While the flood locally induced quasi‐instantaneous ice‐wedge melt, much larger areas were characterized by subtle, spatially variable post‐flood changes. Surface deformation from 2015 to 2019 estimated from ALOS‐2 and Sentinel‐1 InSAR varied substantially within and across terrain units, with greater subsidence on average in flooded locations. Subsidence exceeding 5 cm was locally observed in inundated ice‐rich units and also in inactive floodplains. Overall, subsidence increased with deposit age and thus ground ice content, but many flooded ice‐rich units remained stable, indicating variable drivers of deformation. On average, subsiding ice‐rich locations showed increases in observed greenness and wetness. Conversely, many ice‐poor floodplains greened without deforming. Ice wedge degradation in flooded locations with elevated subsidence was mostly of limited intensity, and the observed subsidence largely stopped within 2 years. Based on remote sensing and limited field observations, we propose that the disparate subdecadal changes were influenced by spatially variable drivers (e.g., sediment deposition, organic layer), controls (ground ice and its degree of protection), and feedback processes. Remote sensing helps quantify the heterogeneous interactions between permafrost, vegetation, and hydrology across permafrost‐affected fluvial landscapes. Interdisciplinary monitoring is needed to improve predictions of landscape dynamics and to constrain sediment, nutrient, and carbon budgets. 

This work coordinates data collection using standard equipment and protocols at North American and Russian sites. These data sets provide the baseline to assess the future rates of change in near-surface permafrost temperatures and permafrost boundaries, and to provide spatial data for validation of climate scenario models and temperature reanalysis approaches. The work represents the United States (US) contribution to the ongoing activities of the Global Terrestrial Network for Permafrost that obtains temperatures in a large number of globally distributed monitoring sites in order to provide a snapshot of permafrost temperatures in both time and space. The US National Science Foundation funded this work with award #0520578, #0632400, #0856864, and #1304271. 

This work coordinates data collection using standard equipment and protocols at North American and Russian sites. These data sets provide the baseline to assess the future rates of change in near-surface permafrost temperatures and permafrost boundaries, and to provide spatial data for validation of climate scenario models and temperature reanalysis approaches. The work represents the United States (US) contribution to the ongoing activities of the Global Terrestrial Network for Permafrost that obtains temperatures in a large number of globally distributed monitoring sites in order to provide a snapshot of permafrost temperatures in both time and space. The US National Science Foundation (NSF) funded this work with award #0520578, #0632400, #0856864, and #1304271. 

Accurate understanding of permafrost dynamics is critical for evaluating and mitigating impacts that may arise as permafrost degrades in the future; however, existing projections have large uncertainties. Studies of how permafrost responded historically during Earth’s past warm periods are helpful in exploring potential future permafrost behavior and to evaluate the uncertainty of future permafrost change projections. Here, we combine a surface frost index model with outputs from the second phase of the Pliocene Model Intercomparison Project to simulate the near‐surface (~3 to 4 m depth) permafrost state in the Northern Hemisphere during the mid-Pliocene warm period (mPWP, ~3.264 to 3.025 Ma). This period shares similarities with the projected future climate. Constrained by proxy-based surface air temperature records, our simulations demonstrate that near‐surface permafrost was highly spatially restricted during the mPWP and was 93 ± 3% smaller than the preindustrial extent. Near‐surface permafrost was present only in the eastern Siberian uplands, Canadian high Arctic Archipelago, and northernmost Greenland. The simulations are similar to near‐surface permafrost changes projected for the end of this century under the SSP5-8.5 scenario and provide a perspective on the potential permafrost behavior that may be expected in a warmer world. 

