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1. The Fate of Permafrost

   Panda, S. ( May 2017 , Alaska park science)

   Permafrost is ground that remains frozen year-round due to a cold climate; the active layer is the ground above the permafrost that thaws and re-freezes each year. Nearly 40 million acres of National Park Service (NPS) land in Alaska, similar to the size of Florida, lie within the zone of continuous or discontinuous permafrost. Permafrost can be classified as continuous (>90% of land area underlain by permafrost), discontinuous (90%-50%), sporadic (50%-10%), or isolated (<10%; Ferrians 1965). Permafrost is most vulnerable to climatic warming when its temperature is within a few degrees of thawing. Large-scale permafrost thawing would lead to a major reconfiguration of the landscape through the development of thermokarst (irregular topography resulting from ground ice melting). 

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2. Synthesis of physical processes of permafrost degradation and geophysical and geomechanical properties of permafrost

   https://doi.org/10.1016/j.coldregions.2022.103522  

   Liew, Min ; Ji, Xiaohang ; Xiao, Ming ; Farquharson, Louise ; Nicolsky, Dmitry ; Romanovsky, Vladimir ; Bray, Matthew ; Zhang, Xiong ; McComb, Christopher ( June 2022 , Cold Regions Science and Technology)
3. Modeling Long-Term Permafrost Degradation: HOW FAST PERMAFROST CAN THAW?

   https://doi.org/10.1029/2018JF004655  

   Nicolsky, D. J. ; Romanovsky, V. E. ( June 2018 , Journal of Geophysical Research: Earth Surface)

   Permafrost, as an important part of the Cryosphere, has been strongly affected by climate warming, and a wide spread of permafrost responses to the warming is currently observed. In particular, at some locations rather slow rates of permafrost degradations are noticed. We related this behavior to the presence of unfrozen water in frozen fine‐grained earth material. In this paper, we examine not‐very‐commonly‐discussed heat flux from the ground surface into the permafrost and consequently discuss implications of the presence of unfrozen liquid water on long‐term thawing of permafrost. We conducted a series of numerical experiments and demonstrated that the presence of fine‐grained material with substantial unfrozen liquid water content at below 0°C temperature can significantly slow down the thawing rate and hence can increase resilience of permafrost to the warming events. This effect is highly nonlinear, and a difference between the rates of thawing in fine‐ and coarse‐grained materials is more drastic for lower values of heat flux incoming into permafrost. For high heat flux, the difference between these rates almost disappears. As near‐surface permafrost temperature increases towards 0°C and the changes in the ground temperature become less evident, the future observation networks should try to incorporate measurements of unfrozen liquid water content in the near‐surface permafrost and heat flux into permafrost in addition to the existing temperature observations. 

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4. Past permafrost dynamics can inform future permafrost carbon-climate feedbacks

   https://doi.org/10.1038/s43247-023-00886-3  

   Jones, Miriam C. ; Grosse, Guido ; Treat, Claire ; Turetsky, Merritt ; Anthony, Katey Walter ; Brosius, Laura ( July 2023 , Communications Earth & Environment)

   Climate warming threatens to destabilize vast northern permafrost areas, potentially releasing large quantities of organic carbon that could further disrupt the climate. Here we synthesize paleorecords of past permafrost-carbon dynamics to contextualize future permafrost stability and carbon feedbacks. We identify key landscape differences between the last deglaciation and today that influence the response of permafrost to atmospheric warming, as well as landscape-level differences that limit subsequent carbon uptake. We show that the current magnitude of thaw has not yet exceeded that of previous deglaciations, but that permafrost carbon release has the potential to exert a strong feedback on future Arctic climate as temperatures exceed those of the Pleistocene. Better constraints on the extent of subsea permafrost and its carbon pool, and on carbon dynamics from a range of permafrost thaw processes, including blowout craters and megaslumps, are needed to help quantify the future permafrost-carbon-climate feedbacks.

    

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5. Coastal Permafrost Erosion

   https://doi.org/10.25923/e47w-dw52  

   Jones, B.M. ; Irrgang, A.M. ; Farquharson, L.M. ; Lantuit, H. ; Whalen, D. ; Ogorodov, S. ; Grigoriev, M. ; Tweedie, C. ; Gibbs, A.E. ; Strzelecki, M.C. ; et al ( January 2020 , Arctic report card)

   Thoman, R.L. ; Richter-Menge, J. ; Druckenmiller, M.L. (Ed.)

   Since the early 2000s, observations from 14 coastal permafrost sites have been updated, providing a synopsis of how changes in the Arctic System are intensifying the dynamics of permafrost coasts in the 21st Century. Observations from all but 1 of the 14 permafrost coastal sites around the Arctic indicate that decadal-scale erosion rates are increasing. The US and Canadian Beaufort Sea coasts have experienced the largest increases in erosion rates since the early-2000s. The mean annual erosion rate in these regions has increased by 80 to 160 % at the five sites with available data, with sites in the Canadian Beaufort Sea experiencing the largest relative increase. The sole available site in the Greenland Sea, on southern Svalbard, indicates an increase in mean annual erosion rates by 66 % since 2000, due primarily to a reduction in nearshore sediment supply from glacial recession. At the five sites along the Barents, Kara, and Laptev Seas in Siberia, mean annual erosion rates increased between 33 and 97 % since the early to mid-2000s. The only site to experience a decrease in mean annual erosion (- 40%) was located in the Chukchi Sea in Alaska. Interestingly, the other site in the Chukchi Sea experienced one of the highest increases in mean annual erosion (+160%) over the same period. In general, a considerable increase in the variability of erosion and deposition intensity was also observed along most of the sites. 

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