There has been a growth in the number of composite indicator tools used to assess community risk, vulnerability, and resilience, to assist study and policy planning. However, existing research shows that these composite indicators vary extensively in method, selected variables, aggregation methods, and sample size. The result is a plethora of qualitative and quantitative composite indices to choose from. Despite each providing valuable location-based information about specific communities and their qualities, the results of studies, each using disparate methods, cannot easily be integrated for use in decision making, given the different index attributes and study locations. Like many regions in the world, the Arctic is experiencing increased variability in temperatures as a direct consequence of a changing planetary climate. Cascading effects of changes in permafrost are poorly characterized, thus limiting response at multiple scales. We offer that by considering the spatial interaction between the effects of permafrost, infrastructure, and diverse patterns of community characteristics, existing research using different composite indices and frameworks can be augmented. We used a system-science and place-based knowledge approach that accounts for sub-system and cascade impacts through a proximity model of spatial interaction. An estimated ‘permafrost vulnerability surface’ was calculated across Alaska using two existing indices: relevant infrastructure and permafrost extent. The value of this surface in 186 communities and 30 military facilities was extracted and ordered to match the numerical rankings of the Denali Commission in their assessment of permafrost threat, allowing accurate comparison between the permafrost threat ranks and the PVI rankings. The methods behind the PVI provide a tool that can incorporate multiple risk, resilience, and vulnerability indices to aid adaptation planning, especially where large-scale studies with good geographic sample distribution using the same criteria and methods do not exist. 

This work coordinates data collection using standard equipment and protocols at the Alaskan and Russian borehole sites. These borehole temperature data sets provide the baseline to reconstruct past surface temperatures, to assess the future rates of change in near-surface permafrost temperatures and permafrost boundaries, and to provide spatial data for validation of climate scenario models and temperature reanalysis approaches. This represents the Russia contribution to the ongoing activities of Global Terrestrial Network for Permafrost that obtains temperatures in a large number of globally distributed boreholes in order to provide a snapshot of permafrost temperatures in both time and space. Included are files with the depth, temperature, and date of soil sampled at a number of sites. Site information (site name, latitude, longitude) by file name can be found in the file 'metadata_2022.csv'. 

Abstract. Soil pore water (SPW) chemistry can vary substantially acrossmultiple scales in Arctic permafrost landscapes. The magnitude of thesevariations and their relationship to scale are critical considerations forunderstanding current controls on geochemical cycling and for predictingfuture changes. These aspects are especially important for Arctic changemodeling where accurate representation of sub-grid variability may benecessary to predict watershed-scale behaviors. Our research goal is tocharacterize intra- and inter-watershed soil water geochemical variations attwo contrasting locations in the Seward Peninsula of Alaska, USA. We thenattempt to identify the key factors controlling concentrations of importantpore water solutes in these systems. The SPW geochemistry of 18 locationsspanning two small Arctic catchments was examined for spatial variabilityand its dominant environmental controls. The primary environmental controlsconsidered were vegetation, soil moisture and/or redox condition, water–soilinteractions and hydrologic transport, and mineral solubility. The samplinglocations varied in terms of vegetation type and canopy height, presence orabsence of near-surface permafrost, soil moisture, and hillslope position.Vegetation was found to have a significant impact on SPW NO3-concentrations, associated with the localized presence of nitrogen-fixingalders and mineralization and nitrification of leaf litter from tall willowshrubs. The elevated NO3- concentrations were, however, frequentlyequipoised by increased microbial denitrification in regions with sufficientmoisture to support it. Vegetation also had an observable impact on soil-moisture-sensitive constituents, but the effect was less significant. Theredox conditions in both catchments were generally limited by Fe reduction,seemingly well-buffered by a cache of amorphous Fe hydroxides, with the mostreducing conditions found at sampling locations with the highest soilmoisture content. Non-redox-sensitive cations were affected by a widevariety of water–soil interactions that affect mineral solubility andtransport. Identification of the dominant controls on current SPWhydrogeochemistry allows for qualitative prediction of future geochemicaltrends in small Arctic catchments that are likely to experience warming andpermafrost thaw. As source areas for geochemical fluxes to the broaderArctic hydrologic system, geochemical processes occurring in theseenvironments are particularly important to understand and predict withregards to such environmental changes.